Joomla 2.5 component controller loading

Question

I've been trying to learn how to build a Joomla component.

I've been using http://joomlaprogrammingbook.com/ book which is great. I can now do plugins and modules without too much of a problem. However I'm getting stuck with how certain controllers get loaded for components. The site given has the full code if it's needed.

The initial controller loaded is:

 class JoomproSubsController extends JController
{
    /**
    * @var      string  The default view.
    * @since    1.6
    */
protected $default_view = 'submanager';

/**
 * Method to display a view.
 *
 * @param   boolean         $cachable   If true, the view output will be cached
 * @param   array           $urlparams  An array of safe url parameters and their variable types, for valid values see {@link JFilterInput::clean()}.
 *
 * @return  JController     This object to support chaining.
 */ 
public function display($cachable = false, $urlparams = false)
{
    JLoader::register('JoomproSubsHelper', JPATH_COMPONENT.'/helpers/joomprosubs.php');

    // Load the submenu.
    JoomproSubsHelper::addSubmenu(JRequest::getCmd('view', 'submanager'));

    $view = JRequest::getCmd('view', 'submanager');
    $layout = JRequest::getCmd('layout', 'default');
    $id = JRequest::getInt('id');

    // Check for edit form.
    if ($view == 'subscription' && $layout == 'edit' && !$this->checkEditId('com_joomprosubs.edit.subscription', $id)) {
        // Somehow the person just went to the form - we don't allow that.
        $this->setError(JText::sprintf('JLIB_APPLICATION_ERROR_UNHELD_ID', $id));
        $this->setMessage($this->getError(), 'error');
        $this->setRedirect(JRoute::_('index.php?option=com_joomprosubs&view=submanager', false));

        return false;
    }

    parent::display();

    return $this;
}

}

I can see how and when this is loaded. However at some point in this it also seems to load class JoomproSubsControllerSubManager extends JControllerAdmin

now I though that to do this it would need a url which included com_joomproSubs?task=submanager

but that doesn't exist. So my question is how can this happen?

Unknown Unknown · Accepted Answer · 2013-04-23T00:05:49

In Joomla! everything passes through index.php (although in the front-end you won't see index.php in the URL if the SEF options are turned on).

Without SEF etc

So the entry points are index.php or /administrator/index.php (for the backend). To this are appended some parameters that tell Joomla! how to route the request.

option=X
task=Y.Z
view=V

`option`

This is the parameter that tells Joomla what component is to handle the request. e.g. option=com_content for the component that handles standard articles. Subsequent to the component value being determined, Joomla is then expecting everything to be in the matching directory. In our example this will be /components/com_content/ or for the backend /administrator/components/com_content/

`task`

The task parameter can take a dot notation value of the form controller.method e.g. task=article.edit in the Article Manager. Using the elements of this value Joomla! loads the article.php file in the /com_content/controllers/ directory and fires the method edit

`view`

The view parameter is used to nominate a specific view within the same controller e.g. again in the com_content component you see these two variations in the value of view:

/administrator/index.php?option=com_content&view=featured

/administrator/index.php?option=com_content&view=articles

Joomla 2.5 component controller loading

2 Answers

Without SEF etc

option

task

view

`option`

`task`

`view`