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A 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:
@verbatim
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:
@verbatim 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. @endverbatim
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:
@verbatim TiXmlHandle docHandle( &document ); TiXmlElement* child2 = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).Child( "Child", 1 ).Element(); if ( child2 ) { // do something useful @endverbatim
Which is MUCH more concise and useful.
It is also safe to copy handles - internally they are nothing more than node pointers. @verbatim TiXmlHandle handleCopy = handle; @endverbatim
What they should not be used for is iteration:
@verbatim int i=0; while ( true ) { TiXmlElement* child = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).Child( "Child", i ).Element(); if ( !child ) break; // do something ++i; } @endverbatim
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:
@verbatim TiXmlElement* child = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).FirstChild( "Child" ).Element();
for( child; child; child=child->NextSiblingElement() ) { // do something } @endverbatim
| TiXmlHandle ( TiXmlNode* _node )
| TiXmlHandle |
| TiXmlHandle ( const TiXmlHandle& ref )
| TiXmlHandle |
| TiXmlHandle operator= ( const TiXmlHandle& ref )
| operator= |
| TiXmlHandle FirstChild ()
| FirstChild |
[const]
| TiXmlHandle FirstChild ( const char * value )
| FirstChild |
[const]
| TiXmlHandle FirstChildElement ()
| FirstChildElement |
[const]
| TiXmlHandle FirstChildElement ( const char * value )
| FirstChildElement |
[const]
| TiXmlHandle Child ( const char* value, int index )
| Child |
[const]
Return a handle to the "index" child with the given name. The first child is 0, the second 1, etc.
| TiXmlHandle Child ( int index )
| Child |
[const]
Return a handle to the "index" child. The first child is 0, the second 1, etc.
| TiXmlHandle ChildElement ( const char* value, int index )
| ChildElement |
[const]
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.
| TiXmlHandle ChildElement ( int index )
| ChildElement |
[const]
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.
| TiXmlHandle FirstChild ( const std::string& _value )
| FirstChild |
[const]
| TiXmlHandle FirstChildElement ( const std::string& _value )
| FirstChildElement |
[const]
| TiXmlHandle Child ( const std::string& _value, int index )
| Child |
[const]
| TiXmlHandle ChildElement ( const std::string& _value, int index )
| ChildElement |
[const]
| TiXmlNode* Node ()
| Node |
[const]
| TiXmlElement* Element ()
| Element |
[const]
| TiXmlText* Text ()
| Text |
[const]
| TiXmlUnknown* Unknown ()
| Unknown |
[const]
| Generated by: paulc on bussard on Mon Mar 8 12:18:15 2010, using kdoc 2.0a54. |