CGI::Kwiki(3) A Quickie Wiki that's not too Tricky

KWIK START

The Offficial Kwiki Home is at http://www.kwiki.org. This site is a Kwiki itself. It contains much more information about Kwiki than the distributed docs.

DESCRIPTION

A Wiki is a website that allows its users to add pages, and edit any existing pages. It is one of the most popular forms of web collaboration. If you are new to wiki, visit http://c2.com/cgi/wiki?WelcomeVisitors which is possibly the oldest wiki, and has lots of information about how wikis work.

There are dozens of wiki implementations in the world, and many of those are written in Perl. As is common with many Perl hacks, they are rarely modular, and almost never released on CPAN. One major exception is CGI::Wiki. This is a wiki framework that is extensible and is actively maintained.

Another exception is this module, CGI::Kwiki. CGI::Kwiki focuses on simplicity and extensibility. You can create a new kwiki website with a single command. The module has no prerequisite modules, except the ones that ship with Perl. It doesn't require a database backend, although it could be made to use one. The default kwiki behaviour is fairly full featured, and includes support for html tables. Any behaviour of the kwiki can be customized, without much trouble.

EXTENDING

CGI::Kwiki is completely Object Oriented. You can easily override every last behaviour by subclassing one of its class modules and overriding one or more methods. This is generally accomplished in just a few lines of Perl.

The best way to describe this is with an example. Start with the config file. The default config file is called "config.yaml". It contains a set of lines like this:

    config_class:      CGI::Kwiki::Config
    driver_class:      CGI::Kwiki::Driver
    cgi_class:         CGI::Kwiki::CGI
    cookie_class:      CGI::Kwiki::Cookie
    database_class:    CGI::Kwiki::Database
    metadata_class:    CGI::Kwiki::Metadata
    display_class:     CGI::Kwiki::Display
    edit_class:        CGI::Kwiki::Edit
    formatter_class:   CGI::Kwiki::Formatter
    template_class:    CGI::Kwiki::Template
    search_class:      CGI::Kwiki::Search
    changes_class:     CGI::Kwiki::Changes
    prefs_class:       CGI::Kwiki::Prefs
    pages_class:       CGI::Kwiki::Pages
    slides_class:      CGI::Kwiki::Slides
    javascript_class:  CGI::Kwiki::Javascript
    style_class:       CGI::Kwiki::Style
    scripts_class:     CGI::Kwiki::Scripts

This is a list of all the classes that make up the kwiki. You can change anyone of them to be a class of your own.

Let's say that you wanted to change the BOLD format indicator from "*bold*" to '''bold'''. You just need to override the "bold()" method of the Formatter class. Start by changing "config.yaml".

    formatter_class: MyKwikiFormatter

Then write a module called "MyKwikiFormatter.pm". You can put this module right in your kwiki installation directory if you want. The module might look like this:

    package MyKwikiFormatter;
    use base 'CGI::Kwiki::Formatter';

    sub bold {
        my ($self, $text) = @_;
        $text =~ s!'''(.*?)'''!<b>$1</b>!g;
        return $text;
    }

    1;

Not too hard, eh? You can change all aspects of CGI::Kwiki like this, from the database storage to the search engine, to the main driver code. If you come up with a set of classes that you want to share with the world, just package them up as a distribution and put them on CPAN.

By the way, you can even change the configuration file format from the YAML default. If you wanted to use say, XML, just call the file "config.xml" and write a module called "CGI::Kwiki::Config_xml".