Provided by: libwebservice-validator-html-w3c-perl_0.28-2_all bug


       WebService::Validator::HTML::W3C - Access the W3Cs online HTML validator


           use WebService::Validator::HTML::W3C;

           my $v = WebService::Validator::HTML::W3C->new(
                       detailed    =>  1

           if ( $v->validate("") ) {
               if ( $v->is_valid ) {
                   printf ("%s is valid\n", $v->uri);
               } else {
                   printf ("%s is not valid\n", $v->uri);
                   foreach my $error ( @{$v->errors} ) {
                       printf("%s at line %d\n", $error->msg,
           } else {
               printf ("Failed to validate the website: %s\n", $v->validator_error);


       WebService::Validator::HTML::W3C provides access to the W3C's online Markup validator. As
       well as reporting on whether a page is valid it also provides access to a detailed list of
       the errors and where in the validated document they occur.


           my $v = WebService::Validator::HTML::W3C->new();

       Returns a new instance of the WebService::Validator::HTML::W3C object.

       There are various options that can be set when creating the Validator object like so:

           my $v = WebService::Validator::HTML::W3C->new( http_timeout => 20 );

           The URI of the validator to use.  By default this accesses the W3Cs validator at
  If you have a local installation of the validator (
           recommended if you wish to do a lot of testing ) or wish to use a validator at another
           location then you can use this option. Please note that you need to use the full path
           to the validator cgi.

       ua  The user agent to use. Should be an LWP::UserAgent object or something that provides
           the same interface. If this argument is provided, the "http_timeout" and "proxy"
           arguments are ignored.

           How long (in seconds) to wait for the HTTP connection to timeout when contacting the
           validator. By default this is 30 seconds.

           This fetches the XML response from the validator in order to provide information for
           the errors method. You should set this to true if you intend to use the errors method.

           An HTTP proxy to use when communicating with the validation service.

           Controls which output format is used. Can be either xml or soap12.

           The default is soap12 as the XML format is deprecated and is likely to be removed in
           the future.

           The default will always work so unless you're using a locally installed Validator you
           can safely ignore this.

           $v->validate( 'http:://' );

       Validate a URI. Returns 0 if the validation fails (e.g if the validator cannot be
       reached), otherwise 1.

           $v->validate_file( './file.html' );

       Validate a file by uploading it to the W3C Validator. NB This has only been tested on a
       Linux box so may not work on non unix machines.

           $v->validate_markup( $markup );

       Validate a scalar containing HTML.

   Alternate interface
       You can also pass a hash in to specify what you wish to validate. This is provided to
       ensure compatibility with the CSS validator module.

               $v->validate( uri => '' );
               $v->validate( string => $markup );
               $v->validate( file => './file.html' );


       Returns true (1) if the URI validated otherwise 0.


       Returns the URI of the last page on which validation succeeded.

           $num_errors = $v->num_errors();

       Returns the number of errors that the validator encountered.

       Synonym for num_errors. There to match CSS Validator interface.

           $num_errors = $v->warningcount();

       Returns the number of warnings that the validator encountered.

           $errors = $v->errors();

           foreach my $err ( @$errors ) {
               printf("line: %s, col: %s\n\terror: %s\n",
                       $err->line, $err->col, $err->msg);

       Returns an array ref of WebService::Validator::HTML::W3C::Error objects.  These have line,
       col and msg methods that return a line number, a column in that line and the error that
       occurred at that point.

       Note that you need XML::XPath for this to work and you must have initialised
       WebService::Validator::HTML::W3C with the detailed option. If you have not set the
       detailed option a warning will be issued, the detailed option will be set and a second
       request made to the validator in order to fetch the required information.

       If there was a problem processing the detailed information then this method will return 0.

           $warnings = $v->warnings();

       Works exactly the same as errors only returns an array ref of
       WebService::Validator::HTML::W3C::Warning objects. In all other respects it's the same.

           $error = $v->validator_error();

       Returns a string indicating why validation may not have occurred. This is not the reason
       that a webpage was invalid. It is the reason that no meaningful information about the
       attempted validation could be obtained. This is most likely to be an HTTP error

       Possible values are:

       You need to supply a URI to validate
           You didn't pass a URI to the validate method

       You need to supply a URI with a scheme
           The URI you passed to validate didn't have a scheme on the front. The W3C validator
           can't handle URIs like but instead needs URIs of the form

       Not a W3C Validator or Bad URI
           The URI did not return the headers that WebService::Validator::HTML::W3C relies on so
           it is likely that there is not a W3C Validator at that URI.  The other possibility is
           that it didn't like the URI you provided. Sadly the Validator doesn't give very useful
           feedback on this at the moment.

       Could not contact validator
           WebService::Validator::HTML::W3C could not establish a connection to the URI.

       Did not get a sensible result from the validator
           Should never happen and most likely indicates a problem somewhere but on the off
           chance that WebService::Validator::HTML::W3C is unable to make sense of the response
           from the validator you'll get this error.

       Result format does not appear to be SOAP|XML
           If you've asked for detailed results and the reponse from the validator isn't in the
           expected format then you'll get this error. Most likely to happen if you ask for SOAP
           output from a validator that doesn't support that format.

       You need to provide a uri, string or file to validate
           You've passed in a hash ( or in fact more than one argument ) to validate but the hash
           does not contain one of the three expected keys.

           $uri = $v->validator_uri();

       Returns or sets the URI of the validator to use. Please note that you need to use the full
       path to the validator cgi.

           $timeout = $v->http_timeout();

       Returns or sets the timeout for the HTTP request.


       Please note that there is also an official W3C module that is part of the
       W3C::LogValidator distribution. However that module is not very useful outside the
       constraints of that package. WebService::Validator::HTML::W3C is meant as a more general
       way to access the W3C Validator.

       HTML::Validator uses nsgmls to validate against the W3Cs DTDs. You have to fetch the
       relevant DTDs and so on.

       There is also the HTML::Parser based HTML::Lint which mostly checks for known tags rather
       than XML/HTML validity.

       WebService::Validator::CSS::W3C provides the same functionality as this module for the
       W3C's CSS validator.


       This module is not in any way associated with the W3C so please do not report any problems
       with this module to them. Also please remember that the online Validator is a shared
       resource so do not abuse it. This means sleeping between requests. If you want to do a lot
       of testing against it then please consider downloading and installing the Validator
       software which is available from the W3C. Debian testing users will also find that it is
       available via apt-get.


       While the interface to the Validator is fairly stable it may be updated. I will endeavour
       to track any changes with this module so please check on CPAN for new versions if you find
       things break. Also note that this module is only guaranteed to work with the currently
       stable version of the validator. It will most likely work with any Beta versions but don't
       rely on it.

       If in doubt please try and run the test suite before reporting bugs. Note that in order to
       run tests against the validator service you will need to have a connection to the internet
       and also set an environment variable called TEST_AUTHOR.

       That said I'm very happy to hear about bugs. All the more so if they come with patches ;).

       Please use <> for filing bug reports, and indeed feature requests. The
       code can also be found on github <


       To the various people on the code review ladder mailing list who provided useful

       Carl Vincent provided a patch to allow for proxy support.

       Chris Dolan provided a patch to allow for custom user agents.

       Matt Ryder provided a patch for support of the explanations in the SOAP output.


       author email or via <>.


       Struan Donald <>



       Copyright (C) 2003-2008 Struan Donald. All rights reserved.


       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.