FIFE  2008.0
TiXmlHandle Class Reference

#include <tinyxml.h>

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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 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
 
TiXmlHandle Child (int index) const
 
TiXmlHandle ChildElement (const char *value, int index) const
 
TiXmlHandle ChildElement (int index) const
 
TiXmlNodeToNode () const
 
TiXmlElementToElement () const
 
TiXmlTextToText () const
 
TiXmlUnknownToUnknown () const
 
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 1634 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 1701 of file tinyxml.cpp.

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

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.

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

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.

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

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.

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

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

Definition at line 1699 of file tinyxml.h.

References ToElement().

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

Definition at line 1695 of file tinyxml.h.

References ToNode().

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

Definition at line 1703 of file tinyxml.h.

References ToText().

TiXmlElement* TiXmlHandle::ToElement ( ) const
inline

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

Definition at line 1684 of file tinyxml.h.

Referenced by Element().

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TiXmlNode* TiXmlHandle::ToNode ( ) const
inline

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

Definition at line 1681 of file tinyxml.h.

Referenced by Node().

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TiXmlText* TiXmlHandle::ToText ( ) const
inline

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

Definition at line 1687 of file tinyxml.h.

Referenced by Text().

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TiXmlUnknown* TiXmlHandle::ToUnknown ( ) const
inline

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

Definition at line 1690 of file tinyxml.h.

Referenced by Unknown().

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

Definition at line 1707 of file tinyxml.h.

References ToUnknown().


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