nux-1.16.0
TiXmlHandle Class Reference

A TiXmlHandle is a class that wraps a node pointer with null checks; this is an incredibly useful thing. More...

#include <NuxCore/TinyXML/tinyxml.h>

List of all members.

Public Member Functions

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

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 2025 of file tinyxml.h.


Member Function Documentation

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 1901 of file tinyxml.cpp.

References TiXmlNode::NextSibling(), and TiXmlHandle().

{
  if ( node )
  {
    int i;
    TiXmlNode *child = node->FirstChild ( value );

    for (       i = 0;
          child && i < count;
          child = child->NextSibling ( value ), ++i )
    {
      // nothing
    }

    if ( child )
      return TiXmlHandle ( child );
  }

  return TiXmlHandle ( 0 );
}
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 1879 of file tinyxml.cpp.

References TiXmlNode::NextSibling(), and TiXmlHandle().

{
  if ( node )
  {
    int i;
    TiXmlNode *child = node->FirstChild();

    for (       i = 0;
          child && i < count;
          child = child->NextSibling(), ++i )
    {
      // nothing
    }

    if ( child )
      return TiXmlHandle ( child );
  }

  return TiXmlHandle ( 0 );
}
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 1945 of file tinyxml.cpp.

References TiXmlNode::NextSiblingElement(), and TiXmlHandle().

{
  if ( node )
  {
    int i;
    TiXmlElement *child = node->FirstChildElement ( value );

    for (       i = 0;
          child && i < count;
          child = child->NextSiblingElement ( value ), ++i )
    {
      // nothing
    }

    if ( child )
      return TiXmlHandle ( child );
  }

  return TiXmlHandle ( 0 );
}
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 1923 of file tinyxml.cpp.

References TiXmlNode::NextSiblingElement(), and TiXmlHandle().

{
  if ( node )
  {
    int i;
    TiXmlElement *child = node->FirstChildElement();

    for (       i = 0;
          child && i < count;
          child = child->NextSiblingElement(), ++i )
    {
      // nothing
    }

    if ( child )
      return TiXmlHandle ( child );
  }

  return TiXmlHandle ( 0 );
}
TiXmlElement* TiXmlHandle::Element ( ) const [inline]
Deprecated:
use ToElement.

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

Definition at line 2127 of file tinyxml.h.

References ToElement().

  {
    return ToElement();
  }
TiXmlNode* TiXmlHandle::Node ( ) const [inline]
Deprecated:
use ToNode.

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

Definition at line 2120 of file tinyxml.h.

References ToNode().

  {
    return ToNode();
  }
TiXmlText* TiXmlHandle::Text ( ) const [inline]
Deprecated:
use ToText() Return the handle as a TiXmlText.

This may return null.

Definition at line 2134 of file tinyxml.h.

References ToText().

  {
    return ToText();
  }
TiXmlElement* TiXmlHandle::ToElement ( ) const [inline]

Return the handle as a TiXmlElement.

This may return null.

Definition at line 2100 of file tinyxml.h.

Referenced by Element().

  {
    return ( ( node && node->ToElement() ) ? node->ToElement() : 0 );
  }
TiXmlNode* TiXmlHandle::ToNode ( ) const [inline]

Return the handle as a TiXmlNode.

This may return null.

Definition at line 2094 of file tinyxml.h.

Referenced by Node().

  {
    return node;
  }
TiXmlText* TiXmlHandle::ToText ( ) const [inline]

Return the handle as a TiXmlText.

This may return null.

Definition at line 2106 of file tinyxml.h.

Referenced by Text().

  {
    return ( ( node && node->ToText() ) ? node->ToText() : 0 );
  }
TiXmlUnknown* TiXmlHandle::ToUnknown ( ) const [inline]

Return the handle as a TiXmlUnknown.

This may return null.

Definition at line 2112 of file tinyxml.h.

Referenced by Unknown().

  {
    return ( ( node && node->ToUnknown() ) ? node->ToUnknown() : 0 );
  }
TiXmlUnknown* TiXmlHandle::Unknown ( ) const [inline]
Deprecated:
use ToUnknown() Return the handle as a TiXmlUnknown.

This may return null.

Definition at line 2141 of file tinyxml.h.

References ToUnknown().

  {
    return ToUnknown();
  }

The documentation for this class was generated from the following files:
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