Tim TrottTim TrottDon't look back - you're not going that way

How To Create WordPress Widgets

By , Monday 20th April 2009 in WordPress

Wordpress plugins are pieces of addon code that extend the functionality of Wordpress, either behind-the-scenes or extra visual code. Widgets allow these code segments to be quickly and easily added to predefined sidebars on most themes.

This article refers to old versions of WordPress. For an up to date guide for the most recent versions (2.8+) please see this article - How To Create Widgets for WordPress 2.8

Before WordPress version 2.0, these extra visual plugins had to be hand coded into the theme template, so knowledge of PHP was required. In version 2.0 they introduced "Widgets" which wrap around a plugin and allow a non code editing method for incorporating into a theme using sidebars and a drag and drop interface.

This tutorial covers creating a Widget, creating a plugin widget, adding sidebars to a theme, and upgrading a non-widget plugin.

Creating a Simple WordPress Plugin

You can use this as a code snippet for your projects. I am going to create a simple plugin that does nothing but display "Hello World". I'll leave the actual functionality of the plugin to you  ;) 

Create a new php file in your plugin directory called my-hello-world.php, and type the following plugin code:

<?php
/*
Plugin Name: Hello World
Plugin URI: http://timtrott.co.uk/
Description: Sample Hello World Plugin
Author: Tim Trott
Version: 1
Author URI: http://timtrott.co.uk/
*/
 
function sampleHelloWorld() 
{
  echo "<h2>Hello World</h2>";
}
?>
 

The lines inside /* and */ are used by WordPress to find out about the plugin. We have one function called sampleHelloWorld which does exactly that.

Now, traditionally we would have had to open up the sidebar of the theme you are using, find the location of where you want the Hello World displayed, and hard code the function in. Upload to the server and test. If for some reason there is a problem with your plugin (or a third party plugin) then your site would almost certainly stop working. Changing the location from the left to the right sidebar means editing both files accordingly. This isn't very good.

Widgets

Widgets take away the need for editing the sidebar files of a theme and allow for a drag and drop interface in the admin panel. Let's have a look at how we can widget enable our plugin.

Open up the Hello World plugin file again and add these lines:

 
function widget_myHelloWorld() {
?>
  <h2 class="widgettitle">My Widget Title</h2>
  <?php sampleHelloWorld(); ?>
<?php
}
 
function myHelloWorld_init()
{
  register_sidebar_widget(__('Hello World'), 'widget_myHelloWorld');     
}
add_action("plugins_loaded", "myHelloWorld_init");
 

The first function here is what will be displayed on the sidebar when its set-up correctly. Notice that we are calling on our old function. This is upgrading the existing plugin to be widget enabled. You can if you like replace the function call with the function statements and combine the two functions.

The second function is called by WordPress when the plugin is activated. It calls a WordPress function that will register a new widget which will be called "Hello World" which will call our new widget function.

Add action just tells WordPress to call myHelloWorld_init when the plugin is loaded.

Enhancements for Theme Compatibility

While this widget will function fine, we can make some improvements to enable greater theme compatibility - not everyone uses the same themes as you test on.

WordPress will pass parameters to your widget, which contain information about the sidebar and the CSS classes. We should process these parameters and output the correct tags, or you risk breaking some themes.

The first thing we need to do is change our sampleHelloWorld function so that it will accept parameters, then to process these parameters into variables. This is done using the extract function.

 
function widget_myHelloWorld($args) {
  extract($args);
?>
  <h2 class="widgettitle">My Widget Title</h2>
  <?php sampleHelloWorld(); ?>
<?php
}

These two lines will allow us to reference some variables and output correct html structure for the theme being used. The most important variables are before_widget, after_widget, before_title and after_title. Previously we have surrounded the widget title with a hard coded H2 tag with a css class widgettitle, but many themes do not support these tags. They may use a div, or a h1 or a span, so we need our widget to be flexible.

 
function widget_myHelloWorld($args) {
  extract($args);
  echo $before_widget;
  echo $before_title;?>My Widget Title<?php echo $after_title;
  sampleHelloWorld();
  echo $after_widget;
}

These changes will allow our plugin to use the same tags as the theme author informs us we need to use, and will allow your widget to look the same as the other widgets in the sidebar.

To configure these options inside a theme, please see the section below on theme support.

Complete Plugin:

<?php
/*
Plugin Name: Hello World
Plugin URI: http://timtrott.co.uk/
Description: Sample Hello World Plugin
Author: Tim Trott
Version: 1
Author URI: http://timtrott.co.uk/
*/
 
function sampleHelloWorld() 
{
  echo "<h2>Hello World</h2>";
}
 
function widget_myHelloWorld($args) {
  extract($args);
  echo $before_widget;
  echo $before_title;?>My Widget Title<?php echo $after_title;
  sampleHelloWorld();
  echo $after_widget;
}
 
function myHelloWorld_init()
{
  register_sidebar_widget(__('Hello World'), 'widget_myHelloWorld');     
}
add_action("plugins_loaded", "myHelloWorld_init");
?>
 

Testing your Plugin

If you check your plugins page now, you should now have a new plugin listed called Hello World which you can activate. On the Presentation tab, select widgets, and you should see your new widget available to be dragged onto a sidebar. Save your changes and admire your new work.

WordPress Widget listed as installed
WordPress Widget listed as installed

Stop! My Theme Doesn't Support Widgets!

If your theme does not have widget enabled sidebars, this little tutorial will help make it widget enabled. I am using a very basic sidebar theme, most sidebars are a little more complex than this.

 
<div id="sidebar">
  <ul>
    <?php if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar() ) : ?>
      <?php wp_list_pages('title_li=<h2>Pages</h2>' ); ?><br/>
      <li><h2>Archives</h2>
        <ul>
          <?php wp_get_archives('type=monthly'); ?>
        </ul>
      </li>
      <?php wp_list_categories('show_count=1&amp;title_li=<h2>Categories</h2>'); ?>
    <?php endif; ?>
  </ul>
</div>
 

The first of these lines does an if else statement, if we have a sidebar function call it otherwise we do the existing hard coded sidebar.

The second line (endif) tells the if statement where the hard coded sidebar ends. Anything between the first and second lines will be shown if widgets are disabled or no widgets are assigned to the sidebar.

Before you can add a widget to this sidebar, we need to make WordPress aware of it by registering it.

Open, or create, functions.php in your theme folder, and find (or add) a line like this:

 
<?php
if ( function_exists('register_sidebars') )
    register_sidebars(1);
?>
 

Where the parameter to register_sidebars is the number of sidebars defined in your theme. You can have any number of sidebars. Now you will be able to add widgets to your sidebar.

Should you wish to configure the elements that will appear before and after a widget, or the tags that a widget title will appear in, you can setup the options array and pass it to the register_sidebar function.

register_sidebar(array(
'before_widget' => '<li>',
'after_widget' => '</li>',
'before_title' => '<div class="sidebar_title">',
'after_title' => '</div>',
));

This will cause the widget to be contained within <li></li> tags and the widget title will be in a div with the css class sidebar_title.

As with most programming and development, there are a number of different methods of obtaining the same results, the techniques listed here are just what works for me.

You may also be interested in reading how to create control panels for your widgets.

My website and its content are free to use without the clutter of adverts, tracking cookies, marketing messages or anything else like that. If you enjoyed reading this article, or it helped you in some way, all I ask in return is you leave a comment below or share this page with your friends. Thank you.

About the Author

Tim Trott

Tim is a professional software engineer, designer, photographer and astronomer from the United Kingdom. You can follow him on Twitter to get the latest updates.

Further Reading
97 thoughts on “How To Create WordPress Widgets”
  1. Gravatar
    Free Psychic Readings – Go!

    Hello, just wanted to say, I loved this astrology post.
    It was practical. Keep on posting!

  2. Gravatar
    Andrew

    Thanks for tutorial! I never attempted to write a plugin before for a fear it would be too complicated.. Now I shall try!  :) 

  3. Gravatar
    otenyano

    The plugin works. But I can only use the widget one time. How to make it usable on more sidebars?

    1. Tim Trott
      Tim Trott

      This article refers to old versions of WordPress. For an up to date guide for the most recent versions (2.8+) please see this article – http://timtrott.co.uk/creating-widgets-wordpress/

  4. Gravatar
    Alok Ranjan Dubey

    Thanks,I get a good knowledge about your right instruction.

  5. Gravatar
    mahmud

    thanx for informative post. i am a newbie to php and do not follow the array, argument etc functions. Please write a tutorial on how to create a simple widget which i can place anywhere in my theme using div tag. Thanks in advance.

  6. Gravatar
    alan

    Excellent! Thanks for this .. exactly what I was looking for!!

  7. Gravatar
    Amitabha Roy

    The tutorial is small and best. I have learnt widget creation very quickly from here. Thanks.

  8. Gravatar
    satish

    Awesome article.. thanks a lot.

  9. Gravatar
    Raul Singh

    Thanks Buddy,
    A very well written article. Cheers..keep the good work...

  10. Gravatar
    Todd M.

    Love this. Thank you for the info.

  11. Gravatar
    ibnu

    thanks, nice info...

    i just learn create plugin that contain widget....

  12. Gravatar
    Udar Gromov

    2012-01-31 TUE 13:40
    First time ever I am leaving a comment!
    Because, this is a pure gold!
    I was able to create my Plug-in in minutes.
    This not only usable, by educational!
    Especially valuable for me was Summary.

    Fantastic! Thank you for your style of presenting!
    As a courtesy to readers, I ran a spell check on my message.

  13. Gravatar
    Tim Love

    This is an excellent article. As someone who has no programming skills, but loads of ideas for wordpress plugins; which is the best place for me to go to be able to hire someone with suitable skills to be able to do the programming for me?

  14. Gravatar
    Shaile

    Hi ,

    Thanks to help us.
    It's great and very easy way to make a wedget thanks a lot....:)

  15. Gravatar
    Wingman

    Thank you very much for the post! Simple and clear! Just great!

  16. Gravatar
    relisys

    Tim Trott you are absolutely awesome! I have been trying to get this solution for 4 days straight and no one on irc or anywhere else could help me.

    Many thanks !!!!! Thank you Thank you Thank you.!!

  17. Gravatar
    SAMsan

    Awesomeness !

  18. Gravatar
    Steven Ferrino

    Thanks Tim, this just saved me a bunch of time.

  19. Gravatar
    DavidM

    Thank you much. I'm working on a plugin right now using this base and hopefully will get it released very soon.

  20. Gravatar
    Cairns Diver

    Thanks for the tutorial, I was trying to find a way to convert mt plugin into a widget for the sidebar.

  21. Gravatar
    Chad Huntley

    Thanks for this tutorial, it was very helpful in developing a new widget for BuddyPress!

  22. Gravatar
    IWM – Marketing Internet

    Tim, with your help I created my first widget ever!

    Thanks a lot man

  23. Gravatar
    Deep C

    Simple and Superb !!
    Thanks.

  24. Gravatar
    DesignMango

    Nice tutorial thanks

  25. Gravatar
    Towfiq I.

    simple and awesome. Thank you so much for this post  :D 

  26. Gravatar
    Orion

    I've followed the tutorial here, & while the widget appears in the plugins list (which I've activated), my activated plugin doesn't show in the Appearance->Widgets list.

    Might you know why?

    - O8

  27. Gravatar
    Prasath

    Thank You very much!!!

  28. Gravatar
    Leyton Jay

    This is shockingly awesome.
    Can't believe it was so easy, I would've started doing this years ago if I'd known!

    Cheers mate.

  29. Gravatar
    purwa

    wow great! ,this was exactly the solution I was looking for. Thanks alot!

  30. Gravatar
    Jeff

    Thank you very much for taking the time to create and share this. With the release of WP 3.0 I'm stepping more into the programing side of WP as I create a custom post type. This is a perfect tutorial for getting me started with Widgets as I wanted a way to display custom post type output in a widget. Thanks!

  31. Gravatar
    Dhinakran

    Nice and smart for the plugin creators

  32. Gravatar
    Y.Y.W.

    Great tutorial! Thanks for taking the time and post this article. I have bookmarked this post so I can always come back for reference.

    Thanks!

  33. Gravatar
    MySelf_v1

    Is it possible to use JavaScript for the Widget?

  34. Gravatar
    cathy2005

    Is it possible to add a widget programmatically so that the user does not have to Drag/Drop?

  35. Gravatar
    droid free apps

    sweet, I have to create my own widget some a site am working on..

  36. Gravatar
    Clover

    GEATE ! ! ! !

    Getting this helpful suggestion, I could alive my PHP code as widgets.

    Thank you!!!!

  37. Gravatar
    mona

    thank.It help me to make my plugin..

  38. Gravatar
    Dan

    Really impressive - very simple but very helpfull. Thanks!

  39. Gravatar
    djole

    Very useful article. I am ready to create my personal plugin.
    Thank you.

  40. Gravatar
    Glenn

    Tim,

    Nice tutorial. After doing this over and over again I created to tool to take the tedium out of creating WordPress Widgets. Take a look over at http://www.widgetifyr.com and let me know what you think.

    Glenn

  41. Gravatar
    Angelika

    This was EXACTLY what I needed. Thank you.

  42. Gravatar
    Conrad

    Really appreciate this tutorial. Nicely done - simple, quick and to the point. Nicely done.

  43. Gravatar
    Neeraj Kumar

    This is a very good example. Since I come from a C++ background, it helped e a lot.

    Thanks again!

  44. Gravatar
    Christher Lenander

    Thank you. This is what I been looking for. lots of articles about creating plugins but few about creating widgets.

  45. Gravatar
    Pinyo

    Really excellent tutorial. I appreciate it! Definitely cut my development time in half.

  46. Gravatar
    Kaitora

    Your plugin has been a great help for me to learn how to create some wordpress plugins. All of the other tutorials I have seen have not included anything on widgets. Thanks for the wonderful resource

  47. Gravatar
    jim smith

    Thanks for the hello world style example.
    it was the best example i have found yet.

  48. Gravatar
    KreCi

    Thanks man! That is so helpful! You will see my new widget plugin released soon!
    Happy New year 2010!  :) 

  49. Gravatar
    BrandonSch

    Great post , You've really hit the
    nail on the head, I just don't understand why people quite get it.
    I'm not for sure how many people I've talked to concerning this very
    thing in the past month, and they just can't get it.

    , Excellent post!

  50. Gravatar
    Mauricio Wolff

    Man... a lifesaver.

    Thanks a lot. This tutorial and the plugin "TS Custom Widgets" (that allows me to select wich widget should show on each page/post) makes wordpress even better.

    Tks a lot

  51. Gravatar
    Pravin

    @Uppfinnarn, @Stubbornella: The tags aren't mixed up. They are intented that way.

    Instead of using echo $before_title . 'My Widget Title' . $after_title;

    the author should have used
    echo $before_title;?>My Widget Title<?php echo $after_title;

    1. Gravatar
      Pravin

      Oops, the two code lines should be switched.

    2. Gravatar
      MasterCJ

      Derp, they do the same thing genius. Take a look at the generally used wordpress code conventions sometime and you'll see that the way he did it was far from uncommon.

  52. Gravatar
    Markus Freise

    Great tutorial to learn first steps. Thank you.

  53. Gravatar
    Uppfinnarn

    There are <strong> tags in some of the latter examples; looks weird...

  54. Gravatar
    Gopinath

    Thank for your widget creation step by step explaination,its really awesome,,.

  55. Gravatar
    manitra

    Hello,

    Thanks for this tutorial, it's an excellent starting point.

    Manitra.

  56. Gravatar
    chocobee

    thanks for the tutorial. do u know any link that teach how to create advance widget?

  57. Gravatar
    Stubbornella

    There are a couple of places where the tag got mixed in with your php.

  58. Gravatar
    Vinicius

    Greate tuto....

    Tks

  59. Gravatar
    jigar

    really verry nice article for beginners and its working fine.... thanks ...

  60. Gravatar
    Christian

    Great article/tutorial

    How about writing about how to make options/settings for a widget. Thar would really be helpful...

  61. Gravatar
    kelik

    Thanks..

  62. Gravatar
    Aod

    I'm trying to create a sidebar widget using the code at http://www.stopie6.com/widgets.html (Simple Text Message), but can't work out which code to change in your example, and where to put the code in from the link? How would the php file handle that if statement?

    1. Gravatar
      Glenn

      Aod,

      You might want to try my tool over at widgetifyr.com. It wraps code into a WordPress widget.

  63. Gravatar
    Njualem

    Excellent and Cristal-Clear, I can now get into making widgets for my website.

    Thanks a Million.

  64. Gravatar
    Dimitar Stoyanov

    Great article! Really good introduction to widget basics.

    software_developer: thank for the nice link. Really helpful information about widget's setup!

  65. Gravatar
    seo free

    Thanks really helpful to create a plugin for wordpress..thanks lot..:)

  66. Gravatar
    James

    I just created a Google Translate widget for my blog and it only took a few minutes thanks to your introduction. Thanks!

  67. Gravatar
    Aakash

    Thanks very much. This is the thing i want !

  68. Gravatar
    Jonathan Drain

    Great article! I found it very straightforward and helpful.

  69. Gravatar
    Ian Kree

    Nice article. It tells exactly what I need to do.

  70. Gravatar
    Abi

    What a simple solution to my problem. I do not know php but is right away going to try this simple methid to make extra widgets for my blog.
    Thanks!

  71. Gravatar
    gercek

    better than wordpress documentation. thanks.

  72. Gravatar
    Davis

    I dont get any of the mubble jummble! please help me in a simple way!!!

  73. Gravatar
    Phoenix

    Hello sir, i have a question. How can i create a title field for the widget so the user can rename it with whatever they like. I really blind about php and WordPress coding. So could you tell me the code and where to place it. Don't worry i can figure it out. Thanks:).

  74. Gravatar
    Björn

    Thanx a lot for this nice tutorial ... !!!

    Merry Christmas from Germany...

  75. Gravatar
    Jeff R.

    I am a little confused by this line;

    &lt?php echo $after_title;

    Is that supposed to be an actual less than bracket, making an opening php tag?

    And, I thought when I started reading this that the Hello World example was just to show you the initial step. What is the purpose of it being called later in the function? I thought for an instant maybe we were supposed to put HTML in there, but you have the widget tags to use what the user theme has already...

    Confused....

    1. Tim Trott
      Tim Trott

      You are correct about the php tag, it got converted to html chars along the way  :( 
      Not sure quite what you mean about calling the function? I guess your referring to the call to sampleHelloWorld() from within widget_myHelloWorld($args)? This is just to keep the different sections code separate. You can replace sampleHelloWorld() with whatever you wish.

      HTH

  76. Gravatar
    My Puppy654

    uhhh..... i don't get it! It looks to complicated! I thought it would be easy but i guess not..... i was planning on making a widget but now i guess not....  :( 

  77. Gravatar
    stratosg

    excellent man! very very very helpful thanks!

  78. Gravatar
    Rana

    Very nice article. Thanks

  79. Gravatar
    nkuttler

    Great article, thanks! I've already written plugins but never before a widget. This and your post about how to create control panels for widgets are very useful.

  80. Gravatar
    Awshaal

    Thank you so much, such wonderful article.. A++++

  81. Gravatar
    Anonymous

    Really Nice guide to aadd widgets

  82. Gravatar
    chat

    thanks for all..

  83. Gravatar
    Fareeha

    Thanks a bunch for the help.

  84. Gravatar
    palPalani

    thanks for you information, this is what i&squot;m looking for... great!

  85. Gravatar
    McLarty

    Thanks for the great &quot;hello-world&quot; ...I&squot;m just getting started on a plugin!

    got any good links to the next steps? Eg. Calling a flash movie or creating options inside of WordPress for the plug-in?

  86. Gravatar
    don

    Thx!! A nice and easy to follow explanation!

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