Chapter 3 DynaScript Predefined Objects

DOMCharacterData methods

The DOMCharacterData object inherits the methods from the DOMNode object, but it also has its own methods, which are discussed in this section.

appendData method

Syntax

DOMCharacterData.appendData( DOMString )

Description

Appends the string to the end of the character data represented by this object. DOMString is the string that is to be appended.

Example

Here is a very simple document:

<?xml version='1.0' encoding='ISO-8859-1' ?>
<Customer>
<FName>Jessie</FName>
<LName>Gagliardo</LName>
<Address><Street>2800 Park Avenue</Street>
<City>Hull</City>
<Region Type="Province">PQ</Region>
</Address></Customer>

This DynaScript fragment, which includes a Region element, checks whether the region is a province or a state, and appends a string indicating the country to the text element.

child = elemRegion.firstChild;
if( elemRegion.getAttribute( "Type" ) == "Province" ){
  child.appendData( ", Canada" );
} else {
  child.appendData( ", USA" );
}
document.writeln( child.data );

deleteData method

Syntax

DOMCharacterData.deleteData( offset, count )

Description

Removes a range of characters from the text represented by this object. The parameters are:

offset The offset from which to begin removing characters. Offset values begin at zero.
count The number of characters to delete. If the sum of offset and count exceeds the length of the text, all characters from the offset to the end of the data are deleted.

Example

This DynaScript statement deletes the first two characters from a text node.

if( elem.nodeType == 3 ) { // text node
  elem.deleteData( 0, 2 )
}

insertData method

Syntax

DOMCharacterData.insertData( offset, DOMString )

Description

Inserts a string at the specified character offset. The parameters are:

offset The character offset at which to insert. Offset values begin at zero.
DOMString The string to insert.

Example

This DynaScript fragment inserts a string at the beginning of a text node.

if( elem.nodeType == 3 ) { // text node
  elem.insertData( 0, "Region: " )
}

replaceData method

Syntax

DOMCharacterData.replaceData( offset, count, DOMString )

Description

Replaces the character starting at the specified character offset with the specified string. The parameters are:

offset The offset from which to start replacing. Offset values begin at zero.
count The number of characters to replace. If the sum of offset and count exceeds length, all characters to the end of the data are replaced.
DOMString The string with which the range is to be replaced.

Example

This DynaScript fragment replaces the third and fourth characters in a text node with the string "XXX".

if( elem.nodeType == 3 ) { // text node
  elem.replaceData( 3, 2, "XXX" )
}

substringData method

Syntax

DOMCharacterData.substringData( offset, count )

Description

Extracts a portion of the text represented by this object. The parameters are:

offset The offset from which to start extracting. Offset values begin at zero.
count The number of characters to extract.

Return

A string containing the extracted portion of the text.

Example

This DynaScript fragment writes out the characters from the fourth to the hundredth of all text nodes that are children of a Street element.

function SubstringDataCharacterData( domDoc ) {
  var elemlist = domDoc.getElementsByTagName( "Street" )
  for( iElem=0; iElem < elemlist.length; iElem++ ) {
    var elem = elemlist.item( iElem );
    var child = elem.firstChild;
    do {
      if( child.nodeType == 3 ){  // text node
        var svar = child.substringData( 3, 99 );
        document.writeln( "svar = " + svar );
      }
      child = child.nextSibling;
    } while ( child != null )
  }
}