Catalyst (software)

Source: Wikipedia, the free encyclopedia.
Catalyst
Original author(s)Sebastian Riedel
Stable release
5.90130 / 9 November 2022; 17 months ago (2022-11-09)[1]
Written in
GPL
Websitehttp://catalyst.perl.org/

Catalyst is an

Spring
.

Catalyst can be used by web application developers to deal with code common to all web applications. It provides an interface for receiving page requests, dispatching page requests into developer-written code to process, and return of the requests. Catalyst also provides a standardised interface for data models, authentication, session management and other common web application elements.

All of these elements are implemented as plugins to a set of common interfaces, allowing the developer to change the specific method used (e.g. a session storing in shared memory versus as a database table, or using FastCGI versus operating as an within Apache's mod_perl) by changing the configuration of Catalyst to use a different plugin without altering the application code.

Catalyst is primarily distributed through the CPAN, which is the official distribution channel for Perl libraries and applications.

History

Maypole was one of the first web application frameworks for the Perl programming language that was based on the

MVC pattern; its principal author was Simon Cozens.[2] Catalyst started as a fork of Maypole, intended to become Maypole 3.0.[3] Development ceased on Maypole, however, with its most recent release in April 2008,[4]
and Catalyst became its modern supported equivalent.

The first development release of Catalyst took place on 28 January, 2005. The first official version was published on CPAN on February 16, 2005.[5] As of June 2011, Catalyst had 201 registered contributors.[6]

Philosophy

Catalyst is based on the "don't repeat yourself" (DRY) principle, which means that definitions should only have to be made once. Catalyst can be used with automatic class loading from the database through one of the many loader modules, thus requiring no code for the database layer. But, if you require the flexibility of manually doing everything, it's also an option. Another guiding principle of Catalyst is flexibility.

Catalyst promotes the re-use of existing Perl modules that already handle common web application concerns well.

  • The Model part is handled through DBIx::Class, Plucene, Net::LDAP and other model classes.
  • The View layer is usually handled by Template Toolkit, Mason, or HTML::Template, among others.
  • The Controller layer is of course written by each application author. Large chunks of Controller functionality can usually be deferred to one of the many Catalyst plugins (e.g., Catalyst::Plugin::FormValidator, Catalyst::Plugin::Prototype, Catalyst::Plugin::Account::AutoDiscovery, etc.).
  • Finally, Catalyst offers a set of helpers to simplify flow control and mapping URLs to controller methods.

Catalyst has a large selection of plugins.

Ajax framework
). Plugins cover many areas, for example authentication, session management, HTTP negotiation and REST.

Catalyst can also be used with other Ajax frameworks such as jQuery or YUI, the Yahoo! User Interface Library.

Web server support

For development and testing, Catalyst has a built-in simple HTTP server. For production use,

Cherokee or Nginx with FastCGI or mod_perl
support is recommended, but any web server with CGI or FastCGI support will work. On Apache, mod_perl can help with performance considerably, though its use might be an issue because it can be unsafe to share multiple applications under mod_perl.

Since early 2008, Catalyst applications can also be deployed using the HTTP::Prefork engine

PSGI spec thus it can be run on any Plack server and along with any server or protocol that supports the PSGI spec, including Mongrel2
.

Database support

Catalyst can run using any database supported by

Oracle and Microsoft SQL Server. For ODBMSes, there is explicit support for KiokuDB via Catalyst::Model::KiokuDB.[9] The Model abstraction allows databases of any nature to be accessed via Catalyst::Model::Adaptor.[10]

Many Catalyst-based projects use

ORM layer
, which provides further abstraction of SQL queries, using a resultset-based API with transparent support for arbitrary joins and other features.

Uses

Websites powered by Catalyst include Magazines.com,[11] bbc.co.uk iPlayer backend,[12] DuckDuckGo's Community Platform, http://flexibase.io and Tripwolf.com. The MojoMojo wiki engine is written using Catalyst.[13]

YouPorn was powered by Catalyst[14] until 2012.[15]

See also

References

  • Diment, Kieren. The Definitive Guide to Catalyst. Apress.
    ISBN 978-1-4302-2365-8. Archived from the original
    on 2009-09-17. Retrieved 2009-09-09.

External links