I started working on new WIdget API see new Widget base class https://github.com/piwik/piwik/compare/7861#diff-2627bb10f1c9060b562ef684be844e8dR1 and an example widget https://github.com/piwik/piwik/compare/7861#diff-328e5dc766c1f330bc3efc090ee7d32fR21

Fow now it is straight forward and very similar to the Report class.

There are currently some "problems":

• configureWidgetList(WidgetList $widgetlist) does not really belong there (does two things, creates a new widget, and configures other widgets). Example: https://github.com/piwik/piwik/blob/0ae422cf0389e6a0c1a663340ebcaee77d177852/plugins/Goals/Widgets/WidgetConfig.php#L15 (ignore the isEnabled) The configureWidgetList is meant to add multiple widgets for one class (eg for each goal) and / or to remove widgets from the list. We have 2 more alternatives, none of them is really great:
  • Static configureWidgetsList method (would be much better I think)
  • Use an event Piwik::postEvent('WidgetsList.addWidgets/filterWidgets', array($widgetsList))
  • Let plugin developers define a class WidgetsList or so in their plugin which will allow them to configure it.
  • I'm sure there are more possible solution
• If widgets require dependencies we will have to create all of them which can slow down page creation. It's similar to commands just that for commands performance is not such a big deal etc. Also of course other problems come with having to create dependencies similar to commands. We could use a similar concept as suggested in Dependency injection in commands #7175 for example. Just that we will need dependencies in that static config method for example for such cases https://github.com/piwik/piwik/compare/7861#diff-13dfb9f63e96dfcbc0c5b90973b0a55bR19 . Having such a config might be beneficial for Report classes as well and especially when working on Add possibility to manage and view Apps #7131 and Build a generic Analytics platform: allow to measure 'Mobile App', 'Intranet Website', 'Wearable', 'Sensor' and more #4734 where a eg a type "MobileApp" can change the name of a report/widget and enable/disable it.
• Having a WidgetConfiguration class (see previous item re dependencies) could also help to create a widget for a report like this https://github.com/piwik/piwik/compare/7861?expand=1#diff-04ac2e4c6abd747be0f7894ca9bede54R25
• We have similar logic for Reports, and in the future maybe more such things (eg ReportByDimensionView). Eg both have a render method meaning they could implement something like Renderable and they have methods like getAction, getMethod, checkEnabled which could implement something like Routable. As Piwik 3.0 is coming closer we have the chance to change a few things but I don't like to use interfaces here as it will be problematic to keep BC.

If any ideas or more feedback @mattab @diosmosis @mnapoli please comment. As more problems come up I will comment as well.

Maybe something like this:

class GetVisitorProfilePopup extends \Piwik\Plugin\Widget
{
    public static function configure(WidgetConfig $config)
    {
        $config->setCategory('Live!');
        $config->setName('Live_VisitorProfile');
        $config->setOrder(25);
        $config->disable();
    }

    public function render()
    {
    }

    public static function configureWidgetsList(WidgetsList $widgetsList)
    {
        // only needed in rare cases when removing a widget or so
    }

}

WidgetConfig can be also used in a WidgetsList.addWidgets event (although this is currently deprecated)

$config = new WidgetConfig();
$config->setCategory('Live!');
$config->setName(Piwik::translate('UserCountryMap_RealTimeMap'));
$config->setModule('UserCountryMap');
$config->setAction('realtimeMap');
$config->setOrder(5);
WidgetsList::getInstance()->addWidget($config);

// instead of 
WidgetsList::add('Live!', Piwik::translate('UserCountryMap_RealTimeMap'), 'UserCountryMap', 'realtimeMap', array(), $order = 5);

And it will be probably used in reports to create a widget from a report eg

    protected function init()
    {
        parent::init();
        $this->order = 2;

        $this->createWidget()
             ->setName('Live_VisitorLog')
             ->setOrder(10)
             ->setParameters(array('small' => 1));
    }

fixed via #8442