RPCManager (Smart GWT LGPL Edition API 12.1p (2024-11-05))

java.lang.Object
- com.smartgwt.client.rpc.RPCManager

```
public class RPCManager
extends java.lang.Object
```
RPCManager is a static singleton class that manages transparent client/server RPC (remote procedure call). This class provides a generic, low-level client/server communication integration point.
Smart GWT's powerful databinding subsystem (see DataSource, DataBoundComponents) automatically make use of this class to issue RPCs as necessary, based on the DataSource protocol. To integrate DataBoundComponents with your server, start here.
For arbitrary client/server interactions outside of the DataSource subsystem, the Smart GWT server also provides the Direct Method Invocation feature.
The RPCManager class can also be used directly to send data to a URL of your choosing and optionally be called back with server-returned data when the server replies.
The Smart GWT server code has APIs for processing RPC requests providing features such as automatic Java <--> JavaScript object translation and handling of queued requests.
The IDACall servlet makes use of these features to handle standard DataSource requests and DMI calls. Developers can also override the actionURL of specific requests and use these APIs directly in a JSP, Servlet or Filter.
Note: the client-side RPCManager class can also be used without the Smart GWT server. For an overview of client/server interactions without the Smart GWT server, see this overview.
Simple arbitrary Remote Procedure Call example (client code):
```
   RPCRequest request = new RPCRequest();
   // Note data could be a String, Map or Record
   request.setData("Some data to send to the client");
   request.setActionURL("/rpcHandler.jsp");
  
   RPCManager.sendRequest(request, 
       new RPCCallback () {
           public void execute(RPCResponse response, Object rawData, RPCRequest request) {
               SC.say("Response from the server:" + rawData);
           }
       }
   );
  
```
Simple arbitrary Remote Procedure Call example (server code: /rpcHandler.jsp):
```
  RPCManager rpc = new RPCManager(request, response, out);
  Object data = rpc.getData();
  System.out.println("client sent: " + data.toString());
  rpc.send("here's a response");
  
```
Queuing
Because of browser limitations on the total number of simultaneous HTTP connections to a given server, batching multiple RPC requests into a single HTTP request is highly advisable whenever possible. The RPCManager provides a queuing mechanism that allows this.

Queuing example (client code):
```
  boolean wasQueuing = RPCManager.startQueue();
   
  RPCCallback callback = new RPCCallback() {
      public void execute(RPCResponse response, Object rawData, RPCRequest request) {
          Window.alert("response from server:" + rawData);
      }
  };
    
  RPCRequest request1 = new RPCRequest();
  request1.setActionURL("/rpcHandler.jsp");
  request1.setData("A String of Data");
  RPCManager.sendRequest(request1, callback);
    
  RPCRequest request2 = new RPCRequest();
  request2.setActionURL("/rpcHandler.jsp");
  request2.setData("Another String of Data");
  RPCManager.sendRequest(request2, callback);
    
  if (!wasQueuing) RPCManager.sendQueue();
  
```
Queuing example (server code: /rpcHandler.jsp):
```
  RPCManager rpc = new RPCManager(request, response, out);
 
  for(Iterator i = rpc.getRequests().iterator(); i.hasNext();) {
      RPCRequest rpcRequest = (RPCRequest)i.next();
      Object data = rpcRequest.getData();
      System.out.println("client sent:" + data.toString());
 
      //send back the data sent to us by the client
      rpc.send(rpcRequest, new RPCResponse(data));
  }

  
```
Error Handling

Please see this separate article on error handling.

Field Summary

Fields
Modifier and Type Field and Description

static java.lang.String ALL_GLOBALS
ALL_GLOBALS constant used by the loadScreen(String, LoadScreenCallback, String[]) API.

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`ALL_GLOBALS` ALL_GLOBALS constant used by the `loadScreen(String, LoadScreenCallback, String[])` API.

Constructor Summary

Constructors
Constructor and Description

RPCManager()

Constructors
Constructor and Description
`RPCManager()`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static void`	`cacheScreens(java.lang.String[] screenName, Function callback)` Loads the definitions of a set of screens saved in `Component XML` format, using the `ScreenLoaderServlet`.
`static void`	`cacheScreens(java.lang.String[] screenName, Function callback, java.lang.String locale)`
`static void`	`cacheScreens(java.lang.String[] screenName, Function callback, java.lang.String locale, RPCRequest requestProperties)` Loads the definitions of a set of screens saved in `Component XML` format, using the `ScreenLoaderServlet`.
`static void`	`cancelDefaultErrorHandling()` Cancels default error handling for all `DSResponse`s in the current transaction, ensuring that the default error handling or current `error handler` is not called for any of them.
`static void`	`cancelQueue()` Cancel a queue of requests (also called a transaction).
`static void`	`cancelQueue(int transactionNum)` Cancel a queue of requests (also called a transaction).
`static void`	`cancelQueue(java.lang.String transactionNum)` Deprecated. please use int methods when dealing with transaction number.
`static void`	`clearTransaction(int transactionNum)` Erase all client-side record of a transaction, such that any response from the server will be ignored.
`static void`	`clearTransaction(java.lang.String transactionNum)` Deprecated. please use int methods when dealing with transaction number.
`static Canvas`	`createScreen(java.lang.String screenName)` Creates a screen previously cached by a call to `cacheScreens()`.
`static Canvas`	`createScreen(java.lang.String screenName, CreateScreenSettings globals)` Creates a screen previously cached by a call to `cacheScreens()`.
`static Canvas`	`createScreen(java.lang.String screenName, java.lang.String[] globals)` Creates a screen previously cached by a call to `cacheScreens()`.
`static void`	`customizeTransforms(RequestTransformer requestTransformer)` Apply the specified `RequestTransformer` to override the default behavior of `transformRequest(RPCRequest)`.
`static void`	`exportContent(Canvas canvas)` Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
`static void`	`exportContent(Canvas[] canvas)` Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
`static void`	`exportContent(Canvas[] components, DSRequest requestProperties)` Converts `printable HTML` generated from live UI components into a .pdf and downloads it ("Save As.." dialog).
`static void`	`exportContent(Canvas canvas, DSRequest requestProperties)` Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
`static void`	`exportContent(java.lang.String canvas)` Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
`static void`	`exportContent(java.lang.String htmlFragment, DSRequest requestProperties)` Converts `printable HTML` generated from live UI components into a .pdf and downloads it ("Save As.." dialog).
`static void`	`exportImage(java.lang.String svgString)`
`static void`	`exportImage(java.lang.String svgString, DSRequest requestProperties)`
`static void`	`exportImage(java.lang.String svgString, DSRequest requestProperties, ExportImageCallback callback)` Converts an SVG string to one of several possible image formats, and can either initiate a download or return the base64-encoded image data.
`static java.lang.String`	`getActionURL()` Specifies the default URL for RPCRequests and DSRequests that do not specify a URL.
`static java.lang.String`	`getCredentialsURL()` Specifies URL where credentials should be submitted to attempt relogin when session timeout is encountered during a background RPC.
`static java.lang.String`	`getCurrentTransactionId()` Deprecated. please use int methods when dealing with transaction number.
`static int`	`getCurrentTransactionIdAsInt()` Same as getQueueTransactionId() but returns `-1` instead of `null` if there's no currently queued requests.
`static java.lang.String`	`getLoginRequiredMarker()` Marker the system will look for in order to detect when login is required.
`static java.lang.String`	`getLoginStatusCodeMarker()` String sequence which marks the response as a one which contains login status information.
`static java.lang.String`	`getLoginSuccessMarker()` Marker the system will look for in order to detect when login was successfull.
`static void`	`getMaxLoginAttemptsExceededMarker()` Get the marker the system will look for in order to detect when the number of maximum logins was exceeded.
`static java.lang.Integer`	`getQueueTransactionId()` Returns the id of the current transaction (a queue of requests).
`static java.lang.Boolean`	`hasCurrentTransactionQueued()` Returns true if there is a current transaction (queue of requests)
`static void`	`isScreenCached(java.lang.String screenName)` Returns true if a screen with the given name has already been cached by a call to `cacheScreens()` (or `loadProject()`), false otherwise.
`static void`	`loadProject(java.lang.String projectNames, Function callback, LoadProjectSettings settings)` Loads projects using the `ProjectLoaderServlet`, reachable at `projectLoaderURL`, and fires the given callback after screens have been `cached`.
`static void`	`loadScreen(java.lang.String screenName, LoadScreenCallback callback)` Loads a screen saved in `Component XML` format.
`static void`	`loadScreen(java.lang.String screenName, LoadScreenCallback callback, java.lang.String[] globals)` Loads a screen saved in `Component XML` format.
`static void`	`loadScreen(java.lang.String screenName, LoadScreenCallback callback, java.lang.String[] globals, RPCRequest requestProperties)` Loads a screen saved in `Component XML` format.
`static void`	`loadScreen(java.lang.String screenName, LoadScreenCallback callback, java.lang.String[] globals, java.lang.String locale, RPCRequest requestProperties)` Loads a screen saved in `Component XML` format, using the `ScreenLoaderServlet`.
`static java.lang.Boolean`	`requestsArePending()` Returns whether there are any pending RPC requests.
`static void`	`resendTransaction()` Resend a suspended transaction to the server.
`static void`	`resendTransaction(int transactionNum)` Resend a suspended transaction to the server.
`static void`	`resendTransaction(java.lang.String transactionNum)` Deprecated. please use int methods when dealing with transaction number.
`static void`	`runDefaultErrorHandling(DSResponse response, DSRequest request)` Runs the default error handling normally performed by `HandleErrorCallback.handleError()`.
`static void`	`send(com.google.gwt.core.client.JavaScriptObject data, RPCCallback callback, java.util.Map requestParams)` This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
`static void`	`send(com.google.gwt.core.client.JavaScriptObject data, RPCCallback callback, RPCRequest requestParams)` This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
`static void`	`send(java.lang.String data, RPCCallback callback, java.util.Map requestParams)` This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
`static void`	`send(java.lang.String data, RPCCallback callback, RPCRequest requestParams)` This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
`static void`	`sendProxied(RPCRequest request, RPCCallback callback)` Send an HTTP request to a remote host, potentially through the HttpProxy servlet installed on the Smart GWT Server.
`static void`	`sendQueue()` Send all currently queued requests to the server.
`static void`	`sendQueue(RPCQueueCallback callback)` Send all currently queued requests to the server.
`static void`	`sendRequest(RPCRequest rpcRequestProperties)` Send the passed RPCRequest to the server.
`static void`	`sendRequest(RPCRequest rpcRequestProperties, RPCCallback callback)` Send the passed RPCRequest to the server.
`static void`	`setActionURL(java.lang.String actionURL)` Specifies the default URL for RPCRequests and DSRequests that do not specify a URL.
`static void`	`setAllowCrossDomainCalls(java.lang.Boolean allowCrossDomainCalls)` By default Smart GWT will show a warning message on attempted requests to another domain as this is usually not supported at the browser level by default due to security considerations.
`static void`	`setAllowIE9Leak(boolean allowLeak)` In Internet Explorer 9, when a string of JavaScript is evaluated via the native `eval()` function, objects created within that evaluation are not released from browser memory until the page is reloaded.
`static void`	`setCredentialsURL(java.lang.String credentialsURL)` Specifies URL where credentials should be submitted to attempt relogin when session timeout is encountered during a background RPC.
`static void`	`setDefaultPrompt(java.lang.String defaultPrompt)` If showPrompt is enabled for a given transaction, this is the defaultPrompt to be shown to the user in a modal dialog while the transaction occurs.
`static void`	`setDefaultTimeout(double defaultTimeout)` In milliseconds, how long the RPCManager waits for an RPC request to complete before returning an error.
`static void`	`setFetchDataPrompt(java.lang.String fetchDataPrompt)` Default prompt displayed to the user while an operation is running to fetch data from the server.
`static void`	`setHandleErrorCallback(HandleErrorCallback callback)` `handleError()` will be called if `RPCResponse.status` is negative and `RPCRequest.willHandleError` was not set.
`static void`	`setHandleTransportErrorCallback(HandleTransportErrorCallback callback)` Sets callback to handle server error responses for submitted transactions.
`static void`	`setLoginRequiredCallback(LoginRequiredCallback callback)` Called when a session timeout is encountered while trying to do a background RPC.
`static void`	`setLoginRequiredMarker(java.lang.String loginRequiredMarker)` Marker the system will look for in order to detect when login is required.
`static void`	`setLoginStatusCodeMarker(java.lang.String loginStatusCodeMarker)` String sequence which marks the response as a one which contains login status information.
`static void`	`setLoginSuccessMarker(java.lang.String loginSuccessMarker)` Marker the system will look for in order to detect when login was successfull.
`static java.lang.String`	`setMaxLoginAttemptsExceededMarker(java.lang.String maxLoginAttemptsExceededMarker)` Set the marker the system will look for in order to detect when the number of maximum logins was exceeded.
`static void`	`setPromptCursor(java.lang.String promptCursor)` Controls the default cursor shown when RPCManager.promptStyle is set to "cursor".
`static void`	`setPromptStyle(PromptStyle promptStyle)` Controls the default prompt style.
`static void`	`setQueueSentCallback(QueueSentCallback callback)` This method is called by the RPCManager every time it sends a queue of requests to the server (note that if you are not using queuing, the system simply sends queues containing just one request, so this API is valid regardless).
`static void`	`setRemoveDataPrompt(java.lang.String removeDataPrompt)` Default prompt displayed to user while an operation is running to remove data from the server.
`static void`	`setSaveDataPrompt(java.lang.String saveDataPrompt)` Default prompt displayed to the user while an operation is running to save data to the server.
`static void`	`setShowPrompt(boolean showPrompt)` If set to `true`, the RPCManager will block the UI with a modal dialog containing the text from RPCManager.defaultPrompt (or the per-RPCRequest override) until the RPC to the server completes.
`static void`	`setTimeoutErrorMessage(java.lang.String timeoutErrorMessage)` Default message displayed to user when an operation fails to return from the server within the timeout period specified by `defaultTimeout`.
`static void`	`setUseCursorTracking(boolean useCursorTracking)` If true, an image is shown to the right of the cursor when RPCRequest.promptStyle is set to "cursor", otherwise the cursor itself is modified via css to the value of RPCRequest.promptCursor.
`static void`	`setUseHttpProxy(java.lang.Boolean useHttpProxy)` Whether the `HttpProxyServlet` should be used in order to get around the "same origin policy" that prevents web pages from contacting other sites.
`static boolean`	`startQueue()` Start queuing `DSRequests` and `RPCRequests` system-wide, for later sending when RPCManager.sendQueue() is called, at which time all queued requests will be sent as a single, combined HTTP request.
`static boolean`	`startQueue(boolean shouldQueue)` Start queuing `DSRequests` and `RPCRequests` system-wide, for later sending when RPCManager.sendQueue() is called, at which time all queued requests will be sent as a single, combined HTTP request.
`static void`	`suspendTransaction()` Suspends the current transaction, such that all processing of the transaction is halted, any remaining `callback` in the transaction won't fire, and the transaction can never `timeout`.
`static void`	`suspendTransaction(int transactionID)` Suspends the current transaction, such that all processing of the transaction is halted, any remaining `callback` in the transaction won't fire, and the transaction can never `timeout`.
`static void`	`suspendTransaction(java.lang.String transactionID)` Deprecated. please use int methods when dealing with transaction number.
`static java.lang.Object`	`transformRequest(RPCRequest rpcRequest)` Returns the data that should be sent to the `actionURL`.
`static java.lang.Boolean`	`xmlHttpRequestAvailable()` Returns true if the XMLHttpRequest object is available, false otherwise.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ALL_GLOBALS
```
public static final java.lang.String ALL_GLOBALS
```
    ALL_GLOBALS constant used by the loadScreen(String, LoadScreenCallback, String[]) API.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - RPCManager
```
public RPCManager()
```
- Method Detail
  - setActionURL
```
public static void setActionURL(java.lang.String actionURL)
```
    Specifies the default URL for RPCRequests and DSRequests that do not specify a URL.
    URLs can be set on a per-request basis via RPCRequest.actionURL, or on a per-DataSource or per-operationType basis via DataSource.dataURL and OperationBinding.dataURL respectively. However, note that in order to be able to make use of queuing, you should have all data loading and saving requests go to a single URL unless you are forced to use distinct URLs by legacy services.
    The primary use case for setting the default actionURL is to add a CSRF / XSRF (Cross-site Request Forgery) token. Assuming you are using a single URL for all data requests as covered above, adding a CSRF token to the default actionURL as a simple HTTP parameter will cause the CSRF token to be included in all RPCRequests and DSRequests from all DataSources without further effort.
    If the actionURL is changed while transactions are suspended, any suspended transactions whose actionURL was defaulted to this property (e.g. because RPCRequest.actionURL wasn't set) will be updated to have the new actionURL.
    
    Parameters:
    
    actionURL - new actionURL. Default value is RPCManager.actionURL.
  - getActionURL
```
public static java.lang.String getActionURL()
```
    Specifies the default URL for RPCRequests and DSRequests that do not specify a URL.
    URLs can be set on a per-request basis via RPCRequest.actionURL, or on a per-DataSource or per-operationType basis via DataSource.dataURL and OperationBinding.dataURL respectively. However, note that in order to be able to make use of queuing, you should have all data loading and saving requests go to a single URL unless you are forced to use distinct URLs by legacy services.
    The primary use case for setting the default actionURL is to add a CSRF / XSRF (Cross-site Request Forgery) token. Assuming you are using a single URL for all data requests as covered above, adding a CSRF token to the default actionURL as a simple HTTP parameter will cause the CSRF token to be included in all RPCRequests and DSRequests from all DataSources without further effort.
    If the actionURL is changed while transactions are suspended, any suspended transactions whose actionURL was defaulted to this property (e.g. because RPCRequest.actionURL wasn't set) will be updated to have the new actionURL.
    
    Returns:
    
    current value of actionURL
  - setAllowCrossDomainCalls
```
public static void setAllowCrossDomainCalls(java.lang.Boolean allowCrossDomainCalls)
```
    By default Smart GWT will show a warning message on attempted requests to another domain as this is usually not supported at the browser level by default due to security considerations.
    Some browsers now do support cross domain requests through the use of Http Access Control headers (See the W3C Cross-Origin Resource Sharing recommendation). If your application intends to rely on this behavior to perform cross-domain requests, you can set allowCrossDomainCalls to true to disable the standard Smart GWT warning when such calls occur.
    Note also that this is typically not an issue if you are using the Smart GWT server (part of Pro, Power and Enterprise editions of Smart GWT), as this includes the HTTPProxy servlet.
    
    Parameters:
    
    allowCrossDomainCalls - new allowCrossDomainCalls. Default value is false.
  - setCredentialsURL
```
public static void setCredentialsURL(java.lang.String credentialsURL)
```
    Specifies URL where credentials should be submitted to attempt relogin when session timeout is encountered during a background RPC. See Relogin
    
    Parameters:
    
    credentialsURL - new credentialsURL. Default value is http://localhost:8080/isomorphic/login/loginSuccessMarker.html.
  - getCredentialsURL
```
public static java.lang.String getCredentialsURL()
```
    Specifies URL where credentials should be submitted to attempt relogin when session timeout is encountered during a background RPC. See Relogin
    
    Returns:
    
    current value of credentialsURL
  - setLoginRequiredMarker
```
public static void setLoginRequiredMarker(java.lang.String loginRequiredMarker)
```
    Marker the system will look for in order to detect when login is required.
    The default loginRequired marker should generally not be customized. It is designed to be safe to insert into any HTML page or other server response without affecting display or functionality, for example, within an HTML comment. You should *only* customize the loginRequiredMarker if you have absolutely no ability to change the response that the server will send when login is required.
    If you do customize the loginRequiredMarker, then the loginRequiredMarker, loginSuccessMarker and maxLoginAttemptsExceededMarker should all start with the loginStatusCodeMarker. If they do not, there will be a small impact on performance as every response must be separately scanned for each marker, instead of just scanning once for the loginStatusCodeMarker.
    In addition, the loginStatusCodeMarker should ideally contain text that could not possibly validly appear as a data value in a normal response, since if that were possible, end users could enter the loginRequiredMarker as a data value and cause Smart GWT to falsely detect session timeout when handling an ordinary data response. This is why the default marker has characters that make it impossible for it to be validly interpreted as a JavaScript String, XML document or HTML content - there is no way that an end user could enter this as a data value in an application and have it appear verbatim in a server response.
    
    Parameters:
    
    loginRequiredMarker - new loginRequiredMarker. Default value is <SCRIPT>//'\"]]>>isc_loginRequired.
  - getLoginRequiredMarker
```
public static java.lang.String getLoginRequiredMarker()
```
    Marker the system will look for in order to detect when login is required.
    The default loginRequired marker should generally not be customized. It is designed to be safe to insert into any HTML page or other server response without affecting display or functionality, for example, within an HTML comment. You should *only* customize the loginRequiredMarker if you have absolutely no ability to change the response that the server will send when login is required.
    If you do customize the loginRequiredMarker, then the loginRequiredMarker, loginSuccessMarker and maxLoginAttemptsExceededMarker should all start with the loginStatusCodeMarker. If they do not, there will be a small impact on performance as every response must be separately scanned for each marker, instead of just scanning once for the loginStatusCodeMarker.
    In addition, the loginStatusCodeMarker should ideally contain text that could not possibly validly appear as a data value in a normal response, since if that were possible, end users could enter the loginRequiredMarker as a data value and cause Smart GWT to falsely detect session timeout when handling an ordinary data response. This is why the default marker has characters that make it impossible for it to be validly interpreted as a JavaScript String, XML document or HTML content - there is no way that an end user could enter this as a data value in an application and have it appear verbatim in a server response.
    
    Returns:
    
    current value of loginRequiredMarker
  - setLoginStatusCodeMarker
```
public static void setLoginStatusCodeMarker(java.lang.String loginStatusCodeMarker)
```
    String sequence which marks the response as a one which contains login status information.
    
    Parameters:
    
    loginStatusCodeMarker - new loginStatusCodeMarker. Default value is <SCRIPT>//'\"]]>>isc_.
  - getLoginStatusCodeMarker
```
public static java.lang.String getLoginStatusCodeMarker()
```
    String sequence which marks the response as a one which contains login status information.
    
    Returns:
    
    current value of loginStatusCodeMarker
  - setLoginSuccessMarker
```
public static void setLoginSuccessMarker(java.lang.String loginSuccessMarker)
```
    Marker the system will look for in order to detect when login was successfull.
    
    Parameters:
    
    loginSuccessMarker - new loginSuccessMarker. Default value is <SCRIPT>//'\"]]>>isc_loginSuccess.
  - getLoginSuccessMarker
```
public static java.lang.String getLoginSuccessMarker()
```
    Marker the system will look for in order to detect when login was successfull.
    
    Returns:
    
    current value of loginSuccessMarker
  - setShowPrompt
```
public static void setShowPrompt(boolean showPrompt)
```
    If set to true, the RPCManager will block the UI with a modal dialog containing the text from RPCManager.defaultPrompt (or the per-RPCRequest override) until the RPC to the server completes.
    If set to false, the RPC happens transparently, allowing the user to continue interacting with the UI.
    DataSource requests, which are a particular type of RPCRequest, are controlled by the more-specific DataSource-level setting DataSource.showPrompt.
    
    Parameters:
    
    showPrompt - new showPrompt. Default value is RPCManager.showPrompt.
  - setTimeoutErrorMessage
```
public static void setTimeoutErrorMessage(java.lang.String timeoutErrorMessage)
```
    Default message displayed to user when an operation fails to return from the server within the timeout period specified by defaultTimeout.
    
    Parameters:
    
    timeoutErrorMessage - new timeoutErrorMessage. Default value is "Operation timed out".
  - setUseHttpProxy
```
public static void setUseHttpProxy(java.lang.Boolean useHttpProxy)
```
    Whether the HttpProxyServlet should be used in order to get around the "same origin policy" that prevents web pages from contacting other sites.
    Default behavior is to use the HttpProxyServlet whenever a URL appears to be pointing to another site. Set RPCRequest.useHttpProxy false to have a particular request avoid using the HttpProxyServlet even when it appears to be necessary, or set RPCManager.useHttpProxy to false to avoid ever attempting to use the HttpProxyServlet.
    
    Parameters:
    
    useHttpProxy - new useHttpProxy. Default value is true.
  - cacheScreens
```
public static void cacheScreens(java.lang.String[] screenName,
                                Function callback)
```
    Loads the definitions of a set of screens saved in Component XML format, using the ScreenLoaderServlet.
    Unlike loadScreen(), cacheScreens() does not cause any UI components to be created or drawn, it just loads the definitions of the screens. This allows a subsequent, synchronous call to createScreen() to create the actual screen, rather than contacting the ScreenLoader servlet and showing a loading message.
    See loadScreen() for the meaning of the locale parameter.
    Calling cacheScreens twice with the same screenName will re-load the definition of that screen from the server such that subsequent calls to createScreen() will use the new definition.
    
    Parameters:
    
    screenName - name of the screens to cache
    
    callback - callback for notification of screens being successfully cached
  - cacheScreens
```
public static void cacheScreens(java.lang.String[] screenName,
                                Function callback,
                                java.lang.String locale)
```
    See Also:
    
    cacheScreens(java.lang.String[], com.smartgwt.client.core.Function)
  - cacheScreens
```
public static void cacheScreens(java.lang.String[] screenName,
                                Function callback,
                                java.lang.String locale,
                                RPCRequest requestProperties)
```
    Loads the definitions of a set of screens saved in Component XML format, using the ScreenLoaderServlet.
    Unlike loadScreen(), cacheScreens() does not cause any UI components to be created or drawn, it just loads the definitions of the screens. This allows a subsequent, synchronous call to createScreen() to create the actual screen, rather than contacting the ScreenLoader servlet and showing a loading message.
    See loadScreen() for the meaning of the locale parameter.
    Calling cacheScreens twice with the same screenName will re-load the definition of that screen from the server such that subsequent calls to createScreen() will use the new definition.
    
    Parameters:
    
    screenName - name of the screens to cache
    
    callback - callback for notification of screens being successfully cached
    
    locale - The name of a locale to use for resolving i18n tags in the component XML of the screen
    
    requestProperties - optional properties for the request
  - cancelQueue
```
public static void cancelQueue()
```
    Cancel a queue of requests (also called a transaction).
    If a transactionId is passed, that transaction will be cancelled, otherwise, the current (not yet sent) transaction is cancelled. You can retrieve the id of the current transaction, if there is one, by calling getQueueTransactionId() before the transaction has been sent.
    Note that cancelQueue() calls clearTransaction() and attempts to abort the request. However, note also that whilst cancelling a transaction that has already been sent will not necessarily stop the HTTP request that has been issued - this is only possible on some browsers and with some transports - it will reliably cause Smart GWT to ignore any response returned by the server and not fire any callbacks that have been passed in.
    Also, take into account that this method removes all queued requests from the current queue, but queueing is still active, so if you also want to disable queuing you should call startQueue(false).
  - cancelQueue
```
public static void cancelQueue(int transactionNum)
```
    Cancel a queue of requests (also called a transaction).
    If a transactionId is passed, that transaction will be cancelled, otherwise, the current (not yet sent) transaction is cancelled. You can retrieve the id of the current transaction, if there is one, by calling getQueueTransactionId() before the transaction has been sent.
    Note that cancelQueue() calls clearTransaction() and attempts to abort the request. However, note also that whilst cancelling a transaction that has already been sent will not necessarily stop the HTTP request that has been issued - this is only possible on some browsers and with some transports - it will reliably cause Smart GWT to ignore any response returned by the server and not fire any callbacks that have been passed in.
    Also, take into account that this method removes all queued requests from the current queue, but queueing is still active, so if you also want to disable queuing you should call startQueue(false).
    
    Parameters:
    
    transactionNum - transactionId of the queue.
  - clearTransaction
```
public static void clearTransaction(int transactionNum)
```
    Erase all client-side record of a transaction, such that any response from the server will be ignored.
    A transaction means a batch of one or more RPCRequests that have already been sent to the server via sendQueue().
    You can retrieve the id of the current transaction, if there is one, by getQueueTransactionId() before the transaction is sent.
    
    Parameters:
    
    transactionNum - id of the transaction to be cleared
  - createScreen
```
public static Canvas createScreen(java.lang.String screenName)
```
    Creates a screen previously cached by a call to cacheScreens().
    As with loadScreen(), the default behavior is to prevent any global widget IDs from being established, the returned Canvas will be the outermost component of the screen, and that Canvas will provide access to other widgets in the screen via getByLocalId()
    Alternatively, as with loadScreen(), a list of IDs that should be allowed to become globals can be passed, allowing those widgets to be retrieved via a call to Canvas.getById() after the screen has been created.
    If you do not pass globals and avoid depending on global IDs within the screen definition itself (for example, by embedding JavaScript event handlers in the screen definition that use global IDs), you can create the same screen multiple times.
    Creating a screen may or may not cause it to draw, depending on current global autoDraw setting (isc.setAutoDraw()) and any autoDraw settings in the screen itself.
    Instead of globals, you may instead pass a substitution configuration to change what classes are used to construct widgets, or subsitute existing widgets for those to be constructed, by widget ID.
    
    Parameters:
    
    screenName - name of the screen to create
    
    Returns:
    
    last top-level widget in the screen definition
  - createScreen
```
public static Canvas createScreen(java.lang.String screenName,
                                  java.lang.String[] globals)
```
    Creates a screen previously cached by a call to cacheScreens().
    As with loadScreen(), the default behavior is to prevent any global widget IDs from being established, the returned Canvas will be the outermost component of the screen, and that Canvas will provide access to other widgets in the screen via getByLocalId()
    Alternatively, as with loadScreen(), a list of IDs that should be allowed to become globals can be passed, allowing those widgets to be retrieved via a call to Canvas.getById() after the screen has been created.
    If you do not pass globals and avoid depending on global IDs within the screen definition itself (for example, by embedding JavaScript event handlers in the screen definition that use global IDs), you can create the same screen multiple times.
    Creating a screen may or may not cause it to draw, depending on current global autoDraw setting (isc.setAutoDraw()) and any autoDraw settings in the screen itself.
    Instead of globals, you may instead pass a substitution configuration to change what classes are used to construct widgets, or subsitute existing widgets for those to be constructed, by widget ID.
    
    Parameters:
    
    screenName - name of the screen to create
    
    globals - widgets to allow to take their global IDs, or a widget remap config
    
    Returns:
    
    last top-level widget in the screen definition
  - exportContent
```
public static void exportContent(Canvas canvas)
```
    Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
    As with other exports, the resulting file can be saved to the server filesystem instead of, or in addition to being downloaded to the user. See server-side docs for com.isomorphic.contentexport.PdfExport for more details on server-side processing and code samples for redirecting PDF output to a file or in-memory buffer, as well as instructions for adding additional stylesheets.
    You can either pass any Canvas to exportContent, or you can pass HTML that you have retrieved by calling Canvas.getPrintHTML(). When calling getPrintHTML() to retrieve HTML for use with exportContent(), you must pass the PrintProperties.printForExport or DrawPane and FacetChart instances will not export properly.
    You can use a custom skin when exporting your HTML content. To use a custom skin, add a line to server.properties:
```
    skin.{skinName}.location: custom/skin
  
```
    Where {skinName} is the name of your custom skin, and the value is the path to your skin resources from the application webroot.
    Also, you can set the filename of the export via DSRequest.exportFilename. For example:
```
  DSRequest requestProperties = new DSRequest();
  requestProperties.setAttribute("exportFilename", "export");
  
```
    In case you do not provide a filename for your export, the system will assign the default filename "export".
    Requires the Smart GWT server framework, but does not require use of server-based databinding - no .ds.xml files need to exist.
    You can also inject a small amount of CSS from the browser via DSRequest.exportCSS - this is intended primarily for switching the page size on the fly, for exceptionally wide or tall exports.
    Parameters:
    
    canvas - Canvas or canvas list that has exportable widgets, or an HTML fragment derived from getPrintHTML()
  - exportContent
```
public static void exportContent(Canvas[] canvas)
```
    Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
    As with other exports, the resulting file can be saved to the server filesystem instead of, or in addition to being downloaded to the user. See server-side docs for com.isomorphic.contentexport.PdfExport for more details on server-side processing and code samples for redirecting PDF output to a file or in-memory buffer, as well as instructions for adding additional stylesheets.
    You can either pass any Canvas to exportContent, or you can pass HTML that you have retrieved by calling Canvas.getPrintHTML(). When calling getPrintHTML() to retrieve HTML for use with exportContent(), you must pass the PrintProperties.printForExport or DrawPane and FacetChart instances will not export properly.
    You can use a custom skin when exporting your HTML content. To use a custom skin, add a line to server.properties:
```
    skin.{skinName}.location: custom/skin
  
```
    Where {skinName} is the name of your custom skin, and the value is the path to your skin resources from the application webroot.
    Also, you can set the filename of the export via DSRequest.exportFilename. For example:
```
  DSRequest requestProperties = new DSRequest();
  requestProperties.setAttribute("exportFilename", "export");
  
```
    In case you do not provide a filename for your export, the system will assign the default filename "export".
    Requires the Smart GWT server framework, but does not require use of server-based databinding - no .ds.xml files need to exist.
    You can also inject a small amount of CSS from the browser via DSRequest.exportCSS - this is intended primarily for switching the page size on the fly, for exceptionally wide or tall exports.
    Parameters:
    
    canvas - Canvas or canvas list that has exportable widgets, or an HTML fragment derived from getPrintHTML()
  - exportContent
```
public static void exportContent(java.lang.String canvas)
```
    Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
    As with other exports, the resulting file can be saved to the server filesystem instead of, or in addition to being downloaded to the user. See server-side docs for com.isomorphic.contentexport.PdfExport for more details on server-side processing and code samples for redirecting PDF output to a file or in-memory buffer, as well as instructions for adding additional stylesheets.
    You can either pass any Canvas to exportContent, or you can pass HTML that you have retrieved by calling Canvas.getPrintHTML(). When calling getPrintHTML() to retrieve HTML for use with exportContent(), you must pass the PrintProperties.printForExport or DrawPane and FacetChart instances will not export properly.
    You can use a custom skin when exporting your HTML content. To use a custom skin, add a line to server.properties:
```
    skin.{skinName}.location: custom/skin
  
```
    Where {skinName} is the name of your custom skin, and the value is the path to your skin resources from the application webroot.
    Also, you can set the filename of the export via DSRequest.exportFilename. For example:
```
  DSRequest requestProperties = new DSRequest();
  requestProperties.setAttribute("exportFilename", "export");
  
```
    In case you do not provide a filename for your export, the system will assign the default filename "export".
    Requires the Smart GWT server framework, but does not require use of server-based databinding - no .ds.xml files need to exist.
    You can also inject a small amount of CSS from the browser via DSRequest.exportCSS - this is intended primarily for switching the page size on the fly, for exceptionally wide or tall exports.
    Parameters:
    
    canvas - Canvas or canvas list that has exportable widgets, or an HTML fragment derived from getPrintHTML()
    
    See Also:
    
    HTMLString
  - exportContent
```
public static void exportContent(Canvas canvas,
                                 DSRequest requestProperties)
```
    Exports the printable representation of a set of widgets as a .pdf that is then downloaded to the user (triggering the "Save As.." dialog).
    As with other exports, the resulting file can be saved to the server filesystem instead of, or in addition to being downloaded to the user. See server-side docs for com.isomorphic.contentexport.PdfExport for more details on server-side processing and code samples for redirecting PDF output to a file or in-memory buffer, as well as instructions for adding additional stylesheets.
    You can either pass any Canvas to exportContent, or you can pass HTML that you have retrieved by calling Canvas.getPrintHTML(). When calling getPrintHTML() to retrieve HTML for use with exportContent(), you must pass the PrintProperties.printForExport or DrawPane and FacetChart instances will not export properly.
    You can use a custom skin when exporting your HTML content. To use a custom skin, add a line to server.properties:
```
    skin.{skinName}.location: custom/skin
  
```
    Where {skinName} is the name of your custom skin, and the value is the path to your skin resources from the application webroot.
    Also, you can set the filename of the export via DSRequest.exportFilename. For example:
```
  DSRequest requestProperties = new DSRequest();
  requestProperties.setAttribute("exportFilename", "export");
  
```
    In case you do not provide a filename for your export, the system will assign the default filename "export".
    Requires the Smart GWT server framework, but does not require use of server-based databinding - no .ds.xml files need to exist.
    You can also inject a small amount of CSS from the browser via DSRequest.exportCSS - this is intended primarily for switching the page size on the fly, for exceptionally wide or tall exports.
    Parameters:
    
    canvas - Canvas or canvas list that has exportable widgets, or an HTML fragment derived from getPrintHTML()
    
    requestProperties - Request properties for the export to pdf object
  - getQueueTransactionId
```
public static java.lang.Integer getQueueTransactionId()
```
    Returns the id of the current transaction (a queue of requests).
    This method will return null if no requests are currently queued, even if startQueue() has been called.
    
    Returns:
    
    the transactionNum of the current transaction, or null
  - setHandleErrorCallback
```
public static void setHandleErrorCallback(HandleErrorCallback callback)
```
    handleError() will be called if RPCResponse.status is negative and RPCRequest.willHandleError was not set. It is called for both DSResponses and RPCResponses that have a non-success status. You can check whether the response is a DSResponse by checking response.isDSResponse.
    By default handleError() always logs a warning. In addition, if response.data was set to a String, a warning dialog will be shown to the user with response.data as the message, which allows the server to send user error messages back without writing custom client-side error handling.
    To do custom error handling that is specific to a particular component or type of request, set RPCRequest.willHandleError and deal with errors in the rpcRequest.callback. To change the default system-wide error handling, install a HandleErrorCallback with this method. To invoke the default error handling in your new handler, you can simply call the method runDefaultErrorHandling().
    If you're using the xmlHttpRequest RPCRequest.transport, you can access the HTTP status code of the response (eg 404 Not Found or 500 Server Error) as RPCResponse.httpResponseCode.
    For very advanced usage, the response.xmlHttpRequest contains the native XMLHttpRequest object used to make the request. This can be accessed via DSResponse.getAttributeAsJavaScriptObject(). Accessing this object is subject to possible cross-platform bugs and inconsistencies, and Isomorphic recommends that you wrap any access to the XMLHttpRequest object in a try/catch block because some browsers may throw exceptions when certain attributes of this object are accessed. For example, if you try to access XMLHttpRequest.status (for the HTTP status code) when the network cable is unpluged in Windows, you'll get an Exception in Firefox.
    See the overview of error handling for additional guidance.
    
    Parameters:
    
    callback - HandleErrorCallback the callback to set.
    
    See Also:
    
    ErrorEvent, HandleTransportErrorCallback.handleTransportError(int, int, int, java.lang.String), runDefaultErrorHandling(com.smartgwt.client.data.DSResponse, com.smartgwt.client.data.DSRequest)
  - hasCurrentTransactionQueued
```
public static java.lang.Boolean hasCurrentTransactionQueued()
```
    Returns true if there is a current transaction (queue of requests)
    This method will return false if no requests are currently queued, even if startQueue() has been called.
    
    Returns:
    
    true if there is a current transaction
  - isScreenCached
```
public static void isScreenCached(java.lang.String screenName)
```
    Returns true if a screen with the given name has already been cached by a call to cacheScreens() (or loadProject()), false otherwise.
    
    Parameters:
    
    screenName - name of the screen
  - loadProject
```
public static void loadProject(java.lang.String projectNames,
                               Function callback,
                               LoadProjectSettings settings)
```
    Loads projects using the ProjectLoaderServlet, reachable at projectLoaderURL, and fires the given callback after screens have been cached.
    
    Parameters:
    
    projectNames - Comma separated string containing the names of project/s to load.
    
    callback - callback for notification of completion of project/s loaded and screens cached.
    
    settings - Settings applicable to the loadProject operation.
  - setLoginRequiredCallback
```
public static void setLoginRequiredCallback(LoginRequiredCallback callback)
```
    Called when a session timeout is encountered while trying to do a background RPC. See Relogin.
    The transaction with the passed transactionId is suspended, and should either be cleared or resent after the user has been re-authenticated.
    The rpcRequest parameter can be used to determine whether the suspended transaction can simply be dropped (eg, it's periodic polling request).
    The rpcResponse parameter has rpcResponse.data set to the raw text of the response that triggered loginRequired(). Some very advanced relogin strategies may need to inspect the raw response to get information needed for re-authentication.
    
    Parameters:
    
    callback - LoginRequiredCallback the callback to set.
  - setQueueSentCallback
```
public static void setQueueSentCallback(QueueSentCallback callback)
```
    This method is called by the RPCManager every time it sends a queue of requests to the server (note that if you are not using queuing, the system simply sends queues containing just one request, so this API is valid regardless).
    There is no default implementation of this method; it is simply an override point. It is intended to be used by user code that needs to be notified when Smart GWT sends requests to the server. Note that the list of RPCRequests passed to this method is strictly read-only.
    
    Parameters:
    
    callback - QueueSentCallback the callback to set.
  - requestsArePending
```
public static java.lang.Boolean requestsArePending()
```
    Returns whether there are any pending RPC requests.
    
    Returns:
    
    true if one or more RPC requests are pending, false otherwise.
  - resendTransaction
```
public static void resendTransaction()
```
    Resend a suspended transaction to the server. See suspendTransaction() for context.
    Note that the transaction must have been previously suspended, and in particular suspended validly according to the rules described in the docs for suspendTransaction(), or undefined results will occur.
    You can resend all suspended transactions by calling resendTransaction() with no arguments.
  - resendTransaction
```
public static void resendTransaction(int transactionNum)
```
    Resend a suspended transaction to the server. See suspendTransaction() for context.
    Note that the transaction must have been previously suspended, and in particular suspended validly according to the rules described in the docs for suspendTransaction(), or undefined results will occur.
    You can resend all suspended transactions by calling resendTransaction() with no arguments.
    
    Parameters:
    
    transactionNum - id of the transaction to be re-sent, or null to resend all suspended transactions
  - runDefaultErrorHandling
```
public static void runDefaultErrorHandling(DSResponse response,
                                           DSRequest request)
```
    Runs the default error handling normally performed by HandleErrorCallback.handleError(). May be called from a custom handler to achieve the default behavior if one has been installed.
    
    Parameters:
    
    response - response the response
    
    request - request the request
    
    See Also:
    
    HandleErrorCallback.handleError(com.smartgwt.client.data.DSResponse, com.smartgwt.client.data.DSRequest)
  - sendQueue
```
public static void sendQueue()
```
    Send all currently queued requests to the server. You need only call this method if you are using queuing otherwise your requests are synchronously submitted to the server.
    This method will do nothing and the callback will not be called if no requests have actually been queued. You can detect whether the queue is empty by calling getQueueTransactionId().
    NOTE: if you aren't the caller who first enables queuing (startQueue() returns true), you should in general avoid calling sendQueue(), because whoever was first to enable queuing may have more requests to add to the same queue.
    See startQueue() for more information about queuing.
    
    See Also:
    
    send(java.lang.String, com.smartgwt.client.rpc.RPCCallback, com.smartgwt.client.rpc.RPCRequest), sendRequest(com.smartgwt.client.rpc.RPCRequest), startQueue()
  - sendQueue
```
public static void sendQueue(RPCQueueCallback callback)
```
    Send all currently queued requests to the server. You need only call this method if you are using queuing otherwise your requests are synchronously submitted to the server.
    This method will do nothing and the callback will not be called if no requests have actually been queued. You can detect whether the queue is empty by calling getQueueTransactionId().
    NOTE: if you aren't the caller who first enables queuing (startQueue() returns true), you should in general avoid calling sendQueue(), because whoever was first to enable queuing may have more requests to add to the same queue.
    See startQueue() for more information about queuing.
    
    Parameters:
    
    callback - Callback to fire when the queued operations complete. Callback will be fired with 1 parameter: responses an array of DSResponse or RPCResponse objects that were part of the transaction fired by this method.
    
    See Also:
    
    send(java.lang.String, com.smartgwt.client.rpc.RPCCallback, com.smartgwt.client.rpc.RPCRequest), sendRequest(com.smartgwt.client.rpc.RPCRequest), startQueue()
  - startQueue
```
public static boolean startQueue()
```
    Start queuing DSRequests and RPCRequests system-wide, for later sending when RPCManager.sendQueue() is called, at which time all queued requests will be sent as a single, combined HTTP request.
    Combining requests via queuing:
    - allows the server to implement transactional saving when multiple records are affected by actions in the UI
    - can reduce overhead by combining related requests, avoiding the use of multiple network connections, redundant authentication checks, and other redundant resource allocations that would otherwise happen if requests were processed separately
    - can simplify application logic that otherwise has to deal with multiple outstanding server requests that might complete in any order
    Queuing is used automatically by many, many framework features, including multi-row grid editing (Grid Mass Editing), multi-row drag & drop, data paging for large trees, "serverCustom" validators, Master-Detail saves, OLAP / datacube functionalty, and many others.
    Queuing also has subtler architectural benefits in terms of building reusable services - see the QuickStart Guide sections on Queuing for details.
    For all the reasons given above, it's extremely important to use DataSources that can support queuing. Queuing is automatically supported when using server-based DataSources with the Smart GWT Server Framework, and is supported by RestDataSource.
    Order of Execution
    When the Smart GWT Server framework receives a queued request, it will process all requests, in order, in a single thread, before any response is sent to the client. All client-side actions related to queued requests, such as callbacks firing on completion, likewise happen in queue order, after all server-side processing has taken place.
    Therefore when using queuing you can use the callback argument of sendQueue() to detect that all operations have completed, which is much simpler than the logic needed to track multiple asynchronous operations and wait for all to complete.
    Nested Queuing
    In some cases you may wish to combine requests being sent by application logic with queued requests automatically sent by components. For example, you may want to call ListGrid.saveAllEdits() but also add an additional request to the same queue.
    To do this, just call startQueue() before saveAllEdits() (or whatever other API would also normally perform a queued request), then call sendQueue(). Framework features that use queuing will automatically notice that you have already started a queue, and will not automatically call sendQueue() in this case. You can implement the same behavior in your own reusable components by checking the return value of startQueue(), which tells you whether queuing is already active.
    Requests that can't be queued
    When using queuing, all requests in a given queue must go to the same RPCRequest.actionURL and use the same transport (XMLHttp or frames). If a request specifies a different actionURL or transport than that of the requests currently on the queue, it will be sent to the server separately, ahead of the queue, and a warning will be logged to the Developer Console.
    Due to browser security restrictions, at most one request with a file\n upload can be sent in a queue. If you attempt to add another, the existing queue will be sent immediately, logging a warning, and queueing restarted for the new request.
    Note that whenever requests are not sent in a single queue, order is not guaranteed, and the callback provided to sendQueue() at the end of your transaction may fire before requests not sent in the final queue have completed.
    Implementing your own Queuing
    If you are in the rare situation that:
    - you can't use the Smart GWT Server framework
    - the server you are integrating with some pre-existing support for combining operations in a flexible way, similar to queuing
    - you are totally unable to implement the RestDataSource protocol for this server, even through approaches such as adding it as an additional service while leaving the original services unchanged, or going through an intermediate server
    .. then you can implement a crude version of the built-in queuing feature by using dataProtocol:"clientCustom" to avoid HTTP requests being immediately sent when a DataSource executes. In outline:
    - create an API similar to startQueue() for managing a global setting reflecting whether your special queuing system is active. Your DataSources should check for this global setting in DataSource.transformRequest(), and, if queuing is active, store the request you received in DataSource.transformRequest() in memory, for example in an Array
    - implement your own equivalent of RPCManager.sendQueue() which sends an HTTP request representing your combined requests, then once you receive your combined response, call DataSource.processResponse() for each request.
    Note that attempting to integrate with RPCManager's queuing system doesn't really make sense - RPCManager won't be aware of your separate, special queue of requests, so will reject calls to sendQueue() since RPCManager's queue is empty. Similarly, enabling queuing on RPCManager may cause inadvertent queuing of unrelated requests you did not intend to queue. Maintaining your own separate notion of whether queuing is active is simpler and less error prone.
    Returns:
    
    whether queuing was already enabled before we called.
    
    See Also:
    
    sendQueue()
  - startQueue
```
public static boolean startQueue(boolean shouldQueue)
```
    Start queuing DSRequests and RPCRequests system-wide, for later sending when RPCManager.sendQueue() is called, at which time all queued requests will be sent as a single, combined HTTP request.
    Combining requests via queuing:
    - allows the server to implement transactional saving when multiple records are affected by actions in the UI
    - can reduce overhead by combining related requests, avoiding the use of multiple network connections, redundant authentication checks, and other redundant resource allocations that would otherwise happen if requests were processed separately
    - can simplify application logic that otherwise has to deal with multiple outstanding server requests that might complete in any order
    Queuing is used automatically by many, many framework features, including multi-row grid editing (Grid Mass Editing), multi-row drag & drop, data paging for large trees, "serverCustom" validators, Master-Detail saves, OLAP / datacube functionalty, and many others.
    Queuing also has subtler architectural benefits in terms of building reusable services - see the QuickStart Guide sections on Queuing for details.
    For all the reasons given above, it's extremely important to use DataSources that can support queuing. Queuing is automatically supported when using server-based DataSources with the Smart GWT Server Framework, and is supported by RestDataSource.
    Order of Execution
    When the Smart GWT Server framework receives a queued request, it will process all requests, in order, in a single thread, before any response is sent to the client. All client-side actions related to queued requests, such as callbacks firing on completion, likewise happen in queue order, after all server-side processing has taken place.
    Therefore when using queuing you can use the callback argument of sendQueue() to detect that all operations have completed, which is much simpler than the logic needed to track multiple asynchronous operations and wait for all to complete.
    Nested Queuing
    In some cases you may wish to combine requests being sent by application logic with queued requests automatically sent by components. For example, you may want to call ListGrid.saveAllEdits() but also add an additional request to the same queue.
    To do this, just call startQueue() before saveAllEdits() (or whatever other API would also normally perform a queued request), then call sendQueue(). Framework features that use queuing will automatically notice that you have already started a queue, and will not automatically call sendQueue() in this case. You can implement the same behavior in your own reusable components by checking the return value of startQueue(), which tells you whether queuing is already active.
    Requests that can't be queued
    When using queuing, all requests in a given queue must go to the same RPCRequest.actionURL and use the same transport (XMLHttp or frames). If a request specifies a different actionURL or transport than that of the requests currently on the queue, it will be sent to the server separately, ahead of the queue, and a warning will be logged to the Developer Console.
    Due to browser security restrictions, at most one request with a file\n upload can be sent in a queue. If you attempt to add another, the existing queue will be sent immediately, logging a warning, and queueing restarted for the new request.
    Note that whenever requests are not sent in a single queue, order is not guaranteed, and the callback provided to sendQueue() at the end of your transaction may fire before requests not sent in the final queue have completed.
    Implementing your own Queuing
    If you are in the rare situation that:
    - you can't use the Smart GWT Server framework
    - the server you are integrating with some pre-existing support for combining operations in a flexible way, similar to queuing
    - you are totally unable to implement the RestDataSource protocol for this server, even through approaches such as adding it as an additional service while leaving the original services unchanged, or going through an intermediate server
    .. then you can implement a crude version of the built-in queuing feature by using dataProtocol:"clientCustom" to avoid HTTP requests being immediately sent when a DataSource executes. In outline:
    - create an API similar to startQueue() for managing a global setting reflecting whether your special queuing system is active. Your DataSources should check for this global setting in DataSource.transformRequest(), and, if queuing is active, store the request you received in DataSource.transformRequest() in memory, for example in an Array
    - implement your own equivalent of RPCManager.sendQueue() which sends an HTTP request representing your combined requests, then once you receive your combined response, call DataSource.processResponse() for each request.
    Note that attempting to integrate with RPCManager's queuing system doesn't really make sense - RPCManager won't be aware of your separate, special queue of requests, so will reject calls to sendQueue() since RPCManager's queue is empty. Similarly, enabling queuing on RPCManager may cause inadvertent queuing of unrelated requests you did not intend to queue. Maintaining your own separate notion of whether queuing is active is simpler and less error prone.
    Parameters:
    
    shouldQueue - whether queuing should be enabled, default true. Passing false will disable queuing but not send the queue yet, so that any queued requests will be sent along with the next send()/sendRequest()
    
    Returns:
    
    whether queuing was already enabled before we called.
    
    See Also:
    
    sendQueue()
  - transformRequest
```
public static java.lang.Object transformRequest(RPCRequest rpcRequest)
```
    Returns the data that should be sent to the actionURL.
    In a manner analogous to DataSource.transformRequest(), this method allows you to transform an RPCRequest, such as by adding HTTP headers, to ensure proper handling on the server.
    This is not an override point. See customizeTransforms(RequestTransformer).
    
    Parameters:
    
    rpcRequest - the RPCRequest being processed
    
    Returns:
    
    data to be sent to the actionURL
  - xmlHttpRequestAvailable
```
public static java.lang.Boolean xmlHttpRequestAvailable()
```
    Returns true if the XMLHttpRequest object is available, false otherwise. See PlatformDependencies for more information on when XMLHttpRequest parser may not available and what features are impacted as a result.
    
    Returns:
    
    true if XMLHttpRequest is available, false otherwise.
  - getMaxLoginAttemptsExceededMarker
```
public static void getMaxLoginAttemptsExceededMarker()
```
    Get the marker the system will look for in order to detect when the number of maximum logins was exceeded.
    
    See Also:
    
    com.smartgwt.client.rpc.RPCManager#setLoginRequiredMarker()
  - setMaxLoginAttemptsExceededMarker
```
public static java.lang.String setMaxLoginAttemptsExceededMarker(java.lang.String maxLoginAttemptsExceededMarker)
```
    Set the marker the system will look for in order to detect when the number of maximum logins was exceeded.
    
    Parameters:
    
    loginSuccessMarker - default value <SCRIPT>//'\"]]>>isc_maxLoginAttemptsExceeded
    
    See Also:
    
    com.smartgwt.client.rpc.RPCManager#setLoginRequiredMarker()
  - setDefaultTimeout
```
public static void setDefaultTimeout(double defaultTimeout)
```
    In milliseconds, how long the RPCManager waits for an RPC request to complete before returning an error. If set to zero, the RPCManager will not enforce a timeout, but note that most browsers enforce their own timeouts on HTTP requests.
    
    For the "xmlHttpRequest" transport, this timeout can only happen if the server actually fails to respond within the specified number of milliseconds. For the "hiddenFrames" transport, this timeout will occur for non-200 (HTTP_OK) responses.
    
    Parameters:
    
    defaultTimeout - the default value is 240000 [4 minutes]
  - setDefaultPrompt
```
public static void setDefaultPrompt(java.lang.String defaultPrompt)
```
    If showPrompt is enabled for a given transaction, this is the defaultPrompt to be shown to the user in a modal dialog while the transaction occurs. May be overridden at the request level via RPCRequest.prompt.
    More targeted default prompts are also supported for certain code-paths. See the following set of properties for details:
    - RPCManager.removeDataPrompt
    - RPCManager.saveDataPrompt
    - RPCManager.fetchDataPrompt
    Parameters:
    
    defaultPrompt - the default value is 'Contacting Server...'
  - setFetchDataPrompt
```
public static void setFetchDataPrompt(java.lang.String fetchDataPrompt)
```
    Default prompt displayed to the user while an operation is running to fetch data from the server. Displayed as a result of ListGrid.filterData(), ListGrid.fetchData() and ListGrid.clearCriteria() code paths.
    
    Parameters:
    
    fetchDataPrompt - defaults to "Finding Records that match your criteria..."
  - setRemoveDataPrompt
```
public static void setRemoveDataPrompt(java.lang.String removeDataPrompt)
```
    Default prompt displayed to user while an operation is running to remove data from the server. Displayed as a result of the ListGrid.removeSelectedData() code path.
    
    Parameters:
    
    removeDataPrompt - default value "Deleting Record(s)..."
  - setSaveDataPrompt
```
public static void setSaveDataPrompt(java.lang.String saveDataPrompt)
```
    Default prompt displayed to the user while an operation is running to save data to the server. Displayed as a result of the DynamicForm.saveData() code path.
    
    Parameters:
    
    saveDataPrompt - default value "Saving form..."
  - setPromptCursor
```
public static void setPromptCursor(java.lang.String promptCursor)
```
    Controls the default cursor shown when RPCManager.promptStyle is set to "cursor". Overridable by RPCRequest.promptCursor. In Safari, IE 5.5 and Firefox 1.0 the default value is "wait", on all other platforms it is "progress". The reason for this split is that the above-mentioned browsers do not support CSS2.1 - which is required for the "progress" cursor type.
    
    Parameters:
    
    promptCursor - default is browser dependent
  - setPromptStyle
```
public static void setPromptStyle(PromptStyle promptStyle)
```
    Controls the default prompt style. Overridable by RPCRequest.promptStyle.
    
    Parameters:
    
    promptStyle - default is PromptStyle.DIALOG
  - setUseCursorTracking
```
public static void setUseCursorTracking(boolean useCursorTracking)
```
    If true, an image is shown to the right of the cursor when RPCRequest.promptStyle is set to "cursor", otherwise the cursor itself is modified via css to the value of RPCRequest.promptCursor. The default is platform-dependent. In Safari, IE 5.5 and Firefox 1.0 the default is true, on all other platforms it is false. The reason for this split is that, the above browsers require that the cursor move before CSS settings are re-evaluated - this means the progress cursor can stick until the user moves the mouse.
    This value can be overridden on a per-request basis via RPCRequest.useCursorTracker.
    
    Parameters:
    
    useCursorTracking - default value is platform-dependent
  - cancelQueue
```
public static void cancelQueue(java.lang.String transactionNum)
```
    Deprecated. please use int methods when dealing with transaction number.
    
    Cancel a queue of requests (also called a transaction).
    If a transactionId is passed, that transaction will be cancelled, otherwise, the current (not yet sent) transaction is cancelled. You can retrieve the id of the current transaction, if there is one, by calling getCurrentTransactionId() before the transaction has been sent.
    Note that cancelQueue() calls clearTransaction() and attempts to abort the request. However, note also that whilst cancelling a transaction that has already been sent will not necessarily stop the HTTP request that has been issued - this is only possible on some browsers and with some transports - it will reliably cause Smart GWT to ignore any response returned by the server and not fire any callbacks that have been passed in.
    
    Parameters:
    
    transactionNum - transactionId of the queue.
  - clearTransaction
```
public static void clearTransaction(java.lang.String transactionNum)
```
    Deprecated. please use int methods when dealing with transaction number.
    
    Erase all client-side record of a transaction, such that any response from the server will be ignored.
    A transaction means a batch of one or more RPCRequests that have already been sent to the server via RPCManager.sendQueue.
    You can retrieve the id of the current transaction, if there is one, by getCurrentTransactionId() before the transaction is sent.
    
    Parameters:
    
    transactionNum - id of the transaction to be cleared
  - resendTransaction
```
public static void resendTransaction(java.lang.String transactionNum)
```
    Deprecated. please use int methods when dealing with transaction number.
    
    Resend a suspended transaction to the server. See RPCManager.suspendTransaction for context.
    Note that the transaction must have been previously suspended, and in particular suspended validly according to the rules described in the docs for RPCManager.suspendTransaction, or undefined results will occur.
    You can resend all suspended transactions by calling RPCManager.resendTransaction with no arguments.
    
    Parameters:
    
    transactionNum - id of the transaction to be re-sent, or null to resend all suspended transactions
  - suspendTransaction
```
public static void suspendTransaction()
```
    Suspends the current transaction, such that all processing of the transaction is halted, any remaining callback in the transaction won't fire, and the transaction can never timeout.
    suspendTransaction() is typically used to handle total failures for an entire transaction, such as HTTP status 500, or session timeout resulting in com.smartgwt.client.rpc.RPCManager#loginRequired being called. In both cases the intent is to put the transaction on hold so that a transient problem can be resolved, and then the transaction can be re-sent successfully. By using suspendTransaction(), components that submitted requests never realize there was a transient failure, and so error handling logic does not have to be implemented in every component.
    Generally you can only validly suspend a transaction from either com.smartgwt.client.rpc.RPCManager#loginRequired or com.smartgwt.client.rpc.RPCManager#handleError, and in the case of handleError(), only when the first response in the transaction has an error. Suspending and re-sending a partially processed transaction means that some responses will be processed twice, with undefined results for requests issued automatically by UI components.
    A suspended transaction must ultimately be either cleared via clearTransaction(int) or re-sent via resendTransaction() or memory will be leaked.
  - suspendTransaction
```
public static void suspendTransaction(java.lang.String transactionID)
```
    Deprecated. please use int methods when dealing with transaction number.
    
    Suspends the current transaction, such that all processing of the transaction is halted, any remaining callback in the transaction won't fire, and the transaction can never timeout.
    suspendTransaction() is typically used to handle total failures for an entire transaction, such as HTTP status 500, or session timeout resulting in com.smartgwt.client.rpc.RPCManager#loginRequired being called. In both cases the intent is to put the transaction on hold so that a transient problem can be resolved, and then the transaction can be re-sent successfully. By using suspendTransaction(), components that submitted requests never realize there was a transient failure, and so error handling logic does not have to be implemented in every component.
    Generally you can only validly suspend a transaction from either com.smartgwt.client.rpc.RPCManager#loginRequired or com.smartgwt.client.rpc.RPCManager#handleError, and in the case of handleError(), only when the first response in the transaction has an error. Suspending and re-sending a partially processed transaction means that some responses will be processed twice, with undefined results for requests issued automatically by UI components.
    A suspended transaction must ultimately be either cleared via clearTransaction(int) or re-sent via resendTransaction() or memory will be leaked.
    
    Parameters:
    
    transactionID - transaction to delay. Defaults to the current transaction if there is one
  - suspendTransaction
```
public static void suspendTransaction(int transactionID)
```
    Suspends the current transaction, such that all processing of the transaction is halted, any remaining callback in the transaction won't fire, and the transaction can never timeout.
    suspendTransaction() is typically used to handle total failures for an entire transaction, such as HTTP status 500, or session timeout resulting in com.smartgwt.client.rpc.RPCManager#loginRequired being called. In both cases the intent is to put the transaction on hold so that a transient problem can be resolved, and then the transaction can be re-sent successfully. By using suspendTransaction(), components that submitted requests never realize there was a transient failure, and so error handling logic does not have to be implemented in every component.
    Generally you can only validly suspend a transaction from either com.smartgwt.client.rpc.RPCManager#loginRequired or com.smartgwt.client.rpc.RPCManager#handleError, and in the case of handleError(), only when the first response in the transaction has an error. Suspending and re-sending a partially processed transaction means that some responses will be processed twice, with undefined results for requests issued automatically by UI components.
    A suspended transaction must ultimately be either cleared via clearTransaction(int) or re-sent via resendTransaction() or memory will be leaked.
    
    Parameters:
    
    transactionID - transaction to delay. Defaults to the current transaction if there is one
  - getCurrentTransactionId
```
public static java.lang.String getCurrentTransactionId()
```
    Deprecated. please use int methods when dealing with transaction number.
    
    Returns the id of the current transaction (a queue of requests).
    This method must be called after startQueue() has been called and at least one request has been issued.
    
    Returns:
    
    the transactionNum of the current transaction.
  - getCurrentTransactionIdAsInt
```
public static int getCurrentTransactionIdAsInt()
```
    Same as getQueueTransactionId() but returns -1 instead of null if there's no currently queued requests.
    
    Returns:
    
    the transactionNum of the current transaction.
  - sendProxied
```
public static void sendProxied(RPCRequest request,
                               RPCCallback callback)
```
    Send an HTTP request to a remote host, potentially through the HttpProxy servlet installed on the Smart GWT Server.
    This API allows contacting services which are hosted on servers other than the origin server if the HttpProxy servlet is enabled on the Smart GWT Server.
    The HttpProxy will be used if the actionURL starts with "http" and uses a hostname other than "localhost" or window.location.hostname, or if the port number differs, or if request.useHttpProxy is explicitly set. Otherwise the request goes to the origin server (the server that returned the current page).
    The RPCRequest properties that will be respected when relaying requests via the HttpProxy are: actionURL, httpMethod, params, contentType, httpHeaders, and data. In this case "data", if set, will be used as the request body for an HTTP POST.
    Higher-level APIs like DataSource or WebService call through this API, and so automatically use the HttpProxy if dataURL or webService.location is set to a foreign server.
    This API is only suitable for direct use when loading unstructured data that will not be shown in a DataBoundComponent. For a WSDL-described web service, use XMLTools.loadWSDL instead. For other web services, use a DataSource with dataURL, and use DataSource.transformRequest and DataSource.transformResponse as necessary to form requests for the service and transform responses for display.
    
    Parameters:
    
    request - rpcRequest to be routed through the HttpProxy
    
    callback - callback to invoke on RPC completion
  - sendRequest
```
public static void sendRequest(RPCRequest rpcRequestProperties)
```
    Send the passed RPCRequest to the server. If queuing is in effect, this queues the request instead.
    
    Parameters:
    
    rpcRequestProperties - RPCRequest to send to the server
  - sendRequest
```
public static void sendRequest(RPCRequest rpcRequestProperties,
                               RPCCallback callback)
```
    Send the passed RPCRequest to the server. If queuing is in effect, this queues the request instead.
    
    Parameters:
    
    rpcRequestProperties - RPCRequest to send to the server
    
    callback - callback to invoke on RPC completion
  - send
```
public static void send(java.lang.String data,
                        RPCCallback callback,
                        RPCRequest requestParams)
```
    This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
    
    Parameters:
    
    data - data to be passed to the server
    
    callback - callback to invoke on RPC completion
    
    requestParams - any additional properties you want to set - these will be applied to the RPCRequest object that will be auto-created for you.
  - send
```
public static void send(java.lang.String data,
                        RPCCallback callback,
                        java.util.Map requestParams)
```
    This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
    
    Parameters:
    
    data - data to be passed to the server
    
    callback - callback to invoke on RPC completion
    
    requestParams - any additional properties you want to set - these will be applied to the RPCRequest object that will be auto-created for you.
  - send
```
public static void send(com.google.gwt.core.client.JavaScriptObject data,
                        RPCCallback callback,
                        RPCRequest requestParams)
```
    This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
    
    Parameters:
    
    data - data to be passed to the server
    
    callback - callback to invoke on RPC completion
    
    requestParams - any additional properties you want to set - these will be applied to the RPCRequest object that will be auto-created for you.
  - send
```
public static void send(com.google.gwt.core.client.JavaScriptObject data,
                        RPCCallback callback,
                        java.util.Map requestParams)
```
    This method is a convenience wrapper on RPCManager.sendRequest() - it calls through to sendRequest().
    
    Parameters:
    
    data - data to be passed to the server
    
    callback - callback to invoke on RPC completion
    
    requestParams - any additional properties you want to set - these will be applied to the RPCRequest object that will be auto-created for you.
  - loadScreen
```
public static void loadScreen(java.lang.String screenName,
                              LoadScreenCallback callback)
```
    Loads a screen saved in Component XML format. See loadScreen(String, LoadScreenCallback, String[], String, RPCRequest)
    
    Parameters:
    
    screenName - name of the screen to load
    
    callback - callback for notification of screen being loaded
  - loadScreen
```
public static void loadScreen(java.lang.String screenName,
                              LoadScreenCallback callback,
                              java.lang.String[] globals)
```
    Loads a screen saved in Component XML format. See loadScreen(String, LoadScreenCallback, String[], String, RPCRequest)
    
    Parameters:
    
    screenName - name of the screen to load
    
    callback - callback for notification of screen being loaded
    
    globals - widgets to allow to take their global IDs
  - loadScreen
```
public static void loadScreen(java.lang.String screenName,
                              LoadScreenCallback callback,
                              java.lang.String[] globals,
                              RPCRequest requestProperties)
```
    Loads a screen saved in Component XML format. See loadScreen(String, LoadScreenCallback, String[], String, RPCRequest)
    
    Parameters:
    
    screenName - name of the screen to load
    
    callback - callback for notification of screen being loaded
    
    globals - widgets to allow to take their global IDs
    
    requestProperties - optional properties for the request
  - loadScreen
```
public static void loadScreen(java.lang.String screenName,
                              LoadScreenCallback callback,
                              java.lang.String[] globals,
                              java.lang.String locale,
                              RPCRequest requestProperties)
```
    Loads a screen saved in Component XML format, using the ScreenLoaderServlet.
    The ScreenLoaderServlet will look for a file named screenName.ui.xml in the directory given by the "project.ui" setting, which defaults webroot/shared/ui and can be configured in server.properties.
    The screen provided by the callback will be the outermost component if your loaded screen consists of a hierarchy of widgets all contained under one parent (which is true of any screens created in Visual Builder).
    If you have multiple widget hierarchies in your screen, the screen returned will be the last top-level component created.
    By default, components in the loaded screens that have global IDs will not actually be allowed to take those global IDs - instead, only widgets that have one of the global IDs passed as the globals parameter will actually receive their global IDs. To override this behavior, pass an array containing the special value ALL_GLOBALS for the globals parameter.
    When globals are being suppressed, the screen available in the callback will provide access to widgets that did not receive their global IDs via Canvas.getByLocalId(String), and the suppressedGlobals available in the callback will be a mapping from suppressed global ID to the widget or other component that would have used that global ID if globals were not suppressed.
    To load multiple screens at once, use cacheScreens(String[], Function, String, RPCRequest) and createScreen(String, String[]) instead.
    Components in the screen will default to having com.smartgwt.client.widgets.Canvas#setAutoDraw(Boolean) set to false. This may be overridden by setting the RPCRequest.setSuppressAutoDraw(Boolean) attribute explicitly to false on the request properties object.
    You can optionally provide a locale name to use when resolving any i18n tags in the screen's component XML. If you do not supply this, the locale will be derived from the servlet API, and so will generally be a locale appropriate to the client's operating system settings. Only provide a locale manually if you have a special requirement that requires the user's operating system locale to be overridden in your application. If you provide a locale name, it should be of the form "xx" or "xx_YY", where "xx" is a valid language code and "YY" is a valid country code. For example, "fr" or "en_GB".
    This API assumes the ScreenLoaderServlet is installed at the default location - to use a different location, use the requestProperties parameter to specify a different URL via +link{rpcRequest.actionURL}. The requestProperties parameter can also be used to pass additional params to a custom ScreenLoaderServlet - see the "Dynamic Component XML" section of the Component XML overview.
    
    Parameters:
    
    screenName - name of the screen to load
    
    callback - callback for notification of screen being loaded
    
    globals - widgets to allow to take their global IDs
    
    locale - the name of a locale to use for resolving i18n tags in the component XML of the screen
    
    requestProperties - optional properties for the request
  - setAllowIE9Leak
```
public static void setAllowIE9Leak(boolean allowLeak)
```
    In Internet Explorer 9, when a string of JavaScript is evaluated via the native eval() function, objects created within that evaluation are not released from browser memory until the page is reloaded.
    SmartGWT uses the eval() function to evaluate JSON formatted responses to RPCRequests by default, making long running applications potentially susceptible to memory leaks over time.
    Setting this property to false enables a workaround suggested on the Microsoft Knowledge Base to avoid such memory leaks by evaluating script in a hidden iframe and periodically refresh that frame. However developers should be aware of the following limitation with this setting: attempting to access certain object types including Date or function objects generated from such an evaluation can subsequently lead to a JavaScript error with the message "Can't execute code from a freed script".
    This workaround therefore may not be suitable for all transactions or dataSources within a given application.
    This property may also be specified for specific +link{RPCRequest.allowIE9Leak,RPCRequests}.
    Note: This issue is discussed further in the online SmartGWT FAQ.
  - createScreen
```
public static Canvas createScreen(java.lang.String screenName,
                                  CreateScreenSettings globals)
```
    Creates a screen previously cached by a call to cacheScreens().
    As with loadScreen(), the default behavior is to prevent any global widget IDs from being established, the returned Canvas will be the outermost component of the screen, and that Canvas will provide access to other widgets in the screen via getByLocalId()
    Alternatively, as with loadScreen(), a list of IDs that should be allowed to become globals can be passed, allowing those widgets to be retrieved via a call to Canvas.getById() after the screen has been created.
    If you do not pass globals and avoid depending on global IDs within the screen definition itself (for example, by embedding JavaScript event handlers in the screen definition that use global IDs), you can create the same screen multiple times.
    Creating a screen may or may not cause it to draw, depending on current global autoDraw setting (isc.setAutoDraw()) and any autoDraw settings in the screen itself.
    Instead of globals, you may instead pass a substitution configuration to change what classes are used to construct widgets, or subsitute existing widgets for those to be constructed, by widget ID.
    
    Parameters:
    
    screenName - name of the screen to create
    
    globals - widgets to allow to take their global IDs, or a widget remap config
    
    Returns:
    
    last top-level widget in the screen definition
  - exportContent
```
public static void exportContent(Canvas[] components,
                                 DSRequest requestProperties)
```
    Converts printable HTML generated from live UI components into a .pdf and downloads it ("Save As.." dialog).
    For DrawPane and subclasses (e.g. FacetChart) to export properly, the canvas parameter must be the widget itself, not the HTML obtained with getPrintHTML() unless the PrintProperties passed to getPrintHTML() had printForExport:true.
    You can use a custom skin when exporting your HTML content. To use a custom skin, add a line to server.properties:
```
    skin.{skinName}.location: custom/skin
  
```
    Where {skinName} is the name of your custom skin, and the value is the path to your skin resources from the application webroot.
    Requires the Smart GWT server framework, but does not require use of server-based databinding - no .ds.xml files need to exist.
    See server-side docs for com.isomorphic.contentexport.PdfExport for more details on server-side processing and code samples for redirecting PDF output to a file or in-memory buffer, as well as instructions for adding additional stylesheets.
    Parameters:
    
    components - Array of canvases that have exportable widgets.
    
    requestProperties - Request properties for the export to pdf object
  - exportContent
```
public static void exportContent(java.lang.String htmlFragment,
                                 DSRequest requestProperties)
```
    Converts printable HTML generated from live UI components into a .pdf and downloads it ("Save As.." dialog).
    For DrawPane and subclasses (e.g. FacetChart) to export properly, the canvas parameter must be the widget itself, not the HTML obtained with getPrintHTML() unless the PrintProperties passed to getPrintHTML() had printForExport:true.
    You can use a custom skin when exporting your HTML content. To use a custom skin, add a line to server.properties:
```
    skin.{skinName}.location: custom/skin
  
```
    Where {skinName} is the name of your custom skin, and the value is the path to your skin resources from the application webroot.
    Requires the Smart GWT server framework, but does not require use of server-based databinding - no .ds.xml files need to exist.
    See server-side docs for com.isomorphic.contentexport.PdfExport for more details on server-side processing and code samples for redirecting PDF output to a file or in-memory buffer, as well as instructions for adding additional stylesheets.
    Parameters:
    
    htmlFragment - HTML fragment derived from getPrintHTML(). See HTMLString.
    
    requestProperties - Request properties for the export to pdf object
  - exportImage
```
public static void exportImage(java.lang.String svgString)
```
  - exportImage
```
public static void exportImage(java.lang.String svgString,
                               DSRequest requestProperties)
```
  - exportImage
```
public static void exportImage(java.lang.String svgString,
                               DSRequest requestProperties,
                               ExportImageCallback callback)
```
    Converts an SVG string to one of several possible image formats, and can either initiate a download or return the base64-encoded image data. Control the image format via DSRequest.exportImageFormat.
    Default is to download the image (triggering the browser's save dialog). DSRequest.exportFilename can be used to control the default filename provided in the save dialog.
    To instead return the data as a normal DSResponse, set exportDisplay of requestProperties to ExportDisplay.RETURN. In this case the data is always base64 encoded.
    Requires the SmartClient server framework, with the same set of required .jars as are required for PDF export of charts in legacy IE.
    See also DrawPane.getSvgString() and DrawPane.getDataURL().
    
    Parameters:
    
    svgString - XML string containing SVG data
    
    requestProperties - request properties controlling options for export
    
    callback - optional callback when using exportDisplay:"return". Does not fire for other exportDisplay modes.
  - setHandleTransportErrorCallback
```
public static void setHandleTransportErrorCallback(HandleTransportErrorCallback callback)
```
    Sets callback to handle server error responses for submitted transactions. When the server responds to a submitted transaction with an HTTP error code this method will be called before any individual response callbacks are fired, regardless of whether RPCRequest.willHandleError was specified on the submitted request[s].
    This provides the developer with an opportunity to handle a server error by (for example) suspending and resubmitting the transaction before any other handling occurs.
    The default implementation takes no action - by default transport errors are handled via handleError(), or by the standard request callback methods, depending on request.willHandleError. To perform custom handing for transport errors, use this method to install a HandleTransportErrorCallback.
    See cancelDefaultErrorHandling() for details on how to stop the default error handling or current error handler if it interferes with what you're trying to do in the HandleTransportErrorCallback passed to this method.
    Note: This method only applies to operations submitted via XMLHttpRequest - it is not possible to provide similar error handling for other transports.
    See this separate article on error handling for an overview.
    
    Parameters:
    
    callback - HandleTransportErrorCallback the callback to set.
    
    See Also:
    
    HandleErrorCallback.handleError(com.smartgwt.client.data.DSResponse, com.smartgwt.client.data.DSRequest)
  - cancelDefaultErrorHandling
```
public static void cancelDefaultErrorHandling()
```
    Cancels default error handling for all DSResponses in the current transaction, ensuring that the default error handling or current error handler is not called for any of them. This method is intended to be called inside a HandleTransportErrorCallback, to prevent any potential interference from the default handling.
  - customizeTransforms
```
public static void customizeTransforms(RequestTransformer requestTransformer)
```
    Apply the specified RequestTransformer to override the default behavior of transformRequest(RPCRequest).
    
    Parameters:
    
    requestTransformer - the request transformer.

Class RPCManager

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ALL_GLOBALS

Constructor Detail

RPCManager

Method Detail

setActionURL

getActionURL

setAllowCrossDomainCalls

setCredentialsURL

getCredentialsURL

setLoginRequiredMarker

getLoginRequiredMarker

setLoginStatusCodeMarker

getLoginStatusCodeMarker

setLoginSuccessMarker

getLoginSuccessMarker

setShowPrompt

setTimeoutErrorMessage

setUseHttpProxy

cacheScreens

cacheScreens

cacheScreens

cancelQueue

cancelQueue

clearTransaction

createScreen

createScreen

exportContent

exportContent

exportContent

exportContent

getQueueTransactionId

setHandleErrorCallback

hasCurrentTransactionQueued

isScreenCached

loadProject

setLoginRequiredCallback

setQueueSentCallback

requestsArePending

resendTransaction

resendTransaction

runDefaultErrorHandling

sendQueue

sendQueue

startQueue

startQueue

transformRequest

xmlHttpRequestAvailable

getMaxLoginAttemptsExceededMarker

setMaxLoginAttemptsExceededMarker

setDefaultTimeout

setDefaultPrompt

setFetchDataPrompt

setRemoveDataPrompt

setSaveDataPrompt

setPromptCursor

setPromptStyle

setUseCursorTracking

cancelQueue

clearTransaction

resendTransaction

suspendTransaction

suspendTransaction

suspendTransaction

getCurrentTransactionId

getCurrentTransactionIdAsInt

sendProxied

sendRequest

sendRequest

send

send

send

send

loadScreen

loadScreen