A TiXmlHandle is a class that wraps a node pointer with null checks; this is an incredibly useful thing. 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. | |
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. More... | |
TiXmlHandle | Child (int index) const |
Return a handle to the "index" child. More... | |
TiXmlHandle | ChildElement (const char *value, int index) const |
Return a handle to the "index" child element with the given name. More... | |
TiXmlHandle | ChildElement (int index) const |
Return a handle to the "index" child element. More... | |
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 |
Return the handle as a TiXmlNode. More... | |
TiXmlElement * | ToElement () const |
Return the handle as a TiXmlElement. More... | |
TiXmlText * | ToText () const |
Return the handle as a TiXmlText. More... | |
TiXmlUnknown * | ToUnknown () const |
Return the handle as a TiXmlUnknown. More... | |
TiXmlNode * | Node () const |
TiXmlElement * | Element () const |
TiXmlText * | Text () const |
TiXmlUnknown * | Unknown () const |
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 }
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.
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.
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.
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.
References TiXmlNode::NextSiblingElement(), and TiXmlHandle().
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inline |
References ToElement().
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inline |
References ToNode().
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inline |
References ToText().
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inline |
Return the handle as a TiXmlElement.
This may return null.
References TiXmlNode::ToElement().
Referenced by Element().
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inline |
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inline |
Return the handle as a TiXmlText.
This may return null.
References TiXmlNode::ToText().
Referenced by Text().
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inline |
Return the handle as a TiXmlUnknown.
This may return null.
References TiXmlNode::ToUnknown().
Referenced by Unknown().
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inline |
References ToUnknown().