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TiXmlHandle Class Reference
Detailed DescriptionA TiXmlHandle is a class that wraps a node pointer with null checks; this is an incredibly useful thing. Note that TiXmlHandle is not part of the TinyXml DOM structure. It is a separate utility class. Take an example: <Document>
<Element attributeA = "valueA">
<Child attributeB = "value1" />
<Child attributeB = "value2" />
</Element>
<Document>
Assuming you want the value of "attributeB" in the 2nd "Child" element, it's very easy to write a lot of code that looks like: TiXmlElement* root = document.FirstChildElement( "Document" );
if ( root )
{
TiXmlElement* element = root->FirstChildElement( "Element" );
if ( element )
{
TiXmlElement* child = element->FirstChildElement( "Child" );
if ( child )
{
TiXmlElement* child2 = child->NextSiblingElement( "Child" );
if ( child2 )
{
// Finally do something useful.
And that doesn't even cover "else" cases. TiXmlHandle addresses the verbosity of such code. A TiXmlHandle checks for null pointers so it is perfectly safe and correct to use: TiXmlHandle docHandle( &document );
TiXmlElement* child2 = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).Child( "Child", 1 ).ToElement();
if ( child2 )
{
// do something useful
Which is MUCH more concise and useful. It is also safe to copy handles - internally they are nothing more than node pointers. TiXmlHandle handleCopy = handle; What they should not be used for is iteration: int i=0;
while ( true )
{
TiXmlElement* child = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).Child( "Child", i ).ToElement();
if ( !child )
break;
// do something
++i;
}
It seems reasonable, but it is in fact two embedded while loops. The Child method is a linear walk to find the element, so this code would iterate much more than it needs to. Instead, prefer: TiXmlElement* child = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).FirstChild( "Child" ).ToElement();
for( child; child; child=child->NextSiblingElement() )
{
// do something
}
Constructor & Destructor Documentation
Create a handle from any node (at any depth of the tree.) This can be a null pointer.
Copy constructor. Member Function Documentation
Return a handle to the "index" child with the given name. The first child is 0, the second 1, etc.
Return a handle to the "index" child. The first child is 0, the second 1, etc.
Return a handle to the "index" child element with the given name. The first child element is 0, the second 1, etc. Note that only TiXmlElements are indexed: other types are not counted.
Return a handle to the "index" child element. The first child element is 0, the second 1, etc. Note that only TiXmlElements are indexed: other types are not counted.
References ChildElement(). Referenced by ChildElement().
References ToElement().
Return a handle to the first child node.
Return a handle to the first child node with the given name.
References FirstChild(). Referenced by FirstChild().
Return a handle to the first child element.
Return a handle to the first child element with the given name.
References FirstChildElement(). Referenced by FirstChildElement().
References ToNode().
References ToText().
Return the handle as a TiXmlElement. This may return null. References TiXmlNode::ToElement(). Referenced by Element().
Return the handle as a TiXmlText. This may return null. References TiXmlNode::ToText(). Referenced by Text().
Return the handle as a TiXmlUnknown. This may return null. References TiXmlNode::ToUnknown(). Referenced by Unknown().
References ToUnknown(). The documentation for this class was generated from the following file: |
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