C++ TiXmlNode::PreviousSibling方法代码示例

Xml::node_iterator& Xml::node_iterator::
operator--() {
    TiXmlNode* prev = node.updTiNode().PreviousSibling();
    while (prev && !nodeTypeIsAllowed(allowed, prev->Type()))
        prev = prev->PreviousSibling();
    node = Node(prev);
    return *this;
}

    // If the supplied Xml document has zero or more than one top-level element,
    // or has top-level text, we'll add <_Root> elements </_Root> to 
    // encapsulate all the top-level text and element nodes (this may also
    // surround top-level comments and unknowns if they occur between the text
    // and elements. A pointer to the root element (whether original or added) 
    // is returned.
    TiXmlElement* addRootElementIfNeeded() {
        // Find the first element or text node, and remember the node that
        // preceded it since that's where we may be inserting the new root
        // element.
        TiXmlNode* nodeBeforeFirst = 0;
        TiXmlNode* firstEltOrText = m_tixml.FirstChild();
        while (  firstEltOrText && 
               !(firstEltOrText->ToElement()||firstEltOrText->ToText()))
        {   nodeBeforeFirst = firstEltOrText;
            firstEltOrText = firstEltOrText->NextSibling(); }

        if (!firstEltOrText) {
            // No top level element or text node. We'll just append an empty
            // _Root element to the end of whatever's there.
            TiXmlElement* root = new TiXmlElement("_Root");
            m_tixml.LinkEndChild(root);
            return root;
        }

        // There is at least one element or text node at the top level; the 
        // first one is pointed to by firstEltOrText, and the node just before 
        // that (if any) is pointed to by nodeBeforeFirst. Now find the last 
        // top-level element or text node.
        TiXmlNode* lastEltOrText = m_tixml.LastChild();
        while (  lastEltOrText && 
               !(lastEltOrText->ToElement()||lastEltOrText->ToText()))
            lastEltOrText = lastEltOrText->PreviousSibling();

        assert(lastEltOrText); // should have at least re-found the first one!

        // If the extremely likely case that the first and last are the same 
        // node and that node is an element, then the document is already in the
        // right format and we don't have to do anything to it.
        if (firstEltOrText==lastEltOrText && firstEltOrText->ToElement())
            return firstEltOrText->ToElement();

        // Now we know there is top-level text or more than one top-level
        // element so we are going to have to surround everything between
        // first and last with a new root element.
        TiXmlElement* root = new TiXmlElement("_Root");

        TiXmlNode* nextToMove = firstEltOrText;
        while(true) {
            assert(nextToMove); // can't happen!
            TiXmlNode* moveMe = nextToMove;
            nextToMove = moveMe->NextSibling();
            root->LinkEndChild(m_tixml.DisconnectChild(moveMe));
            // Did we just move the last element or text node?
            if (moveMe == lastEltOrText) break;
        }

        // Now link the new root element right where we found the first
        // element or text node.
        if (nodeBeforeFirst) m_tixml.LinkAfterChild(nodeBeforeFirst, root);
        else                 m_tixml.LinkBeginChild(root);

        return root;
    }

Xml::node_iterator Xml::node_iterator::
operator--(int) {
    Node save(node);
    TiXmlNode* prev = node.updTiNode().PreviousSibling();
    while (prev && !nodeTypeIsAllowed(allowed, prev->Type()))
        prev = prev->PreviousSibling();
    node = Node(prev);
    return node_iterator(save);
}

//.........这里部分代码省略.........

		node = doc.RootElement();
		assert( node );
		XmlTest( "Root element exists.", true, ( node != 0 && node->ToElement() ) );
		XmlTest ( "Root element value is 'ToDo'.", "ToDo",  node->Value());

		node = node->FirstChild();
		XmlTest( "First child exists & is a comment.", true, ( node != 0 && node->ToComment() ) );
		node = node->NextSibling();
		XmlTest( "Sibling element exists & is an element.", true, ( node != 0 && node->ToElement() ) );
		XmlTest ( "Value is 'Item'.", "Item", node->Value() );

		node = node->FirstChild();
		XmlTest ( "First child exists.", true, ( node != 0 && node->ToText() ) );
		XmlTest ( "Value is 'Go to the'.", "Go to the", node->Value() );


		//////////////////////////////////////////////////////
		printf ("\n** Iterators. **\n");

		// Walk all the top level nodes of the document.
		count = 0;
		for( node = doc.FirstChild();
			 node;
			 node = node->NextSibling() )
		{
			count++;
		}
		XmlTest( "Top level nodes, using First / Next.", 3, count );

		count = 0;
		for( node = doc.LastChild();
			 node;
			 node = node->PreviousSibling() )
		{
			count++;
		}
		XmlTest( "Top level nodes, using Last / Previous.", 3, count );

		// Walk all the top level nodes of the document,
		// using a different syntax.
		count = 0;
		for( node = doc.IterateChildren( 0 );
			 node;
			 node = doc.IterateChildren( node ) )
		{
			count++;
		}
		XmlTest( "Top level nodes, using IterateChildren.", 3, count );

		// Walk all the elements in a node.
		count = 0;
		for( element = todoElement->FirstChildElement();
			 element;
			 element = element->NextSiblingElement() )
		{
			count++;
		}
		XmlTest( "Children of the 'ToDo' element, using First / Next.",
			3, count );

		// Walk all the elements in a node by value.
		count = 0;
		for( node = todoElement->FirstChild( "Item" );
			 node;
			 node = node->NextSibling( "Item" ) )

//.........这里部分代码省略.........
#endif

	node = doc.RootElement();
	XmlTest( "Root element exists.", true, ( node != 0 && node->ToElement() ) );
	XmlTest ( "Root element value is 'ToDo'.", "ToDo",  node->Value());

	node = node->FirstChild();
	XmlTest( "First child exists & is a comment.", true, ( node != 0 && node->ToComment() ) );
	node = node->NextSibling();
	XmlTest( "Sibling element exists & is an element.", true, ( node != 0 && node->ToElement() ) );
	XmlTest ( "Value is 'Item'.", "Item", node->Value() );

	node = node->FirstChild();
	XmlTest ( "First child exists.", true, ( node != 0 && node->ToText() ) );
	XmlTest ( "Value is 'Go to the'.", "Go to the", node->Value() );


	//////////////////////////////////////////////////////
	printf ("\n** Iterators. **\n");

	// Walk all the top level nodes of the document.
	count = 0;
	for( node = doc.FirstChild();
		 node;
		 node = node->NextSibling() )
	{
		count++;
	}
	XmlTest( "Top level nodes, using First / Next.", 3, count );

	count = 0;
	for( node = doc.LastChild();
		 node;
		 node = node->PreviousSibling() )
	{
		count++;
	}
	XmlTest( "Top level nodes, using Last / Previous.", 3, count );

	// Walk all the top level nodes of the document,
	// using a different sytax.
	count = 0;
	for( node = doc.IterateChildren( 0 );
		 node;
		 node = doc.IterateChildren( node ) )
	{
		count++;
	}
	XmlTest( "Top level nodes, using IterateChildren.", 3, count );

	// Walk all the elements in a node.
	count = 0;
	for( element = todoElement->FirstChildElement();
		 element;
		 element = element->NextSiblingElement() )
	{
		count++;
	}
	XmlTest( "Children of the 'ToDo' element, using First / Next.",
		3, count );

	// Walk all the elements in a node by value.
	count = 0;
	for( node = todoElement->FirstChild( "Item" );
		 node;
		 node = node->NextSibling( "Item" ) )

//.........这里部分代码省略.........
#endif
        
	node = doc.RootElement();
	XmlTest( "Root element exists.", true, ( node != 0 && node->ToElement() ) );
	XmlTest ( "Root element value is 'ToDo'.", "ToDo",  node->Value());

	node = node->FirstChild();
	XmlTest( "First child exists & is a comment.", true, ( node != 0 && node->ToComment() ) );
	node = node->NextSibling();
	XmlTest( "Sibling element exists & is an element.", true, ( node != 0 && node->ToElement() ) );
	XmlTest ( "Value is 'Item'.", "Item", node->Value() );

	node = node->FirstChild();
	XmlTest ( "First child exists.", true, ( node != 0 && node->ToText() ) );
	XmlTest ( "Value is 'Go to the'.", "Go to the", node->Value() );


	//////////////////////////////////////////////////////
	printf ("\n** Iterators. **\n");

	// Walk all the top level nodes of the document.
	count = 0;
	for( node = doc.FirstChild();
		 node;
		 node = node->NextSibling() )
	{
		count++;
	}
	XmlTest( "Top level nodes, using First / Next.", 3, count );

	count = 0;
	for( node = doc.LastChild();
		 node;
		 node = node->PreviousSibling() )
	{
		count++;
	}
	XmlTest( "Top level nodes, using Last / Previous.", 3, count );

	// Walk all the top level nodes of the document,
	// using a different sytax.
	count = 0;
	for( node = doc.IterateChildren( 0 );
		 node;
		 node = doc.IterateChildren( node ) )
	{
		count++;
	}
	XmlTest( "Top level nodes, using IterateChildren.", 3, count );

	// Walk all the elements in a node.
	count = 0;
	for( element = todoElement->FirstChildElement();
		 element;
		 element = element->NextSiblingElement() )
	{
		count++;
	}
	XmlTest( "Children of the 'ToDo' element, using First / Next.",
		3, count );

	// Walk all the elements in a node by value.
	count = 0;
	for( node = todoElement->FirstChild( "Item" );
		 node;
		 node = node->NextSibling( "Item" ) )