The issues around mixed content took me some experimentation to remember, so I thought I'd add this note to save others time.
When your markup is something like: <div><p>First text.</p><ul><li><p>First bullet</p></li></ul></div>, you'll get XML_ELEMENT_NODEs that are quite regular. The <div> has children <p> and <ul> and the nodeValue for both <p>s yields the text you expect.
But when your markup is more like <p>This is <b>bold</b> and this is <i>italic</i>.</p>, you realize that the nodeValue for XML_ELEMENT_NODEs is not reliable. In this case, you need to look at the <p>'s child nodes. For this example, the <p> has children: #text, <b>, #text, <i>, #text.
In this example, the nodeValue of <b> and <i> is the same as their #text children. But you could have markup like: <p>This <b>is bold and <i>bold italic</i></b>, you see?</p>. In this case, you need to look at the children of <b>, which will be #text, <i>, because the nodeValue of <b> will not be sufficient.
XML_TEXT_NODEs have no children and are always named '#text'. Depending on how whitespace is handled, your tree may have "empty" #text nodes as children of <body> and elsewhere.
Attributes are nodes, but I had forgotten that they are not in the tree expressed by childNodes. Walking the full tree using childNodes will not visit any attribute nodes.
The DOMNode class
(PHP 5)
Krótki opis klasy
Właściwości
- nodeName
-
Returns the most accurate name for the current node type
- nodeValue
-
The value of this node, depending on its type
- nodeType
-
Gets the type of the node. One of the predefined XML_xxx_NODE constants
- parentNode
-
The parent of this node
- childNodes
-
A DOMNodeList that contains all children of this node. If there are no children, this is an empty DOMNodeList.
- firstChild
-
The first child of this node. If there is no such node, this returns
NULL. - lastChild
-
The last child of this node. If there is no such node, this returns
NULL. - previousSibling
-
The node immediately preceding this node. If there is no such node, this returns
NULL. - nextSibling
-
The node immediately following this node. If there is no such node, this returns
NULL. - attributes
-
A DOMNamedNodeMap containing the attributes of this node (if it is a DOMElement) or
NULLotherwise. - ownerDocument
-
The DOMDocument object associated with this node.
- namespaceURI
-
The namespace URI of this node, or
NULLif it is unspecified. - prefix
-
The namespace prefix of this node, or
NULLif it is unspecified. - localName
-
Returns the local part of the qualified name of this node.
- baseURI
-
The absolute base URI of this node or
NULLif the implementation wasn't able to obtain an absolute URI. - textContent
-
This attribute returns the text content of this node and its descendants.
Notatki
Informacja:
The DOM extension uses UTF-8 encoding. Use utf8_encode() and utf8_decode() to work with texts in ISO-8859-1 encoding or Iconv for other encodings.
Spis treści
- DOMNode::appendChild — Adds new child at the end of the children
- DOMNode::C14N — Canonicalize nodes to a string
- DOMNode::C14NFile — Canonicalize nodes to a file
- DOMNode::cloneNode — Clones a node
- DOMNode::getLineNo — Get line number for a node
- DOMNode::getNodePath — Get an XPath for a node
- DOMNode::hasAttributes — Checks if node has attributes
- DOMNode::hasChildNodes — Checks if node has children
- DOMNode::insertBefore — Adds a new child before a reference node
- DOMNode::isDefaultNamespace — Checks if the specified namespaceURI is the default namespace or not
- DOMNode::isSameNode — Indicates if two nodes are the same node
- DOMNode::isSupported — Checks if feature is supported for specified version
- DOMNode::lookupNamespaceURI — Gets the namespace URI of the node based on the prefix
- DOMNode::lookupPrefix — Gets the namespace prefix of the node based on the namespace URI
- DOMNode::normalize — Normalizes the node
- DOMNode::removeChild — Removes child from list of children
- DOMNode::replaceChild — Replaces a child
getAttribute() returns an empty string if the requested attribute doesn't exist in the node.
If you have empty $node->textContent and $node->textValue, check if document that is loaded have UTF-8 encoding.
Just discovered that node->nodeValue strips out all the tags
For a reference with more information about the XML DOM node types, see http://www.w3schools.com/dom/dom_nodetype.asp
(When using PHP DOMNode, these constants need to be prefaced with "XML_")
For clarification:
The assumingly 'discoverd' by previous posters and seemingly undocumented methods (.getElementsByTagName and .getAttribute) on this class (DOMNode) are in fact methods of the class DOMElement, which inherits from DOMNode.
See: http://www.php.net/manual/en/class.domelement.php
You cannot simply overwrite $textContent, to replace the text content of a DOMNode, as the missing readonly flag suggests. Instead you have to do something like this:
<?php
$node->removeChild($node->firstChild);
$node->appendChild(new DOMText('new text content'));
?>
This example shows what happens:
<?php
$doc = DOMDocument::loadXML('<node>old content</node>');
$node = $doc->getElementsByTagName('node')->item(0);
echo "Content 1: ".$node->textContent."\n";
$node->textContent = 'new content';
echo "Content 2: ".$node->textContent."\n";
$newText = new DOMText('new content');
$node->appendChild($newText);
echo "Content 3: ".$node->textContent."\n";
$node->removeChild($node->firstChild);
$node->appendChild($newText);
echo "Content 4: ".$node->textContent."\n";
?>
The output is:
Content 1: old content // starting content
Content 2: old content // trying to replace overwriting $node->textContent
Content 3: old contentnew content // simply appending the new text node
Content 4: new content // removing firstchild before appending the new text node
If you want to have a CDATA section, use this:
<?php
$doc = DOMDocument::loadXML('<node>old content</node>');
$node = $doc->getElementsByTagName('node')->item(0);
$node->removeChild($node->firstChild);
$newText = $doc->createCDATASection('new cdata content');
$node->appendChild($newText);
echo "Content withCDATA: ".$doc->saveXML($node)."\n";
?>
This class apparently also has a getElementsByTagName method.
I was able to confirm this by evaluating the output from DOMNodeList->item() against various tests with the is_a() function.
It took me forever to find a mapping for the XML_*_NODE constants. So I thought, it'd be handy to paste it here:
1 XML_ELEMENT_NODE
2 XML_ATTRIBUTE_NODE
3 XML_TEXT_NODE
4 XML_CDATA_SECTION_NODE
5 XML_ENTITY_REFERENCE_NODE
6 XML_ENTITY_NODE
7 XML_PROCESSING_INSTRUCTION_NODE
8 XML_COMMENT_NODE
9 XML_DOCUMENT_NODE
10 XML_DOCUMENT_TYPE_NODE
11 XML_DOCUMENT_FRAGMENT_NODE
12 XML_NOTATION_NODE
And apparently also a setAttribute method too:
$node->setAttribute( 'attrName' , 'value' );
Try canonicalization:
<?php
$dom = new DOMDocument;
$dom->loadHTMLFile('http://www.example.com/');
echo $dom->documentElement->C14N();
?>
Or output it to a file, using C14NFile()
Undocumented stuff ;)
This class has a getAttribute method.
Assume that a DOMNode object $ref contained an anchor taken out of a DOMNode List. Then
$url = $ref->getAttribute('href');
would isolate the url associated with the href part of the anchor.
