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<div class="doc">
<h2>Markup Validator Web Service API<br />
SOAP 1.2 validation interface documentation</h2>

<p>Interface applications with the Markup Validator through its <strong>experimental</strong> API. </p>
<p><strong>Note</strong>: Please be considerate in using this shared, free resource. 
	Consider <a href="install.html">Installing your own instance of the validator</a>
	for smooth and fast operation. Excessive use of the W3C Validation Service
	will be blocked.</p>


<h3 id="TableOfContents">Table of Contents</h3>

    <div id="toc">
      <ul>
        <li><a href="#requestformat">Validation Request Format</a></li>
        <li><a href="#soap12format">SOAP format description</a>
         <ul>
          <li><a href="#soap12_sample">sample SOAP 1.2 validation response</a></li>
          <li><a href="#soap12response">SOAP1.2 response format reference</a></li>
          <li><a href="#soap12message">SOAP1.2 atomic message (error or warning) format reference</a></li>
         </ul>
        </li>
        <li><a href="#libs">Libraries</a></li>
        <li><a href="#http_headers">Using HTTP headers to know validation results</a></li>
      </ul>
    </div>
    
    <p id="skip"></p>

<h3 id="requestformat">Validation Request Format</h3>

<p>Below is a table of the parameter you can use to send a query to the W3C Markup Validator.</p>
<p>If you want to use W3c's public validation server, use the parameters below
 in conjunction with the following base URI:<br />
<kbd>http://validator.w3.org/check</kbd> <br />
(replace with the address of your own server if you want to call a private instance of the validator)</p>

<p><strong>Note</strong>: If you wish to call the validator programmatically for a batch of documents,
please make sure that your script will <code>sleep</code> for <strong>at least 1 second</strong> 
between requests. The Markup Validation service is a free, public service for all, your respect
is appreciated. thanks.</p>

<table class="refdoc">
<tr>
<th>Parameter</th><th>Description</th><th>Default value</th>
</tr>
<tr>
  <th>uri</th>
  <td>The <acronym title="Universal Resource Locator">URL</acronym> of the document to validate</td>
  <td>None, but either this parameter, or <code>uploaded_file</code>, 
  or <code>fragment</code> must be given.</td>
</tr>
<tr>
  <th>uploaded_file</th>
  <td>The document to validate, POSTed as multipart/form-data</td>
  <td>None, but either this parameter, or <code>uri</code>,   
  or <code>fragment</code> must be given.</td>
</tr>
<tr>
  <th>fragment</th>
  <td>The source of the document to validate. Full documents only. 
  At the moment, will only work if data is sent with the UTF-8 encoding.</td>
  <td>None, but either this parameter, or <code>uri</code>,
  or <code>uploaded_file</code> must be given.</td>
</tr>
<tr>
  <th>output</th>
  <td>triggers the various outputs formats of the validator. If unset, the usual
  Web format will be sent. If set to <code>soap12</code>, the SOAP1.2 interface will 
  be triggered. See <a href="#soap12format">below for the SOAP 1.2 response format description</a>.</td>
  <td>unset</td>
</tr>
<tr>
  <th>charset</th>
  <td>Character encoding override: 
  Specify the character encoding to use when parsing the document. When used with
  the auxiliary parameter <code>fbc</code> set to 1, the given encoding will only be used as 
  a fallback value, in case the charset is absent or unrecognized. Note that this parameter
  is ignored if validating a <code>fragment</code> with the direct input interface.</td>
  <td>None, by default the validator detects the charset of the document automatically.</td>
</tr>
<tr>
  <th>doctype</th>
  <td>Document Type override:
  Specify the Document Type (DOCTYPE) to use when parsing the document. When used 
  with  the auxiliary parameter <code>fbd</code> set to 1, the given document type will only be used
  as a fallback value, in case the document's DOCTYPE declaration is missing or unrecognized.</td>
  <td>None, by default the validator detects the document type of the document automatically.</td>
</tr>
<tr>
  <th>verbose</th>
  <td>In the web interface, when set to 1, will make error messages, explanations 
  and other diagnostics more verbose. In SOAP output, does not have any impact.</td>
  <td>0 (unset)</td>
</tr>
<tr>
  <th>ss</th>
  <td> as <em>show source</em>. In the web interface, triggers the display of the source
  after the validation results. In SOAP output, does not have any impact.</td>
  <td>0 (unset)</td>
</tr>
<tr>
  <th>outline</th>
  <td>In the web interface, when set to 1, triggers the display of the document outline 
  after the validation results. In SOAP output, does not have any impact.</td>  
  <td>0 (unset)</td>
</tr>
</table>
<h3 id="soap12format">SOAP format description</h3>

<p>When called with parameter <code>output=soap12</code>, the validator will switch
to its SOAP 1.2 interface (experimental for now). Below is a sample response, as well as
a description of the most important elements of the response.</p>

<h4 id="soap12_sample">sample SOAP 1.2 validation response</h4>
<p>A SOAP response for the validation of a document (invalid) will look like this:</p>
<pre style="font-size: smaller"> 
&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
&lt;env:Envelope xmlns:env=&quot;http://www.w3.org/2003/05/soap-envelope&quot;&gt;
&lt;env:Body&gt;
&lt;<a href="#soap12_markupvalidationresponse">m:markupvalidationresponse</a>
env:encodingStyle=&quot;http://www.w3.org/2003/05/soap-encoding&quot; 
xmlns:m=&quot;http://www.w3.org/2005/10/markup-validator&quot;&gt;
    &lt;<a href="#soap12_uri">m:uri</a>&gt;http://qa-dev.w3.org/wmvs/HEAD/dev/tests/xhtml1-bogus-element.html&lt;/m:uri&gt;
    &lt;<a href="#soap12_checkedby">m:checkedby</a>&gt;http://validator.w3.org/&lt;/m:checkedby&gt;
    &lt;<a href="#soap12_doctype">m:doctype</a>&gt;-//W3C//DTD XHTML 1.0 Transitional//EN&lt;/m:doctype&gt;
    &lt;<a href="#soap12_charset">m:charset</a>&gt;utf-8&lt;/m:charset&gt;
    &lt;<a href="#soap12_validity">m:validity</a>&gt;false&lt;/m:validity&gt;
    &lt;<a href="#soap12_errors">m:errors</a>&gt;
        &lt;<a href="#soap12_errorcount">m:errorcount</a>&gt;1&lt;/m:errorcount&gt;
        &lt;<a href="#soap12_errorlist">m:errorlist</a>&gt;
          
            &lt;<a href="#soap12_error">m:error</a>&gt;
                &lt;<a href="#soap12_line">m:line</a>&gt;13&lt;/m:line&gt;
                &lt;<a href="#soap12_col">m:col</a>&gt;6&lt;/m:col&gt;                                           
                &lt;<a href="#soap12_message">m:message</a>&gt;element &quot;foo&quot; undefined&lt;/m:message&gt;
            &lt;/m:error&gt;
           
        &lt;/m:errorlist&gt;
    &lt;/m:errors&gt;
    &lt;m:warnings&gt;
        &lt;m:warningcount&gt;0&lt;/m:warningcount&gt;
        &lt;m:warninglist&gt;
        
        
        &lt;/m:warninglist&gt;
    &lt;/m:warnings&gt;
&lt;/m:markupvalidationresponse&gt;
&lt;/env:Body&gt;
&lt;/env:Envelope&gt;
</pre>
<h4 id="soap12response">SOAP1.2 response format reference</h4>

<table class="refdoc">
<tr><th>element</th><th>description</th></tr>
<tr>
  <th id="soap12_markupvalidationresponse">markupvalidationresponse</th>
  <td>The main element of the validation response. Encloses all other information about the validation results.</td>
</tr>
<tr>
  <th id="soap12_uri">uri</th>
  <td>the address of the document validated. Will (likely?) be <kbd>upload://Form Submission</kbd>
  if an uploaded document or fragment was validated.
  In <a href="http://www.w3.org/WAI/ER/">EARL</a> terms, this is the <kbd>TestSubject</kbd>.
  </td>
</tr>
<tr>
  <th id="soap12_checkedby">checkedby</th>
  <td>Location of the service which provided the validation result. 
  In <a href="http://www.w3.org/WAI/ER/">EARL</a> terms, this is the <kbd>Assertor</kbd>.
  </td>
</tr>
<tr>
  <th id="soap12_doctype">doctype</th>
  <td>Detected (or forced) Document Type for the validated document</td>
</tr>
<tr>
  <th id="soap12_charset">charset</th>
  <td>Detected (or forced) Character Encoding for the validated document</td>
</tr>
<tr>
  <th id="soap12_validity">validity</th>
  <td>Whether or not the document validated passed or not formal validation (true|false boolean)</td>
</tr>
<tr>
  <th id="soap12_errors">errors</th>
  <td>Encapsulates all data about errors encountered through the validation process</td>
</tr>
<tr>
  <th id="soap12_errorcount">errorcount</th>
  <td>a child of <a href="#soap12_errors">errors</a>, counts the number of errors listed</td>
</tr>
<tr>
  <th id="soap12_errorlist">errorlist</th>
  <td>a child of <a href="#soap12_errors">errors</a>, contains the list of errors (surprise!)</td>
</tr>
<tr>
  <th id="soap12_error">error</th>
  <td>a child of <a href="#soap12_errorlist">errorlist</a>, contains the information on a single 
  validation error. </td>
</tr>
</table>
<p><strong>Note</strong>: <code>warnings</code>, <code>warningcount</code>, 
<code>warninglist</code> and <code>warning</code> are similar to, respectively,
<code><a href="#soap12_errors">errors</a></code>, 
<code><a href="#soap12_errorcount">errorcount</a></code>, 
<code><a href="#soap12_errorlist">errorlist</a></code> and 
<code><a href="#soap12_error">error</a></code>.
</p>
<h4 id="soap12message">SOAP1.2 atomic message (error or warning) format reference</h4>
<p>As seen as the example above, the children of the <code><a href="#soap12_error">error</a></code>
element, but also the <code>warning</code> element are <code>line</code>, <code>col</code> and
<code>message</code>, defined below:</p>
<table class="refdoc">
<tr><th>element</th><th>description</th></tr>
<tr>
  <th id="soap12_line">line</th>
  <td>Within the source code of the validated document, refers to the line where the error was detected.</td>
</tr>
<tr>
  <th id="soap12_col">col</th>
  <td>Within the source code of the validated document, refers to the line where the column was detected.</td>
</tr>
<tr>
  <th id="soap12_message">message</th>
  <td>The actual error message</td>
</tr>
<tr>
  <th id="soap12_messageid">messageid</th>
  <td>@@ not implemented yet@@ - should be the number of the error, as addressed internally by the validator</td>
</tr>
</table>

<h3 id="libs">Libraries</h3>
<p>Building of libraries used to interact with the validator's API is <a href="http://www.w3.org/QA/2006/10/validator_api.html">encouraged</a>. If you are the 
    maintainer of such a library, <a href="../feedback.html">contact us</a> and we will list it here.</p>
<h4>Known libraries for the W3C Markup Validator API</h4>

<ul>
   <li><a href="http://search.cpan.org/dist/WebService-Validator-HTML-W3C/">WebService::Validator::HTML::W3C</a> in perl, 
       by Struan Donald.</li>
</ul>

<h3 id="http_headers">Using HTTP headers to know validation results</h3>

<p>Every validation result is served via the HTTP protocol, with custom headers giving a simple, quick way
    to get validation results without having to parse the results body. This is a simple (but poorer) alternative to using 
    the full API described above.</p>
    
<p>The HTTP headers for a validation results page will generally look like:</p>
<pre>
    HEAD 'http://validator.localhost/check?uri=http%3A%2F%2Fwww.w3.org'
    
    200 OK
    [...]
    Content-Language: en
    Content-Type: text/html; charset=utf-8
    X-W3C-Validator-Errors: 0
    X-W3C-Validator-Recursion: 1
    X-W3C-Validator-Status: Valid
</pre>

<p>The headers and their values are as follows:</p>
<table>
    <tr><th>Header</th><th>Value</th><th>Notes</th></tr>
    <tr>
        <td>X-W3C-Validator-Status</td>
        <td><code>Valid</code> or <code>Invalid</code></td>
        <td>May not be present if validation could not be performed (404 Not found, etc)</td>
    </tr>
    <tr>
        <td>X-W3C-Validator-Errors</td>
        <td>Number of Errors found during validation. <code>0</code> if no errors found.</td>
        <td>0 does not necessarily mean "valid" (it may mean that validation could not be performed)</td>
    </tr>
    <tr>
        <td>X-W3C-Validator-Recursion</td>
        <td>Integer. Generally, <code>1</code>. More if recursively validating validation results. 
           </td>
        <td>    The validator will use this in conjunction with its <code>Max Recursion</code> setup to avoid
               abusive recursion (Denial of Service attack).</td>
    </tr>
</table>
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