Post-Plugin Library


Unfortunately, due to ill-health, this plugin has not been developed or supported properly for some years. It works with the latest versions of WordPress (including on this website) but could possibly conflict with any WordPress features added after 2008 — e.g. custom post types — if you use them.


This plugin provides a library of essential routines for the Post Plugins: Similar Posts, Recent Posts, Random Posts, Popular Posts, and Recent Comments. It does nothing on its own but is required if you use the other plugins.

This is version download latest version. It is compatible with WordPress 1.5–2.6.2.

Installation Instructions

  1. If upgrading from a previous version, first deactivate the plugin via the Plugins page and delete the plugin folder from your server.
  2. Upload the plugin folder to your /wp-content/plugins/ directory.


  • 1. Mattias  |  May 20th, 2008 at 6:36 am

    Thanks! Works like a charm šŸ™‚

  • 2. Rob  |  June 4th, 2008 at 10:42 am

    If you had the misfortune to download version you may run into problems when you try to update to a newer version. I managed to introduce a circular dependence between this plugin and the Post Plugins which means trying to update either from the admin plugins page will cause an error. Instead you need to delete the version from the server and upload the newer one and the problem should be solved. I apologise for any worry or inconvenience.

  • 3. Mohamad  |  June 4th, 2008 at 12:24 pm

    Hello Rob first i would like to thank you for your great plugins which made wordpress more easy and fun šŸ™‚ Today after i updated (post-plugin-library) from to i got this error ?

    Warning: Invalid argument supplied for foreach() in /homepages/13/d239009630/htdocs/wp-content/plugins/post-plugin-library/common_functions.php on line 248

    None Found

    if you have any idea how i can fix it? also i noticed something strange after i updated post-plugin-library , that the recent post widget works only on other pages ? it doesn’t work or even show up in home page ? you can check that on my blog .Thanks again

  • 4. Rob  |  June 4th, 2008 at 2:14 pm

    Mohamad: Did you use the automatic updater or did you do it ‘by hand’? I’m trying to find out if the plugin was reactivated or not.

    The problem is due to the new post status option not being set properly. I think it should be solved by going to the plugin’s general settings screen and making sure that published posts are set to be shown.

    As to why the status default doesn’t get set properly… that I’d like to find out!


  • 5. Moser  |  June 5th, 2008 at 4:48 am

    I had the same problem and it all started with updating all plugins automatically. It was fixed by going to random posts settings and setting “yes” to Display posts that are published. You can leave all the others to “no” depending on what you want to display.

  • 6. Mohamad  |  June 5th, 2008 at 7:52 pm

    Hey Rob thank you for your replay, yes indeed i used the automatic updater, but i fixed that problem by manual install (FTP plugin to root)?. Everything works great now thank you again.

  • 7. Rob  |  June 7th, 2008 at 9:29 am

    Moser: The default values should be set correctly if the plugin was re-activated on update but some people have experienced a problem. I usually make life easier by phrasing settings so that the default value corresponds also to an unset value but I didn’t give it enough thought this time.

  • 8. Rob  |  June 7th, 2008 at 9:30 am

    Mohamad: I’m very glad to hear it.

  • 9. Mikko  |  June 9th, 2008 at 3:26 pm


    I have a problem: I updated the library (to from the plugin panel. The plugin didn’t reactivate properly and now I can’t access the admin interface at all: I only get empty pages.

    I removed the update and installed it again – no help. I removed it and installed instead – no help. Any ideas?

  • 10. Mikko  |  June 9th, 2008 at 5:12 pm

    Whew, fixed! The problem was caused by Similar Posts requiring the ppl_plugin_basename function. I uncommented that line and everything worked. I then upgraded Similar Posts, and now everything’s fine.

  • 11. jethonda  |  July 31st, 2008 at 10:41 am

    can I use this plugin in blogspot?

  • 12. Rob  |  August 1st, 2008 at 2:22 pm

    jethonda: Sorry — just for WordPress.

  • 13. Craig  |  September 16th, 2008 at 8:58 pm

    Is there a source repository (SVN for example) available for this plugin (and your other plugins)?

  • 14. Rob  |  September 16th, 2008 at 9:13 pm

    Craig: Yes the plugins are hosted at and the svn is for example

    I don’t recommend using trunk but the tagged releases are the same ones available via the WordPress updater.

  • 15. Adam  |  October 7th, 2008 at 5:53 pm

    Hey Rob,

    I’m getting that weird error again after updating to the latest version:

    /mnt/local/home/username/ on line 624

    I apparently deleted your email that explained the one-line code solution so I thought I’d ask for it again here in case I lose more emails or anyone else has the same issue.

  • 16. Ron  |  October 16th, 2008 at 3:41 pm

    Hey Rob,

    We looking for a nice recent posts plug-in and came across yours seems like it would do the trick for me, but I can’t seem to get my WordPress installation to see your plug-in or the plug-in library. I’ve copied them over to the plug-in dir where all of the others are, and nothing. Has this happened before, or am i just not reading the correct information on installation.

    WordPress ver. 2.6.2
    Apache 2.2
    PHP 5
    Using a local box at the moment: Windows XP
    Not upgrading so Iā€™m working with:
    Library version:

  • 17. ra8org  |  October 25th, 2008 at 3:31 pm

    Cant download this plugin !!!

  • 18. Aida  |  October 31st, 2008 at 4:50 pm

    I download post-plugin-library and I active it. But I can’t see this in the option page and I can’t see the list in my page but I write on this page : or
    Why? Help me please.

  • 19. jehy  |  November 7th, 2008 at 6:12 pm

    Hello. Sorry, could you tell me, how to make simular posts widget to be displayed only on post page – not in search or categories…
    I am sure there is an option but I just couldn’t find and I don’t wanna hardcode…

  • 20. jehy  |  November 7th, 2008 at 6:17 pm

    Oh, sorry, found it.
    Stupid me.
    I use tablet instead of mouse and I couldn’t properly click the “change” link on widget.
    Sorry, your plugin is great. Get 5 rate šŸ™‚

  • 21. jesusguevarautomotriz  |  November 30th, 2008 at 7:44 am

    Any Thing?:

    Fatal error: require() [function.require]: Failed opening required ‘/home2/industu9/public_html/blog/wp-content/plugins/post-plugin-library/common_functions.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home2/industu9/public_html/blog/wp-content/plugins/wp-post-plugin-library/post-plugin-library.php on line 40

  • 22. Alex  |  December 12th, 2008 at 8:11 am

    Q: Supported WP 2.7?..

  • 23. Michael  |  December 26th, 2008 at 10:50 pm

    I just updated to 2.7 but the Post Plugin Library does not appear to work, so the “similar posts” functionality is also not functioning. Are there plans to update this plugin for wp 2.7?

  • 24. suresh  |  December 30th, 2008 at 8:26 am

    Plugins are excellent.Thanks for the plugin.I’m using it along with Post-Plugin Library. . However i’m struck with a custom tag thumbnail. I’ve added code in the output template but thumbnails shows up very large in the sidebar . how do i resize ? pls advice. thanks.
    <li><a href="{url}"><img src="{custom:thumbnail}"/>{link}</li>

  • 25. Freebies  |  January 18th, 2009 at 4:02 am

    I’ve used this on my other blogs but I just started a new one and it doesn’t seem to work – it seems I’m using the latest version of WP 2.7 and your plugin isn’t compatible. Any plans to update it? Thanks in advance…

  • 26. Dobo12  |  February 4th, 2009 at 7:52 am

    Please, I want to know is this plagin for WP 2.7 or not? Tahnks

  • 27. broono  |  May 22nd, 2009 at 10:31 am

    how i use it ?

  • 28. Kjetil  |  May 25th, 2009 at 10:00 pm

    Any news on plans to update the plugins beyond WP2.6.2?
    Would be too bad skipping the Recent & Random posts plugins since they perform very well. But after discovering a security hole in WP262 (have no idea how they got in) I’m getting eager to upgrade – at least to 265.
    Could you please inform us?

  • 29. oteller  |  July 2nd, 2009 at 4:43 pm

    You have very good site!
    In saecula saeculorum