Params in Custom Component List View

Question

I'm fairly new to Joomla and I'm developing my first component. I finished up the backend and I'm working on the frontend. I have most of the functionality figured out but I can't figure out how to get the Page heading to display from the Menu item params.

I looked all around but I can't get mine to display. I've looked at the Article component for guidance but it doesn't work.

I copied this directly from the Article component, but after debugging I noticed that params is null:

<?php if ($this->params->get('show_page_heading',1)) : ?>
    <h1><?php echo  $this->params->get('page_heading') ? $this->params->get('page_heading') : JFactory::getApplication()->getMenu()->getActive()->title; ?></h1>
<?php endif; ?>

So then I figured I must add some code to the view.html.php file. So I made some modifications to my display method to match what the Article component has. This time I get the following error message that points to when I'm trying to assign params to $this:

Fatal error: Call to a member function get() on null

I'm thinking maybe it's because I'm working on a list view and the Article code is for a single item view.

Any help would be appreciated.

Here's the code I have in my view.html.php file:

class LibraryViewItems extends JViewLegacy {

    protected $items;
    protected $params;
    protected $state;

    public function display($tpl = null) {          
        $this->items = $this->get('Items');
        $state      = $this->get('State');
        $this->params = $this->state->get('params');

        if (count($errors = $this->get('Errors'))) {
            JError::raiseError(500, implode("\n", $errors));
            return false;
        }

        parent::display($tpl);
    }


}

Answer 1

It looks like you are trying to get the menu parameters for your current active menu. Try the following code, this hasn't been tested, I am giving you this reference from memory.

$app = JFactory::getApplication();
$params = $app->getMenu()->getActive()->getParams();

That may work for the current active menu parameters. If not you may have to pass the current Itemid into get params to get that array. In that instance try the following:

$app = JFactory::getApplication();
$Itemid = $app->getMenu()->getActive()->id;
$params = $menu->getParams($Itemid);

Maybe one of those 2 solutions will work for you. If you put this in your view.html.php file you can assign the variables to $this so that is passes into your template file for the component. ($this->Itemid, etc etc)

Answer 2

You are getting $params from $state

 $state = $this->get('State');

This means the state must have $params populated in your model. Check if you are populating the $state with $params in your model's populateState function

protected function populateState($ordering = null, $direction = null) {
    $params = JComponentHelper::getParams('com_mycomponent');
    $this->setState('params', $params);

    parent::populateState($ordering, $direction);
}

Answer 3

Addendum:

OP wants the menu item params accessible in the view, but he tries to override the component params var ($this->params) with the menu item params object/class. Which is unnecessary complicated. In the core article component, the component and the menu item params are merged (in the view.html.php), which is cool if you are trying to override some stuff. The correct answer to his question is to use $params = JFactory::getApplication()->getMenu()->getActive()->getParams(); in the default.php of the view. Which allows: $params->get('page_heading'); (IF that view gets called via a menu item.)

Get menu item params:

    $app = JFactory::getApplication();
    $menu = $app->getMenu()->getActive();
    $params = $menu->getParams();

Get component params:

$this->params = $this->state->get('params');

Merge them in the view.html.php -> display function (taken from the view.html.php of the article view):

    $this->params = $this->state->get('params');
    $active       = $app->getMenu()->getActive();
    $temp         = clone $this->params;

if ($active)
        {
            $currentLink = $active->link;

            // If the current view is the active item and an article view for this article, then the menu item params take priority
            if (strpos($currentLink, 'view=article') && strpos($currentLink, '&id=' . (string) $item->id))
            {
                // Load layout from active query (in case it is an alternative menu item)
                if (isset($active->query['layout']))
                {
                    $this->setLayout($active->query['layout']);
                }
                // Check for alternative layout of article
                elseif ($layout = $item->params->get('article_layout'))
                {
                    $this->setLayout($layout);
                }

                // $item->params are the article params, $temp are the menu item params
                // Merge so that the menu item params take priority
                $item->params->merge($temp);
            }
            else
            {
                // Current view is not a single article, so the article params take priority here
                // Merge the menu item params with the article params so that the article params take priority
                $temp->merge($item->params);
                $item->params = $temp;

                // Check for alternative layouts (since we are not in a single-article menu item)
                // Single-article menu item layout takes priority over alt layout for an article
                if ($layout = $item->params->get('article_layout'))
                {
                    $this->setLayout($layout);
                }
            }
        }
        else
        {
            // Merge so that article params take priority
            $temp->merge($item->params);
            $item->params = $temp;

            // Check for alternative layouts (since we are not in a single-article menu item)
            // Single-article menu item layout takes priority over alt layout for an article
            if ($layout = $item->params->get('article_layout'))
            {
                $this->setLayout($layout);
            }
        }