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How to Write a WordPress Plugin – Introduction

How To Write a WordPress Plugin Series

This post was written as part of the How to Write a WordPress Plugin series.

For any WordPress user, plugins are essential. WordPress Plugins allow those with little to no programming skills to extend the functionality of their blog. Plugins come in all shapes and sizes, and there is a plugin that does just about anything for WordPress.

As good as WordPress is as a standalone application, there are still things that WordPress lacks. Users are requesting more and more features for WordPress that would be very feasible to write as a plugin. There are many untapped ideas out there, and new ones created every day.

Having released three plugins already (not counting the custom ones I wrote), I am aware of some of the limitations of WordPress and wish to share some of the lessons I have learned (and am still learning) about creating WordPress plugins. As a result, I will be starting series that will discuss various topics regarding writing your own WordPress plugin. The series will start off very introductory and will assume your plugin knowledge is zilch.

Who is this Series For?

This series is for any WordPress user who is curious about or wants to learn how to write their own WordPress plugin. Readers of this series will have an intermediate knowledge of PHP, know a little JavaScript, and be decent at Cascading Style Sheets.

This plugin series will benefit theme designers, those that like to tinker with plugin code, and those that are interested in writing their own plugin from scratch.

Tools to Get the Job Done

To write plugins, any text editor will do. Here are the tools I personally use to create plugins.

This series assumes you have WordPress 2.1.x or greater installed.

Code Samples

All code I use will be available for download after each post in the Conclusion section. I will be building the code as I go along, so each download will be different. I will be creating a plugin that doesn’t really do anything other than to show you the basics of how a plugin works.

Since each post in this series builds on top of each other, it is recommended to read this series in the order it is presented.

I highly recommend not using the test plugin on a production WordPress installation. Instead, use a local WordPress installation.

Topics

I plan to start off really basic and move quickly into the more hard-core WordPress plugin functions. This series will not be a comprehensive micro-detail of plugin development, but will hopefully give you a nice foundation to start your own plugin development. If you have any questions or suggestions, please leave a comment or e-mail me using the Devlounge contact form (Ronald). I do ask that you not rely on Devlounge for support and instead use the WordPress Support forums.

Techniques

Some of the techniques I use in my code samples may not be the best way to present code and you may be cringing because I don’t have a lot of shortcuts. I apologize in advance. Everybody has a different coding style.

As far as plugin techniques, structure, behavior, and other nuisances, if there is a better and easier way that I overlooked, I am all ears (er, eyes).

Series Publication Schedule

A post from this series is planned to be published every two days. To stay up to speed on the series, I suggest you subscribe to the Devlounge feed.

Conclusion

Thank you for reading the series introduction. My hope is that this series will prove beneficial to the readers. Any feedback is welcome. Thank you.


  1. By Robert posted on May 7, 2007 at 7:56 am
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    Great! I’m looking forward to this series because I love WordPress and am using it on 5 different sites. Especially if it will cover code I don’t know or did not find on the official site – like making my life easier or so :-)

  2. By Chris Huff posted on May 7, 2007 at 8:04 am
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    I too am looking forward to this series! My wife’s blog uses wordpress, and I may need to add a little functionality to make things easier for her.

  3. By Igor posted on May 7, 2007 at 8:34 am
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    Great initiative! I’ll follow this series with great interest!

  4. By inspirationbit posted on May 7, 2007 at 2:13 pm
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    This is the greatest series ever written on Devlounge! I’m looking forward to each of them. I’ve already printed the first two parts of the series and will be studying them very carefully.
    Thanks, Ronald!

    btw, Mac users can install MAMP that will quickly set you up with Apache/MySQL server and PHP.

  5. By Shawn Blanc posted on May 7, 2007 at 9:39 pm
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    Ron – This is great. I’m glad you’re going to be doing this. I’m looking forward to the series.

  6. By Ronald Huereca posted on May 8, 2007 at 12:26 am
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    Thank you to all who have expressed interest in the series. The series has been pre-written, so hopefully I will have covered enough ground to establish a foundation for your own plugin development.

    Plugin development is very intensive and I could very well write a book and not cover enough material.

    Thank you for your interest.

  7. By David Kierznowski posted on July 21, 2007 at 4:18 am
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    Ronald, you’ve put alot of work into this, great. I wrote a “How to write secure WordPress plugins” paper for blogsecurity.net. It may interest you on this projects (http://blogsecurity.net/wordpress/articles/article-280507/).

  8. By sorryle posted on December 23, 2007 at 11:22 pm
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    Thank you so much Ronald. I begin to learn how to write a wp plugin, this is a great start.

  9. By Pete posted on April 1, 2008 at 9:56 pm
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    I am trying to modify your plugin a little. I want it to display the author’s name and URL so readers can click on it. This is the code I have modified

    function addContent($content = ”) {
    $devOptions = $this->getAdminOptions();
    if ($devOptions[‘add_content’] == “true”) {
    $content .= “”.$devOptions[‘content’];
    $content .= ““.the_author().”“;
    }
    return $content;

    I can’t get WordPress to display the right URL. Any idea what I am doing wrong?

  10. By ralph dagza posted on August 17, 2008 at 12:46 pm
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    Please update the link, I moved the article to my new blog

    http://ralph.dagza.com/2008/08/how-to-install-wordpress-on-a-usb-stick/

    thanks for linking

  11. By Mark Phillips posted on September 27, 2008 at 11:55 am
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    Hi Ronald,
    Thank you very much for your tutorial. I have finally released our new plugin totally based on your tutorial. Without your tutorial it would have been a long and tough learning curve. Please check out the plugin http://www.dashboardzone.com/monitor-your-blog-goals-with-wordpress-plugin

    Thanks
    Mark

  12. By ymlove posted on February 12, 2009 at 4:05 am
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    can help me???source code plugin wordpress with database????

  13. By Pet Snakes posted on May 27, 2009 at 12:33 pm
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    Love your writing style and the design of your blog, its very original! Well done, look forward to reading more.

  14. By babu posted on June 20, 2009 at 10:09 pm
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    Hey Ron,

    I was wondering if you could hep me with a simple code for my plugin, I just started to develop one. All I want is to create a post and then add its link to my home page.

  15. By china wholesale posted on July 16, 2009 at 7:13 am
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    Can you provide more information on this?

  16. By John Bonds posted on July 19, 2009 at 4:47 pm
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    Thank you. I bookmark you blog!

  17. By Emily posted on July 29, 2009 at 8:28 am
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    Im having a lot of trouble with your blog loading lately. Intermittant, and goes to a page could not be found every so often. Hope there isnt any problems.

  18. By Radu posted on September 15, 2009 at 10:07 pm
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    Nice and straight introduction in wordpress plugins!
    Thanks… will make my development easier.

    Can you add also a tutorial explaining how one can debug a plugin using the tools that you mentioned?

  19. By learn css posted on September 16, 2009 at 8:16 am
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    Great Info…. Thanks

  20. By Eric Zhu posted on October 20, 2009 at 2:12 am
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    I think the comment may give me a good sense to know more about above subject.

  21. By wholesalers china posted on November 7, 2009 at 6:55 am
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    thanks, this is definitely what I need for my new website

  22. TrackbackHow to Write a WordPress Plugin SeriesHere is your del.icio.us goodness for 05-08 - mattherzberger.comDevlounge | Friday Focus #30HowTos zu Erstellung eines Wordpress Plugins | Bloganbieter.de Blog  Интересно почитать (15.05.2007) by Блог ДимкаWordPress PHP Programming » Getting started with WordPress PluginsWeblog Tools Collection » Blog Archive » Building your own Wordpress PluginWeblogToolsCollection Español » Blog Archive » Creando tu propio plugin de WordPress  Kendi wordpress eklentinizi yazın | BLOG KAZANI  Writing your own WordPress Plugin? by MeloVillareal.comQuick Links May 17¿Cómo crear un plugin para Wordpress? - Carrero Bitácora de los Hermanos Carrero, David Carrero Fernández-Baillo y Jaime Carrero Fernández-Baillo.Blog Roll España » Blog Archive » ¿Cómo crear un plugin para Wordpress?braindead1.de » Archiv » Devlounge Serie: How to write a Wordpress PluginYogaf.com » How to Write a WordPress PluginHow to Write a WordPress Plugin - interessante Beitragsserie at heimo’s blogPlugin für Wordpress Bastelanleitung - D-SIGN WeblogNimrodJO Blog | Internet & So Much More » Blog Archive » How To Write WordPress Plug-Ins SeriesDevlounge | Friday Focus #32When do you Consider you are a Successful Designer? » Inspiration Bittemporaneità : Post Updated NG 0.3 is outMy blog » Blog Archive » How to write a WordPress pluginTwelve Puzzle Pieces Of Writing A Series » Inspiration BitMark Kirby - Brighton » Blog Archive » links for 2007-06-06Building Wordpress Plugins - mattherzberger.comHow to Write a WordPress Plugin Series | Joomt» Como criar um plugin para WordPress Ganha dinheiro online com MUIOMUIO.NET: Internet, Tecnologia e dicas sobre Blogging por Mario AndradeWP Plugins DB » Plugin Details » Post Updated NGDr-Hamza’s SpaceLearning Things That Captivate » Inspiration BitPlugin für Wordpress Bastelanleitung - D-Sign WeblogCregy Web Development » Making a Wordpress Theme your own  Nasıl Wordpress Eklentisi Yazılır ? by # YaMTaR插件开发全攻略(目录) 于 Becomin' CharlesDas Wordpress Tutorial: Von der Installation bis Themes, Plugins und RSS20 Tutorials to Develop Wordpress Plugin | How-To | PelFusion.comWordPress Plugins20 Tutorials to Develop Wordpress Plugin « Pusat Tutorial Blog GratisHow to Write a WordPress Plugin Introduction Devlounge | Wood TV StandEssential Wordpress Plugin Development Resources, Tutorials and Guides : Speckyboy Design Magazine20 Tutorials to Develop Wordpress Plugin |