com.smartgwt.client.docs.serverds

Class DSRequestModifier

java.lang.Object

com.smartgwt.client.docs.serverds.DSRequestModifier

public class DSRequestModifier
extends java.lang.Object

This class is not meant to be created and used, it is actually documentation of settings allowed in a DataSource descriptor (.ds.xml file). See com.smartgwt.client.docs.serverds for how to use this documentation.

Some elements of this feature are only available with Power or better licenses. See smartclient.com/product for details.

An object that modifies a dsRequest based on several available values, including preceding responses from the same queue. You provide a list of DSRequestModifiers as the OperationBinding.criteria or OperationBinding.values of an OperationBinding. The ability to modify a request based on responses to earlier requests in the same queue is called TransactionChaining.

A DSRequestModifier consists of a fieldName, usually a value and possibly an operator and start and/or end values (applicable to advanced criteria only). The value, start and end settings can be static, or - with Power or better licenses - they can be expressions in the Velocity template language, which will be resolved at runtime, immediately before the DSRequest is executed.

Field Summary

Fields

Modifier and Type	Field and Description
java.lang.String	end The value to use for the end of a range.
java.lang.String	fieldName The name of the field to add or replace on the DSRequest - whether this appears in the DSRequest's values or criteria depends on whether this is part of a OperationBinding.values or OperationBinding.criteria attribute.
java.lang.String	operator The name of the operator to apply when constructing criteria.
java.lang.String	start The value to use for the start of a range.
java.lang.String	value The value to assign to the field named by fieldName.

Constructor Summary

Constructors

Constructor and Description
DSRequestModifier()

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

end

public java.lang.String end

The value to use for the end of a range. This property only applies to criteria, and it only applies to operators of type "rangeCheck" - for example, the "between" operator. It is ignored if specified as part of a OperationBinding.values attribute, or for an inapplicable operator type.

The same rules apply to this attribute as apply to value, so you can use Velocity expressions if you have a Power or better license.

Default value is null

See Also:

TransactionChaining overview and related methods

value

public java.lang.String value

The value to assign to the field named by fieldName. This value can be static, and for Pro licenses that is the only option. With Power and better licenses, this value can be an expression in the Velocity template language. In this latter case, there are a number of context variables available to you:

• dsRequest. The DSRequest object being processed
• servletRequest. The HttpServletRequest object representing the queue of requests sent from the client
• responseData. The data member of a DSResponse object associated with an earlier DSRequest in the same queue

(Note that the standard Velocity context variables provided by Smart GWT Server are also available to you - see VelocitySupport).

The most interesting of these is the last. An example of when this might be useful would be a queued batch of "add" operations for an order header and its details - the detail additions need to know the unique primary key that was assigned to the order. This value will be in the response to the DSRequest that added the order header. See this example: Master/Detail Add Example.

You can obtain the responseData of prior responses using the following Velocity syntax:

$responseData.first.myField is the myField property of the first response in the queue
$responseData.first('order').myField is the myField property of the first response to an operation (any operation) on the "order" DataSource
$responseData.first('order', 'add').myField is the myField property of the first response to an "add" operation on the "order" DataSource

All of these syntactic variations are also available on the $responseData.last object - "last" here meaning the most recent response matching the DataSource and operation type (if applicable). Please see the server-side Javadoc for the com.isomorphic.velocity.ResponseDataHandler class.

Default value is null

See Also:

TransactionChaining overview and related methods

fieldName

public java.lang.String fieldName

The name of the field to add or replace on the DSRequest - whether this appears in the DSRequest's values or criteria depends on whether this is part of a OperationBinding.values or OperationBinding.criteria attribute.

Default value is null

operator

public java.lang.String operator

The name of the operator to apply when constructing criteria. This property only applies to criteria; it is ignored if specified as part of a OperationBinding.values attribute.

Default value is null

start

public java.lang.String start

The value to use for the start of a range. This property only applies to criteria, and it only applies to operators of type "rangeCheck" - for example, the "between" operator. It is ignored if specified as part of a OperationBinding.values attribute, or for an inapplicable operator type.

The same rules apply to this attribute as apply to value, so you can use Velocity expressions if you have a Power or better license.

Default value is null

See Also:

TransactionChaining overview and related methods

Constructor Detail

DSRequestModifier

public DSRequestModifier()