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TiXmlHandle Class Reference

TinyXML class. See http://www.grinninglizard.com/tinyxml. More...

#include <tinyxml.h>

Public Member Functions

 TiXmlHandle (TiXmlNode *_node)
 Create a handle from any node (at any depth of the tree.) This can be a null pointer. More...
 
 TiXmlHandle (const TiXmlHandle &ref)
 Copy constructor. More...
 
TiXmlHandle operator= (const TiXmlHandle &ref)
 
TiXmlHandle FirstChild () const
 Return a handle to the first child node. More...
 
TiXmlHandle FirstChild (const char *value) const
 Return a handle to the first child node with the given name. More...
 
TiXmlHandle FirstChildElement () const
 Return a handle to the first child element. More...
 
TiXmlHandle FirstChildElement (const char *value) const
 Return a handle to the first child element with the given name. More...
 
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
 
TiXmlHandle FirstChild (const std::string &_value) const
 
TiXmlHandle FirstChildElement (const std::string &_value) const
 
TiXmlHandle Child (const std::string &_value, int index) const
 
TiXmlHandle ChildElement (const std::string &_value, int index) const
 
TiXmlNode * ToNode () const
 
TiXmlElement * ToElement () const
 
TiXmlText * ToText () const
 
TiXmlUnknown * ToUnknown () const
 
TiXmlNode * Node () const
 
TiXmlElement * Element () const
 
TiXmlText * Text () const
 
TiXmlUnknown * Unknown () const
 

Private Attributes

TiXmlNode * node
 

Detailed Description

TinyXML class. See http://www.grinninglizard.com/tinyxml.

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
}

See

See Also
http://www.grinninglizard.com/tinyxml

Definition at line 1815 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 1818 of file tinyxml.h.

References node.

Referenced by Child(), ChildElement(), FirstChild(), and FirstChildElement().

TiXmlHandle::TiXmlHandle ( const TiXmlHandle &  ref)
inline

Copy constructor.

Definition at line 1822 of file tinyxml.h.

References node.

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 1723 of file tinyxml_inl.h.

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

Referenced by Child().

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 1704 of file tinyxml_inl.h.

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

TiXmlHandle TiXmlHandle::Child ( const std::string &  _value,
int  index 
) const
inline

Definition at line 1866 of file tinyxml.h.

References Child().

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 1761 of file tinyxml_inl.h.

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

Referenced by ChildElement().

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 1742 of file tinyxml_inl.h.

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

TiXmlHandle TiXmlHandle::ChildElement ( const std::string &  _value,
int  index 
) const
inline

Definition at line 1869 of file tinyxml.h.

References ChildElement().

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

Definition at line 1904 of file tinyxml.h.

References ToElement().

TiXmlHandle TiXmlHandle::FirstChild ( ) const

Return a handle to the first child node.

Definition at line 1656 of file tinyxml_inl.h.

References TiXmlHandle().

Referenced by FirstChild().

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

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

Definition at line 1668 of file tinyxml_inl.h.

References TiXmlHandle().

TiXmlHandle TiXmlHandle::FirstChild ( const std::string &  _value) const
inline

Definition at line 1859 of file tinyxml.h.

References FirstChild().

TiXmlHandle TiXmlHandle::FirstChildElement ( ) const

Return a handle to the first child element.

Definition at line 1680 of file tinyxml_inl.h.

References TiXmlHandle().

Referenced by FirstChildElement().

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

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

Definition at line 1692 of file tinyxml_inl.h.

References TiXmlHandle().

TiXmlHandle TiXmlHandle::FirstChildElement ( const std::string &  _value) const
inline

Definition at line 1862 of file tinyxml.h.

References FirstChildElement().

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

Definition at line 1898 of file tinyxml.h.

References ToNode().

TiXmlHandle TiXmlHandle::operator= ( const TiXmlHandle &  ref)
inline

Definition at line 1825 of file tinyxml.h.

References node.

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

Definition at line 1910 of file tinyxml.h.

References ToText().

TiXmlElement* TiXmlHandle::ToElement ( ) const
inline

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

Definition at line 1881 of file tinyxml.h.

References node, and TiXmlNode::ToElement().

Referenced by Element().

TiXmlNode* TiXmlHandle::ToNode ( ) const
inline

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

Definition at line 1876 of file tinyxml.h.

References node.

Referenced by Node().

TiXmlText* TiXmlHandle::ToText ( ) const
inline

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

Definition at line 1886 of file tinyxml.h.

References node, and TiXmlNode::ToText().

Referenced by Text().

TiXmlUnknown* TiXmlHandle::ToUnknown ( ) const
inline

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

Definition at line 1891 of file tinyxml.h.

References node, and TiXmlNode::ToUnknown().

Referenced by Unknown().

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

Definition at line 1916 of file tinyxml.h.

References ToUnknown().

Member Data Documentation

TiXmlNode* TiXmlHandle::node
private

Definition at line 1921 of file tinyxml.h.

Referenced by operator=(), TiXmlHandle(), ToElement(), ToNode(), ToText(), and ToUnknown().

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