You are viewing the PKP Support Forum | PKP Home Wiki

Creating new plugin - 404 Error

OJS development discussion, enhancement requests, third-party patches and plug-ins.

Moderators: jmacgreg, btbell, michael, bdgregg, barbarah, asmecher

Forum rules
The Public Knowledge Project Support Forum is moving to http://forum.pkp.sfu.ca

This forum will be maintained permanently as an archived historical resource, but all new questions should be added to the new forum. Questions will no longer be monitored on this old forum after March 30, 2015.

Creating new plugin - 404 Error

Postby rania » Thu Sep 15, 2011 6:51 am

Hello all!

Based on requests from our latest journal installation, we changed the OJS code to implement the 'Browse By' a setting name (e.g types, disciplines etc.). Currently I am working to develop this functionality as a plugin in order to contribute it to the community, but I have some problems (maybe I should mention that this is my first OJS plugin :roll: ), so any help will be deedply appreciated!

First of all I should mention that I work with OJS 2.3.5 and I install the plugin manually: I created a folder in plugins/generic/browse and put all the code there. Also, I manually added the browsePlugin in versions Table and the plugin is enabled.
So, the register function in BrowsePlugin.inc.php is the following:
Code: Select all
function register($category, $path) {
      if (parent::register($category, $path)) {      
         if ($this->getEnabled()) {
            $BrowseDAO = &new BrowseDAO();
            $returner = &DAORegistry::registerDAO('BrowseDAO', $BrowseDAO);
            // Handler for public thesis abstract pages
            HookRegistry::register('LoadHandler', array($this, 'handleRequest'));   
         return true;
      return false;

Then, the handler is loaded:
Code: Select all
function handleRequest($hookName, $args) {
      $page =& $args[0];
      $op =& $args[1];
      $sourceFile =& $args[2];

      // If the request is for the log analyzer itself, handle it.
      if ($page === 'browse') {
         Registry::set('plugin', $this);
         define('HANDLER_CLASS', 'BrowseHandler');
         return true;

      return false;

In BrowseHandler.inc.php, I have specified index(), which loads a simple test.tpl (this template justs prints a test paragraph):
Code: Select all
function index()
      $templateManager =& TemplateManager::getManager();

So, the URL: http://www.myJournalUrl.../index.php/{journal_initials}/browse should show the test paragraph, but instead it displays 404 error :oops: :shock:
Code: Select all
Stack Trace:

File: C:\xampp\htdocs\ojs_2.3.5_onlinereader\lib\pkp\classes\core\PKPPageRouter.inc.php line 230
Function: Dispatcher->handle404()

File: C:\xampp\htdocs\ojs_2.3.5_onlinereader\lib\pkp\classes\core\Dispatcher.inc.php line 129
Function: PKPPageRouter->route(Object(Request))

File: C:\xampp\htdocs\ojs_2.3.5_onlinereader\lib\pkp\classes\core\PKPApplication.inc.php line 180
Function: Dispatcher->dispatch(Object(Request))

File: C:\xampp\htdocs\ojs_2.3.5_onlinereader\index.php line 65
Function: PKPApplication->execute()

What am I doing wrong? I have tried various ways to do this, based on other generic plugins and still the same problem! :(

Also, how can I specify to load different functions based on the URL? (e.g. if the URL is browse/types, it should load the function types() from BrowseHandler.inc.php)

Can someone please help me with this.

Thank you in advance,

Posts: 35
Joined: Thu Nov 08, 2007 1:37 am

Re: Creating new plugin - 404 Error

Postby jmacgreg » Sun Sep 18, 2011 9:03 pm

Hi Rania,

It looks like you may have tried getting this working by using the COUNTER plugin as a template (which is exactly how I would've gone about doing so, as well). It looks like you've stripped out a few possibly necessary lines from the index() function in your BrowseHandler.inc.php file, particularly the following:

Code: Select all
$plugin =& $this->plugin;

Try adding those lines, and let us know if you have any better luck. I'll ask a more senior developer if he can get back to you about your other question.

Posts: 4191
Joined: Tue Feb 14, 2006 10:50 am

Re: Creating new plugin - 404 Error

Postby asmecher » Sun Sep 18, 2011 11:39 pm

Hi Rania,

The most likely (and frustrating) problem is that the version entry in the database is not complete. You can tell this because the register() function will never get called -- try throwing a few "echo" statements in there to see whether that's the case. You can get the version entry to be created automatically by running the upgrade script (php tools/upgrade.php upgrade). (I'm assuming this is a development install? Otherwise be sure that your installation is in a good state before you run that.)

Alec Smecher
Public Knowledge Project Team
Posts: 10015
Joined: Wed Aug 10, 2005 12:56 pm

Re: Creating new plugin - 404 Error

Postby rania » Fri Sep 23, 2011 8:24 am

Hello Alec and James!

Thank you very much for the replies! :D

For anyone else who may experience the same problem, it had to do with the registration in the database. Running the upgrade script (php tools/upgrade.php upgrade), as Alec pointed out, fixed the problem. :) The logs indeed showed that the register() function was called only when I got the plugin enabled (from the administrator interface) and only then.

I am happy to report that the plugin is almost ready, just finishing some testing... So, I will be contributing it, sortly! :D

Again many many thanks!


Posts: 35
Joined: Thu Nov 08, 2007 1:37 am

Return to OJS Development

Who is online

Users browsing this forum: No registered users and 5 guests