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. <
|<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