Recipe 20.4. Adding Text Nodes to an XML Object

Problem

You want to add text nodes to an XML object.

Solution

Use E4X syntax to create text nodes and add them to an XML tree. Use the appendChild( ), prependChild( ), insertChildAfter( ), and insertChildBefore( ) methods for more control over how the text nodes are added.

Discussion

Creating text nodes with E4X is, you guessed it, simple. The process is very similar to the method described in Recipe 20.3. As with elements, creating text nodes is just a matter of using the dot operator (.) to set a property on an XML instance to any value that can be converted to a string. Here is an example:

// Create an XML instance to work with
var example:XML = <example/>;

// Create a text node from a string
example.firstname = "Darron";

// Create a text node from a number
example.number = 24.9;

// Create a text node from a boolean
example.boolean = true;

// Create a text node from an array
example.abc = ["a", undefined, "b", "c", null, 7, false];

/* Displays:
<example>
  <firstname>Darron</firstname>
  <number>24.9</number>
  <boolean>true</boolean>
  <abc>a,,b,c,,7,false</abc>
</example>
*/
trace( example );

This example adds both text and element nodes to the example XML instance. The value on the righthand side of the assignment statement is converted into a string and becomes the text node. Then the property name is converted into an element node with the text node as a child, and the entire element node is appended to the XML instance.

For more control over where the text nodes are placed inside of element nodes, use either appendChild( ), prependChild( ), insertChildBefore( ), or insertChildAfter( ). These methods allow you to control precisely where the text node is inserted into the XML tree:

// Create an XML instance to work with
var example:XML = <example/>;

// Append a two element node containing a text node child 
// with value 2
example.appendChild( <two>2</two> );

// Prepend a one element node containing a text node child 
// with value "number 1"
example.prependChild( <one>"number 1"</one> );

// After the one element node, insert a text node with 
// value 1.5
example.insertChildAfter( example.one[0], 1.5 );

// Before the two element node, insert a part element node 
// containing a text node child with value 1.75
example.insertChildBefore( example.two[0], <part>1.75</part> );

/* Displays:
<example>
  <one>"number 1"</one>
  1.5
  <part>1.75</part>
  <two>2</two>
</example>
*/
trace( example );

In the preceding code example, a mixed element was created. A mixed element is one that contains not only a child text node or child elements, but both. The example element is mixed because it contains not only child elements (<one>, <part>, and <two>) but also a nested text node (with the value of 1.5). This is perfectly valid XML, and it demonstrates that an element can have more children than just a single text node.

See Also

Recipe 20.3