Provided by: libwiki-toolkit-plugin-diff-perl_0.12-3_all bug

NAME

       Wiki::Toolkit::Plugin::Diff - format differences between two Wiki::Toolkit pages

SYNOPSIS

         use Wiki::Toolkit::Plugin::Diff;
         my $plugin = Wiki::Toolkit::Plugin::Diff->new;
         $wiki->register_plugin( plugin => $plugin );   # called before any node reads
         my %diff = $plugin->differences( node => 'Imperial College',
                                       left_version => 3,
                                       right_version => 5);

DESCRIPTION

       A plug-in for Wiki::Toolkit sites, which provides a nice extract of differences between
       two versions of a node.

BASIC USAGE

       differences

         my %diff_vars = $plugin->differences(
             node          => "Home Page",
             left_version  => 3,
             right_version => 5
         );

       Takes a series of key/value pairs:

       ·   left_version

           The node version whose content we're considering canonical.

       ·   right_version

           The node version that we're showing the differences from.

       ·   meta_include

           Filter the list of metadata fields to only include a certain list in the diff output.
           The default is to include all metadata fields.

       ·   meta_exclude

           Filter the list of metadata fields to exclude certain fields from the diff output. The
           default is the following list, to match previous version (OpenGuides) behaviour:
              "qw(
              username
              comment
              __categories__checksum
              __locales__checksum )"

           Agreed this list is hopelessly inadequate, especially for OpenGuides.  Hopefully,
           future wiki designers will use the meta_include parameter to specify exactly what
           metadata they want to appear on the diff.

       The differences method returns a list of key/value pairs, which can be assigned to a hash:

       left_version
           The node version whose content we're considering canonical.

       right_version
           The node version that we're showing the differences from.

       content
           The (formatted) contents of the Left version of the node.

       diff
           An array of hashrefs of "hunks" of differences between the versions. It is assumed
           that the display will be rendered in HTML, and SPAN tags are inserted with a class of
           diff1 or diff2, to highlight which individual words have actually changed. Display the
           contents of diff using a <table>, with each member of the array corresponding to a row
           <TR>, and keys {left} and {right} being two columns <TD>.

           Usually you will want to feed this through a templating system, such as Template
           Toolkit, which makes iterating the AoH very easy.

ADVANCED

       Wiki::Toolkit::Plugin::Diff allows for a more flexible approach than HTML only rendering
       of pages. In particular, there are optional parameters to the constructor which control
       fine detail of the resultant output.

       If this is not sufficient, the module is also subclassable, and the programmer can supply
       alternative methods.

       METHODS

       Most of these are called internally by the plugin, but provide hooks for alternative code
       if the module is subclassed.

       new
             my $plugin = Wiki::Toolkit::Plugin::Diff->new( option => value, option => value...);

           Here, option can be one of the following:

           metadata_separator
               A string which is inserted between each metadata field, and also between the
               contents and the metadata. This defaults to "<br />\n" so as to render each
               metadata field on a new line.

           line_number_format
               Used to lay out the head line number for a difference hunk. The string is eval'ed
               with $_ containing the line number.  Default is "== Line \$_ ==" .

           word_matcher
               is a regular expression, used to tokenize the input string. This is the way of
               grouping together atomic sequences, so as to give a readable result. The default
               is the following:

                           &.+?;                   #HTML special characters e.g. &lt;
                           |<br\s*/>               #Line breaks
                           |\w+\s*                 #Word with trailing spaces
                           |.                      #Any other single character

       differences
           see above.

       line_number
           This method is called to format a line number into a suitable string.  The supplied
           routine performs the necessary substitution of $self->{line_number_format} using eval.

       serialise_metadata
           The purpose of this method is to turn a metadata hash into a string suitable for
           diffing.

       content_escape
           This method is used to apply the necessary quoting or escaping of characters that
           could appear in the content body, that could interfere with the rendering of the diff
           text.

       intradiff
           This method turns an array of hunks as returned by VCS::Lite::Delta->hunks into a side
           by side diff listing, with highlights indicating different words and punctuation.

           Currently, this is hardcoded to present the differences with HTML tags.

           This module is a prime candidate for migration into VCS::Lite, where this
           functionality really belongs.

       get_token
           This allows the "false positive" bug discovered by Earle Martin to be solved
           (rt.cpan.org #6284).  Effectively, the input strings (diff1 and diff2) are tokenised
           using the word_matcher regexp (see above), and turned into arrays of tokens.

           The default regexp absorbs trailing whitespace, to give a more readable result.
           However, if a word is followed by differing whitespace or no whitespace at all, this
           was throwing up a diff.

           The get_token method supplied removes trailing whitespace from the key values before
           they are compared.

TODO

       Move intradiff functionality into VCS::Lite.

BUGS AND ENHANCEMENTS

       Please use rt.cpan.org to report any bugs in this module. If you have any ideas for how
       this module could be enhanced, please email the author, or post to the Wiki::Toolkit list
       (cgi (hyphen) wiki (hyphen) dev (at) earth (dot) li).

AUTHOR

       I. P. Williams (ivorw_openguides [at] xemaps {dot} com) The Wiki::Toolkit team
       (http://www.wiki-toolkit.org/)

COPYRIGHT

            Copyright (C) 2003-2004 I. P. Williams (ivorw_openguides [at] xemaps {dot} com).
            Copyright (C) 2006 the Wiki::Toolkit team (http://www.wiki-toolkit.org/)
            All Rights Reserved.

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

SEE ALSO

       VCS::Lite, Wiki::Toolkit, Wiki::Toolkit::Plugin, OpenGuides