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tinyxml2::XMLHandle Class Reference

#include "tinyxml2.h"

Public Member Functions

 XMLHandle (XMLNode *node)
 Create a handle from any node (at any depth of the tree.) This can be a null pointer. More...
 
 XMLHandle (XMLNode &node)
 Create a handle from a node. More...
 
 XMLHandle (const XMLHandle &ref)
 Copy constructor. More...
 
XMLHandle FirstChild ()
 Get the first child of this handle. More...
 
XMLHandle FirstChildElement (const char *value=0)
 Get the first child element of this handle. More...
 
XMLHandle LastChild ()
 Get the last child of this handle. More...
 
XMLHandle LastChildElement (const char *_value=0)
 Get the last child element of this handle. More...
 
XMLHandle NextSibling ()
 Get the next sibling of this handle. More...
 
XMLHandle NextSiblingElement (const char *_value=0)
 Get the next sibling element of this handle. More...
 
XMLHandle & operator= (const XMLHandle &ref)
 Assignment. More...
 
XMLHandle PreviousSibling ()
 Get the previous sibling of this handle. More...
 
XMLHandle PreviousSiblingElement (const char *_value=0)
 Get the previous sibling element of this handle. More...
 
XMLDeclaration * ToDeclaration ()
 Safe cast to XMLDeclaration. This can return null. More...
 
XMLElement * ToElement ()
 Safe cast to XMLElement. This can return null. More...
 
XMLNode * ToNode ()
 Safe cast to XMLNode. This can return null. More...
 
XMLText * ToText ()
 Safe cast to XMLText. This can return null. More...
 
XMLUnknown * ToUnknown ()
 Safe cast to XMLUnknown. This can return null. More...
 

Detailed Description

A XMLHandle is a class that wraps a node pointer with null checks; this is an incredibly useful thing. Note that XMLHandle is not part of the TinyXML-2 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:

XMLElement* root = document.FirstChildElement( "Document" );
if ( root )
{
    XMLElement* element = root->FirstChildElement( "Element" );
    if ( element )
    {
        XMLElement* child = element->FirstChildElement( "Child" );
        if ( child )
        {
            XMLElement* child2 = child->NextSiblingElement( "Child" );
            if ( child2 )
            {
                // Finally do something useful.

And that doesn't even cover "else" cases. XMLHandle addresses the verbosity of such code. A XMLHandle checks for null pointers so it is perfectly safe and correct to use:

XMLHandle docHandle( &document );
XMLElement* child2 = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).FirstChild().NextSibling().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.

XMLHandle handleCopy = handle;

See also XMLConstHandle, which is the same as XMLHandle, but operates on const objects.

Constructor & Destructor Documentation

§ XMLHandle() [1/3]

tinyxml2::XMLHandle::XMLHandle ( XMLNode *  node)

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

§ XMLHandle() [2/3]

tinyxml2::XMLHandle::XMLHandle ( XMLNode &  node)

Create a handle from a node.

§ XMLHandle() [3/3]

tinyxml2::XMLHandle::XMLHandle ( const XMLHandle &  ref)

Copy constructor.

Member Function Documentation

§ FirstChild()

XMLHandle tinyxml2::XMLHandle::FirstChild ( )

Get the first child of this handle.

§ FirstChildElement()

XMLHandle tinyxml2::XMLHandle::FirstChildElement ( const char *  value = 0)

Get the first child element of this handle.

§ LastChild()

XMLHandle tinyxml2::XMLHandle::LastChild ( )

Get the last child of this handle.

§ LastChildElement()

XMLHandle tinyxml2::XMLHandle::LastChildElement ( const char *  _value = 0)

Get the last child element of this handle.

§ NextSibling()

XMLHandle tinyxml2::XMLHandle::NextSibling ( )

Get the next sibling of this handle.

§ NextSiblingElement()

XMLHandle tinyxml2::XMLHandle::NextSiblingElement ( const char *  _value = 0)

Get the next sibling element of this handle.

§ operator=()

XMLHandle& tinyxml2::XMLHandle::operator= ( const XMLHandle &  ref)

Assignment.

§ PreviousSibling()

XMLHandle tinyxml2::XMLHandle::PreviousSibling ( )

Get the previous sibling of this handle.

§ PreviousSiblingElement()

XMLHandle tinyxml2::XMLHandle::PreviousSiblingElement ( const char *  _value = 0)

Get the previous sibling element of this handle.

§ ToDeclaration()

XMLDeclaration* tinyxml2::XMLHandle::ToDeclaration ( )

Safe cast to XMLDeclaration. This can return null.

§ ToElement()

XMLElement* tinyxml2::XMLHandle::ToElement ( )

Safe cast to XMLElement. This can return null.

§ ToNode()

XMLNode* tinyxml2::XMLHandle::ToNode ( )

Safe cast to XMLNode. This can return null.

§ ToText()

XMLText* tinyxml2::XMLHandle::ToText ( )

Safe cast to XMLText. This can return null.

§ ToUnknown()

XMLUnknown* tinyxml2::XMLHandle::ToUnknown ( )

Safe cast to XMLUnknown. This can return null.


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