public interface StringMethods

String Methods Overview

A method flagged as a StringMethod can be specified as a String containing a valid JavaScript expression. This expression will automatically be converted to a function with a return value matching the value of the last statement. Providing a String is not required - you may use a real function instead.

For example - suppose you wanted to override the leafClick() method on the TreeGrid. Normally you would do so as follows:

  TreeGrid.create({
      ...
      leafClick : function(viewer, leaf, recordNum) { 
          if(leaf.name == 'zoo') { 
              alert(1); 
          } else {
              alert(2);
          }
      }
  });

Since leafClick is a StringMethod, however, you can shorten this to:

  TreeGrid.create({
      ...
      leafClick : "if(leaf.name == 'zoo') { alert(1); } else { alert(2); }";
  });

TypeScript Limitation

When using Smart GWT with TypeScript, string methods cannot be used because TypeScript's type system cannot express that a property accepts either a function OR a string in configuration objects, while still being callable as a function on component instances.

In TypeScript code, always use arrow functions instead of string methods:

  isc.TreeGrid.create({
      ...
      leafClick: (viewer, leaf, recordNum) => {
          if (leaf.name == 'zoo') { alert(1); } else { alert(2); }
      }
  });

Note that arrow functions capture the lexical this, so if your string method used this to reference the component, you should instead reference the component by its ID or via a variable.

Interface StringMethods

String Methods Overview