Django (web framework)


Django (web framework)
Django
Django logo.svg
Django default page.png
The default Django page
Developer(s) Lawrence Journal-World
Initial release July 21, 2005 (2005-07-21)
Stable release 1.3 / March 23, 2011; 7 months ago (2011-03-23)
Preview release 1.3 RC1 / March 3, 2011; 8 months ago (2011-03-03)
Written in Python
Type Web application framework
License BSD License
Website djangoproject.com

Django (play /ˈæŋɡ/ jang-goh)[1] is an open source web application framework, written in Python, which follows the model-view-controller architectural pattern.[2] It was originally developed to manage several news-oriented sites for The World Company[3] of Lawrence, Kansas, and was released publicly under a BSD license in July 2005; the framework was named after guitarist Django Reinhardt.[4] In June 2008 it was announced that a newly formed Django Software Foundation will take care of Django in the future.[5]

Django's primary goal is to ease the creation of complex, database-driven websites. Django emphasizes reusability and "pluggability" of components, rapid development, and the principle of DRY (Don't Repeat Yourself). Python is used throughout, even for settings, files, and data models.

Django also provides an optional administrative CRUD (create, read, update and delete) interface that is generated dynamically through introspection and configured via admin models.

Contents

Components

Screenshot of the Django admin interface for modifying a user.

The core Django MVC framework consists of an object-relational mapper which mediates between data models (defined as Python classes) and a relational database ("Model"); a system for processing requests with a web templating system ("View") and a regular-expression-based URL dispatcher ("Controller").

Also included in the core framework are:

  • A lightweight, standalone web server for development and testing.
  • A form serialization and validation system which can translate between HTML forms and values suitable for storage in the database.
  • A caching framework which can use any of several cache methods.
  • Support for middleware classes which can intervene at various stages of request processing and carry out custom functions.
  • An internal dispatcher system which allows components of an application to communicate events to each other via pre-defined signals.
  • An internationalization system, including translations of Django's own components into a variety of languages.
  • A serialization system which can produce and read XML and/or JSON representations of Django model instances.
  • A system for extending the capabilities of the template engine.
  • An interface to Python's built-in unit test framework.

Bundled applications

The main Django distribution also bundles a number of applications in its "contrib" package, including:

  • An extensible authentication system.
  • The dynamic administrative interface.
  • Tools for generating RSS and Atom syndication feeds.
  • A flexible commenting system.
  • A sites framework that allows one Django installation to run multiple websites, each with their own content and applications.
  • Tools for generating Google Sitemaps.
  • Tools for preventing cross-site request forgery.
  • Template libraries which enable the use of lightweight markup languages such as Textile and Markdown.
  • A framework for creating GIS applications.

Applications built on Django

  • django CMS, a free and open source[6] content management system platform for publishing content on the World Wide Web and intranets. [7], and written in Python[8].
  • The Pinax framework provides reusable applications aimed at Django-based social networking websites.
  • RapidSMS is a framework for SMS applications built on Django.
  • Pootle is an online translation management tool.
  • Review Board is a web-based code review tool.
  • Rietveld is another web-based code review tool built on Django. It was originally written to serve as a showcase for using Django with Google App Engine.[9]
  • Disqus uses Django for their widely popular discussion platform.
  • Spotify uses Django for some of their web sites.
  • Yandex uses Django for their weather forecast site, OpenID provider, blog hosting service, internal Wiki and internal Mail Archives.
  • Transifex – an open source platform for localization.
  • Bucketlist – uses Django to let users store life goals.
  • The Public Broadcasting Service in the United States uses Django for some of their web sites.[10]
  • The Berkeley Graduate School of Journalism uses Django for their websites.[11]
  • The Faculty of Electrical Engineering and Information Sciences at the Ruhr University Bochum uses Django for their website.[12]
  • Universal Subtitles uses Django for its free and open source collaborative subtitling site.
  • FreeNAS uses Django for its web interface in its newest major release, 8.0.
  • Djangosites.org uses Django for handling its huge python powered sites directory.

Server arrangements

Django can be run in conjunction with Apache using mod_wsgi or mod_python. Django also includes the ability to launch a FastCGI server, enabling use behind any web server which supports FastCGI. Another deployment option is nginx and uwsgi. It should also be possible to use other WSGI-compliant web servers. Django officially supports four database backends: PostgreSQL, MySQL, SQLite and Oracle. MS SQL backend can be used with django-mssql but only in Microsoft operating systems, similarly external backends exist for IBM DB2 , SQL Anywhere and Firebird. There is a fork named django-nonrel which supports NoSQL databases like MongoDB and Google App Engine's Datastore.

Django may also be run in conjunction with Jython on any Java EE application server such as GlassFish or JBoss. In this case django-jython must be installed in order to provide JDBC drivers for database connectivity, which also provides functionality to compile Django in to a .war suitable for deployment.

Versions of Django prior to 1.0 had multithreading issues [13] and it would be recommended that those versions of Django only be used in a single threaded server configuration, such as with Apache prefork MPM using mod_python or embedded mode of mod_wsgi. Although Django 1.0 is principally believed to now be thread safe, some minor threading issues are still occasionally being found; it may be prudent to continue to use a single threaded server configuration and/or stay current with Django releases and notices about the multithreading issues. [13]

Google App Engine includes Django 0.96.1[14] as one of the bundled frameworks.

Integrated development environments

While a number of Django developers use text editors such as VIM, Emacs or TextMate with Django Bundle for their projects, the other prefer more specialized tools providing intellisense, code completion, debugging, refactoring, unit testing, etc.[15]

DjangoCon

There is a twice-yearly conference for Django developers and users, named "DjangoCon", that has been held since September 2008. One DjangoCon a year is held in Europe, in May or June;[17] while the other is held in the United States in September, usually in Portland, Oregon.[18].

Books

  • The Definitive Guide to Django (Apress) - first edition December 2007, second edition July 2009. Released under the GNU Free Documentation License.[19] Available online for free at www.djangobook.com.
  • Practical Django Projects by James Bennett (Apress) - first edition June 2008, second edition June 2009.[20]
  • Pro Django by Marty Alchin (Apress) - December 2008.[21]
  • Python Web Development with Django by Jeff Forcier, Wesley Chun, and Paul Bissex (Addison-Wesley) - November 2008.[22]

See also

References

  1. ^ What does “Django” mean, and how do you pronounce it?
  2. ^ Django FAQ about MVC in Django
  3. ^ LJWorld.com / About us
  4. ^ "Django FAQ". Lawrence Journal-World. http://www.djangoproject.com/documentation/faq/. Retrieved 2008-04-01. 
  5. ^ Announcing the Django Software Foundation
  6. ^ "Developers". django-cms.org. http://www.django-cms.org/en/developers/. Retrieved 2009-09-22. 
  7. ^ "Django CMS Apps Comparison". djangoproject.com. http://code.djangoproject.com/wiki/CMSAppsComparison. Retrieved 2009-11-17. 
  8. ^ "Languages used by Django CMS". github.com. http://github.com/divio/django-cms/graphs/languages. Retrieved 2009-11-17. 
  9. ^ CodeReviewBackground – rietveld – Background of the CodeReview (Rietveld) project. – Project Hosting on Google Code. Code.google.com. Retrieved on 2010-12-30.
  10. ^ "20 Creative Websites Running Django". http://fearlessflyer.com/2009/11/20-creative-websites-running-django/. 
  11. ^ "Webcasting with Django". Berkeley Graduate School of Journalism. 2009-05-20. http://multimedia.journalism.berkeley.edu/blog/2009/may/20/webcasting-django/. 
  12. ^ [1] Faculty of Electrical Engineering and Information Sciences at the Ruhr University Bochum
  13. ^ a b DjangoSpecifications/Core/Threading – Django – Trac. Code.djangoproject.com. Retrieved on 2010-12-30.
  14. ^ Running Django on Google App Engine – Google App Engine – Google Code. Code.google.com (1999-02-22). Retrieved on 2010-12-30.
  15. ^ Django development IDEs discussion at Stackoverflow
  16. ^ NetBeans Django Plugin
  17. ^ DjangoCon EU series, Lanyrd.com
  18. ^ DjangoCon US series, Lanyrd.com
  19. ^ The Definitive Guide to Django: Web Development Done Right, Second Edition : 9781430219361. Apress.Com. Retrieved on 2010-12-30.
  20. ^ Practical Django Projects, Second Edition : 9781430219385. Apress.Com. Retrieved on 2010-12-30.
  21. ^ Pro Django : 9781430210474. Apress.Com. Retrieved on 2010-12-30.
  22. ^ Pearson – Python Web Development with Django – Jeff Forcier, Paul Bissex & Wesley Chun. Pearsonhighered.com (2008-10-24). Retrieved on 2010-12-30.

Bibliography

External links


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