tinyxml2::XMLHandle Class Reference

#include <tinyxml2.h>

Collaboration diagram for tinyxml2::XMLHandle:

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

Private Attributes
XMLNode *	_node

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.FirstChildElement( "Document" ).FirstChildElement( "Element" ).FirstChildElement().NextSiblingElement();
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.

Definition at line 1788 of file tinyxml2.h.

Constructor & Destructor Documentation

XMLHandle() [1/3]

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

inline

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

Definition at line 1792 of file tinyxml2.h.

                                                                            {
        _node = node;
    }

XMLHandle() [2/3]

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

inline

Create a handle from a node.

Definition at line 1796 of file tinyxml2.h.

                                                                            {
        _node = &node;
    }

XMLHandle() [3/3]

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

inline

Copy constructor.

Definition at line 1800 of file tinyxml2.h.

                                                                            {
        _node = ref._node;
    }

Member Function Documentation

FirstChild()

XMLHandle tinyxml2::XMLHandle::FirstChild ( )

inline

Get the first child of this handle.

Definition at line 1810 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->FirstChild() : 0 );
    }

Referenced by Database::fromXml().

FirstChildElement()

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

inline

Get the first child element of this handle.

Definition at line 1814 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->FirstChildElement( name ) : 0 );
    }

Referenced by Database::fromXml(), ReadGeneric(), and ReadStringNode().

LastChild()

XMLHandle tinyxml2::XMLHandle::LastChild ( )

inline

Get the last child of this handle.

Definition at line 1818 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->LastChild() : 0 );
    }

LastChildElement()

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

inline

Get the last child element of this handle.

Definition at line 1822 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->LastChildElement( name ) : 0 );
    }

NextSibling()

XMLHandle tinyxml2::XMLHandle::NextSibling ( )

inline

Get the next sibling of this handle.

Definition at line 1834 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->NextSibling() : 0 );
    }

Referenced by Database::fromXml().

NextSiblingElement()

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

inline

Get the next sibling element of this handle.

Definition at line 1838 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->NextSiblingElement( name ) : 0 );
    }

operator=()

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

inline

Assignment.

Definition at line 1804 of file tinyxml2.h.

                                                                            {
        _node = ref._node;
        return *this;
    }

PreviousSibling()

XMLHandle tinyxml2::XMLHandle::PreviousSibling ( )

inline

Get the previous sibling of this handle.

Definition at line 1826 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->PreviousSibling() : 0 );
    }

PreviousSiblingElement()

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

inline

Get the previous sibling element of this handle.

Definition at line 1830 of file tinyxml2.h.

                                                                            {
        return XMLHandle( _node ? _node->PreviousSiblingElement( name ) : 0 );
    }

ToDeclaration()

XMLDeclaration * tinyxml2::XMLHandle::ToDeclaration ( )

inline

Safe cast to XMLDeclaration. This can return null.

Definition at line 1859 of file tinyxml2.h.

                                                {
        return ( ( _node == 0 ) ? 0 : _node->ToDeclaration() );
    }

ToElement()

XMLElement * tinyxml2::XMLHandle::ToElement ( )

inline

Safe cast to XMLElement. This can return null.

Definition at line 1847 of file tinyxml2.h.

                                                {
        return ( ( _node == 0 ) ? 0 : _node->ToElement() );
    }

Referenced by ReadStringNode().

ToNode()

XMLNode * tinyxml2::XMLHandle::ToNode ( )

inline

Safe cast to XMLNode. This can return null.

Definition at line 1843 of file tinyxml2.h.

                                                {
        return _node;
    }

Referenced by Database::fromXml().

ToText()

XMLText * tinyxml2::XMLHandle::ToText ( )

inline

Safe cast to XMLText. This can return null.

Definition at line 1851 of file tinyxml2.h.

                                                {
        return ( ( _node == 0 ) ? 0 : _node->ToText() );
    }

ToUnknown()

XMLUnknown * tinyxml2::XMLHandle::ToUnknown ( )

inline

Safe cast to XMLUnknown. This can return null.

Definition at line 1855 of file tinyxml2.h.

                                                {
        return ( ( _node == 0 ) ? 0 : _node->ToUnknown() );
    }

Member Data Documentation

_node

XMLNode* tinyxml2::XMLHandle::_node

private

Definition at line 1864 of file tinyxml2.h.

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

• sdk/tools/xml2sdb/tinyxml2.h