TiXmlHandle Class Reference

#include <tinyxml.h>

List of all members.

Public Member Functions

TiXmlHandle Child (int index) const
TiXmlHandle Child (const char *value, int index) const
TiXmlHandle ChildElement (int index) const
TiXmlHandle ChildElement (const char *value, int index) const
TiXmlElementElement () const
TiXmlHandle FirstChild (const char *value) const
 Return a handle to the first child node with the given name.
TiXmlHandle FirstChild () const
 Return a handle to the first child node.
TiXmlHandle FirstChildElement (const char *value) const
 Return a handle to the first child element with the given name.
TiXmlHandle FirstChildElement () const
 Return a handle to the first child element.
TiXmlNodeNode () const
TiXmlHandle operator= (const TiXmlHandle &ref)
TiXmlTextText () const
 TiXmlHandle (const TiXmlHandle &ref)
 Copy constructor.
 TiXmlHandle (TiXmlNode *_node)
 Create a handle from any node (at any depth of the tree.) This can be a null pointer.
TiXmlElementToElement () const
TiXmlNodeToNode () const
TiXmlTextToText () const
TiXmlUnknownToUnknown () const
TiXmlUnknownUnknown () const

Private Attributes

TiXmlNodenode

Detailed Description

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:

	<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
	}
	

Definition at line 1646 of file tinyxml.h.


Constructor & Destructor Documentation

TiXmlHandle::TiXmlHandle ( TiXmlNode _node  )  [inline]

Create a handle from any node (at any depth of the tree.) This can be a null pointer.

Definition at line 1650 of file tinyxml.h.

TiXmlHandle::TiXmlHandle ( const TiXmlHandle ref  )  [inline]

Copy constructor.

Definition at line 1652 of file tinyxml.h.


Member Function Documentation

TiXmlHandle TiXmlHandle::Child ( int  index  )  const

Return a handle to the "index" child. The first child is 0, the second 1, etc.

Definition at line 1682 of file tinyxml.cpp.

TiXmlHandle TiXmlHandle::Child ( const char *  value,
int  index 
) const

Return a handle to the "index" child with the given name. The first child is 0, the second 1, etc.

Definition at line 1701 of file tinyxml.cpp.

TiXmlHandle TiXmlHandle::ChildElement ( int  index  )  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.

Definition at line 1720 of file tinyxml.cpp.

TiXmlHandle TiXmlHandle::ChildElement ( const char *  value,
int  index 
) 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.

Definition at line 1739 of file tinyxml.cpp.

TiXmlElement* TiXmlHandle::Element (  )  const [inline]
Deprecated:
use ToElement. Return the handle as a TiXmlElement. This may return null.

Definition at line 1711 of file tinyxml.h.

TiXmlHandle TiXmlHandle::FirstChild ( const char *  value  )  const

Return a handle to the first child node with the given name.

Definition at line 1646 of file tinyxml.cpp.

TiXmlHandle TiXmlHandle::FirstChild (  )  const

Return a handle to the first child node.

Definition at line 1634 of file tinyxml.cpp.

TiXmlHandle TiXmlHandle::FirstChildElement ( const char *  value  )  const

Return a handle to the first child element with the given name.

Definition at line 1670 of file tinyxml.cpp.

TiXmlHandle TiXmlHandle::FirstChildElement (  )  const

Return a handle to the first child element.

Definition at line 1658 of file tinyxml.cpp.

TiXmlNode* TiXmlHandle::Node (  )  const [inline]
Deprecated:
use ToNode. Return the handle as a TiXmlNode. This may return null.

Definition at line 1707 of file tinyxml.h.

TiXmlHandle TiXmlHandle::operator= ( const TiXmlHandle ref  )  [inline]

Definition at line 1653 of file tinyxml.h.

TiXmlText* TiXmlHandle::Text (  )  const [inline]
Deprecated:
use ToText() Return the handle as a TiXmlText. This may return null.

Definition at line 1715 of file tinyxml.h.

TiXmlElement* TiXmlHandle::ToElement (  )  const [inline]

Return the handle as a TiXmlElement. This may return null.

Definition at line 1696 of file tinyxml.h.

TiXmlNode* TiXmlHandle::ToNode (  )  const [inline]

Return the handle as a TiXmlNode. This may return null.

Definition at line 1693 of file tinyxml.h.

TiXmlText* TiXmlHandle::ToText (  )  const [inline]

Return the handle as a TiXmlText. This may return null.

Definition at line 1699 of file tinyxml.h.

TiXmlUnknown* TiXmlHandle::ToUnknown (  )  const [inline]

Return the handle as a TiXmlUnknown. This may return null.

Definition at line 1702 of file tinyxml.h.

TiXmlUnknown* TiXmlHandle::Unknown (  )  const [inline]
Deprecated:
use ToUnknown() Return the handle as a TiXmlUnknown. This may return null.

Definition at line 1719 of file tinyxml.h.


Member Data Documentation

Definition at line 1722 of file tinyxml.h.


The documentation for this class was generated from the following files:
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rospack
Author(s): Morgan Quigley, Brian Gerkey
autogenerated on Fri Jan 11 09:35:30 2013