extension override in joomla 4

[rashgang]

Is there any option given in joomla 4 for override the any component or module file.

[ceford]

You can often override component or module layouts to customise appearance. Look in the layouts folder for examples. And in template html and css folders.

[SharkyKZ]

Extensions that use services can have their services overridden using onBeforeExtensionBoot/onAfterExtensionBoot events. This is supported by components, modules and plugins. However, core modules and plugins haven't been converted to support this. Another option is to use some autoloader hacks but it's not recommended.

[rashgang]

@SharkyKZ could you show me some examples it might helpful for me to override any extension

[Webdongle]

You can use the Template manager to override Components, Modules and Plugins in J4 just like J3

[rashgang]

I woud like to override extension model or controller file. How to do it.

[pe7er]

I woud like to override extension model or controller file. How to do it.

Joomla does not have overrides for extension Models or Controllers.
However, Joomla will load Model- and Controller classes only once and you can use that behavior:
You can create a system plugin that loads your own class "override" before Joomla loads the original class.

Copy the Model or Controller that you want to override to your plugin,
make your changes in that copy
and let your plugin load that file before Joomla does.

Make sure that you only load your own "override" when needed.
So when the site/admin + option + view + etc are not where you need to run your plugin, "return false" to exit the plugin.

[SharkyKZ]

@SharkyKZ could you show me some examples it might helpful for me to override any extension

Basic code for the plugin:

Code: Select all

public function onAfterExtensionBoot(\Joomla\Event\EventInterface $event)
{
	// Test that this is a component.
	if ($event->getArgument('type') !== 'Joomla\\CMS\\Extension\\ComponentInterface')
	{
		return;
	}

	// Test that this is com_content component.
	if ($event->getArgument('extensionName') !== 'content')
	{
		return;
	}

	// Get the container.
	$container = $event->getArgument('container');

	if (!($container instanceof \Joomla\DI\Container))
	{
		return;
	}

	// Service key to override.
	$class = 'Joomla\\CMS\\MVC\\Factory\\MVCFactoryInterface';

	// Service key not used or can't be overridden.
	if (!$container->has($class) || $container->isProtected($class))
	{
		return;
	}

	// Register the custom MVC factory.
	$container->set($class, new MyMVCFactory);
}

Inside the MyMVCFactory you would add logic to load your class for a given model/controller/view name. It's best that you inspect Joomla\CMS\MVC\Factory\MVCFactory class to see how standard MVC factory works.

Unlike with J3 method mentioned by Peter, your class names don't have to and should not match the overridden class names. And you don't have to copy entire class into your own class. Instead you can extend the class and override only specific methods or class properties.

[pe7er]

Unlike with J3 method mentioned by Peter, your class names don't have to and should not match the overridden class names. And you don't have to copy entire class into your own class. Instead you can extend the class and override only specific methods or class properties.

Thanks for that information SharkyKZ!
I'm developing a new J4 component + plugin, and this is very useful info!

[biirc]

Hi,

I have the same question i need to override the Content Router (components/com_content/src/Service/Router.php) in my plugin. (post edited to use the eventInterface syntax

Code: Select all

    public function onAfterExtensionBoot(\Joomla\Event\EventInterface $event)
    {
        // Test that this is a component.
        if ($event->getArgument('type') !== 'Joomla\\CMS\\Extension\\ComponentInterface') {
            return;
        }

        // Test that this is com_content component.
        if ($event->getArgument('extensionName') !== 'content') {
            return;
        }

        // Get the container.
        $container = $event->getArgument('container');

        if (!($container instanceof \Joomla\DI\Container))
        {
            return;
        }

        $app = Factory::getApplication();
        $db = Factory::getDbo();
        $router_file_path  = JPATH_PLUGINS . '/system/myplugin/routers/com_' . $extensionName . '/router.php';
        if (file_exists($router_file_path)){
            // Service key to override.
            $class = 'Joomla\\CMS\\Component\\Router\\RouterFactoryInterface';
            $category_class = 'Joomla\\CMS\\Categories\\CategoryFactoryInterface';
            if (!$container->has($class) || $container->isProtected($class))
            {
                return;
            }
            if (!$container->has($category_class) || $container->isProtected($category_class))
            {
                return;
            }
            // Register the custom Router.
            require_once $router_file_path;
            $prev_router = $container->get($class);
            $container->set($class, new Joomla\Component\MyPlugin\Content\Site\Service\MyPluginContentRouter(
                $app,
                $app->getMenu(),
                $container->get($category_class),
                $db
            ));
        }

Best regards,
Stéphane