DOMDocument::validate

    (PHP 5, PHP 7, PHP 8)

    DOMDocument::validate — Validates the document based on its DTD

    Description

    public DOMDocument::validate(): bool

    Validates the document based on its DTD.

    You can also use the validateOnParse property of DOMDocument to make a DTD validation.

    Parameters

    This function has no parameters.

    Return Values

    Returns true on success or false on failure. If the document has no DTD attached, this method will return false.

    Examples

    Example #1 Example of DTD validation

    <?php
    $dom     = new DOMDocument;
    $dom->load('book.xml');
    if (    $dom->validate()) {
    echo     "This document is valid!\n";
    }
    ?>

    You can also validate your XML file while loading it:

    <?php
    $dom     = new DOMDocument;
    $dom->validateOnParse = true;
    $dom->load('book.xml');
    ?>

    See Also

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    User Contributed Notes 3 notes

    up
    11
    a dot schaffhirt at sedna-soft dot de
    16 years ago
    When validating documents with this method there are two issues I don't like about it. First, it creates a bunch of warnings, which one would not expect, as the plot of calling this method is preventing any warnings that could occur when erroneously relying on the document's validity. Second, it only returns a boolean with no chance of getting additional details about the reasons for rendering invalid.

    That's the reason for me to use a little wrapper, which I post here in case anyone finds it useful.

    Please note that it only works with PHP5 or later.

    <?php
    class MyDOMDocument {
    private     $_delegate;
    private     $_validationErrors;

    public function     __construct (DOMDocument $pDocument) {
    $this->_delegate = $pDocument;
    $this->_validationErrors = array();
    }

    public function     __call ($pMethodName, $pArgs) {
    if (    $pMethodName == "validate") {
    $eh = set_error_handler(array($this, "onValidateError"));
    $rv = $this->_delegate->validate();
    if (    $eh) {
    set_error_handler($eh);
    }
    return     $rv;
    }
    else {
    return     call_user_func_array(array($this->_delegate, $pMethodName), $pArgs);
    }
    }
    public function     __get ($pMemberName) {
    if (    $pMemberName == "errors") {
    return     $this->_validationErrors;
    }
    else {
    return     $this->_delegate->$pMemberName;
    }
    }
    public function     __set ($pMemberName, $pValue) {
    $this->_delegate->$pMemberName = $pValue;
    }
    public function     onValidateError ($pNo, $pString, $pFile = null, $pLine = null, $pContext = null) {
    $this->_validationErrors[] = preg_replace("/^.+: */", "", $pString);
    }
    }
    ?>

    <?php
    // $doc is a DOMDocument object
    $myDoc = new MyDOMDocument($doc); // copy constructor

    // do anything with $myDoc that you would with $doc

    $isValid = $myDoc->validate(); // won't create warnings
    if (!$isValid) {
    print_r($myDoc->errors); // the array all warnings are collected in
    }
    ?>

    Maybe you need to change the the part
    preg_replace("/^.+: */", "", $pString)
    to something different depending on your system's error reporting settings (HTML or plain text), whatsoever

    Best Regards,

    Anja
    up
    2
    cabral dot brc at gmail dot com
    14 years ago
    I was trying to validate my SVG file just to get the IDs with getElementById(),

    <?xml version="1.0"?>
    <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
    <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <text id="text_titulo" x="150" y="20" font-family="Arial" font-size="15px" style="font-weight:bold;">Title</text>
    <text id="text_subtitulo" x="200" y="35" font-family="Arial" font-size="10px">Sub Title</text>
    <g transform="translate(0,50) scale(0.1)">
    <a id="a_AC" ...... >
    <polygon id="polygon_AC" ....... />
    </a>
    </g>
    </svg>

    but when calling $dom->load(), it was getting the errors "failed to open stream" and "Validation failed: no DTD found !I/O warning : failed to load external entity"
    so I created my own validation wrapper (I just want to find the IDs with getElementById() )

    <?php
    $docSVG     = new DOMDocument();
    $docSVG->load(realpath($filepath));
    setAllId($docSVG);


    function     setAllId($DOMNode){
    if(    $DOMNode->hasChildNodes()){
    foreach (    $DOMNode->childNodes as $DOMElement) {
    if(    $DOMElement->hasAttributes()){
    $id=$DOMElement->getAttribute("id");
    if(    $id){
    $DOMElement->setIdAttribute("id",$id);
    }
    }
    setAllId($DOMElement);
    }
    }
    }
    ?>
    up
    -6
    darren at viamedia dot co dot za
    16 years ago
    If you are loading xml with the intention of validating it against an internal dtd and you have experienced issues with the validation it could be related to missing LIBXML constants.

    I found this post by "aidan at php dot net" in root level dom docs and thought it might be more useful here:
    As of PHP 5.1, libxml options may be set using constants rather than the use of proprietary DomDocument properties.

    DomDocument->resolveExternals is equivilant to setting
    LIBXML_DTDLOAD
    LIBXML_DTDATTR

    DomDocument->validateOnParse is equivilant to setting
    LIBXML_DTDLOAD
    LIBXML_DTDVALID

    PHP 5.1 users are encouraged to use the new constants.

    Example:
    <?php
    $dom     = new DOMDocument;
    // Resolve externals
    $dom->load($file, LIBXML_DTDLOAD|LIBXML_DTDATTR);
    // OR
    // Validate against DTD
    $dom->load($file, LIBXML_DTDLOAD|LIBXML_DTDVALID);
    $dom->validate();
    ?>
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