How to create a document template from the plugin in Shopware 5?

I am trying to create a document through my plugin, the document is inside MyPlugin/Resources/views/documents/index_foo.tpl and i have registered the template by subscribing to event Enlight_Controller_Action_PostDispatchSecure

Also added the template directory $this->template->addTemplateDir($this->pluginDir . '/Resources/views/'); and its entry in the table s_core_documents but when i try to preview it by going to Basic Settings > PDF Document Creation > Preview

i get this error

Ups! Ein Fehler ist aufgetreten! Wir wurden bereits über das Problem > informiert und arbeiten an einer Lösung, bitte versuchen Sie es in > Kürze erneut.

But when i place the template inside themes/Bare/documents it works.

Any idea how can i achieve this with my own plugin?

Solution

After asking it in the Shopware community Shyim said that the event subscribed is too late for this, Instead use the event mentioned here

https://developers.shopware.com/developers-guide/event-list/#theme_inheritance_template_directories_collected

After using the event our Subscriber/TemplateRegistration.php looked like this

class TemplateRegistration implements SubscriberInterface
{
    /**
     * @var Enlight_Template_Manager
     */
    private $template;
    private $pluginDir;
    /**
     * TemplateRegistration constructor.
     * @param Enlight_Template_Manager $template
     * @param $pluginDir
     */
    public function __construct(Enlight_Template_Manager $template, $pluginDir)
    {
        $this->template = $template;
        $this->pluginDir = $pluginDir;
    }
    /**
     * @inheritDoc
     */
    public static function getSubscribedEvents()
    {
        return [
            'Theme_Inheritance_Template_Directories_Collected' => 'onCollectTemplateDirectories',
        ];
    }
    /**
     * @param \Enlight_Event_EventArgs $args
     */
    public function onCollectTemplateDirectories(\Enlight_Event_EventArgs $args)
    {
        $this->template->addTemplateDir($this->pluginDir . '/Resources/views/');
    }
}

But even doing so i still faced the error stating

Ups! Ein Fehler ist aufgetreten!
Die nachfolgenden Hinweise sollten Ihnen weiterhelfen.

Unable to load template snippet 'documents/index_foo.tpl' in engine/Library/Smarty/sysplugins/smarty_internal_templatebase.php on line 127
Stack trace:
#0 engine/Shopware/Components/Document.php(273): Smarty_Internal_TemplateBase->fetch('documents/index...', NULL)
#1 engine/Shopware/Controllers/Backend/Document.php(68): Shopware_Components_Document->render()
#2 engine/Library/Enlight/Controller/Action.php(182): Shopware_Controllers_Backend_Document->indexAction()
#3 engine/Library/Enlight/Controller/Dispatcher/Default.php(478): Enlight_Controller_Action->dispatch('indexAction')
#4 engine/Library/Enlight/Controller/Front.php(228): Enlight_Controller_Dispatcher_Default->dispatch(Object(Enlight_Controller_Request_RequestHttp), Object(Enlight_Controller_Response_ResponseHttp))
#5 engine/Shopware/Kernel.php(191): Enlight_Controller_Front->dispatch()
#6 vendor/symfony/http-kernel/HttpCache/SubRequestHandler.php(85): Shopware\Kernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#7 vendor/symfony/http-kernel/HttpCache/HttpCache.php(477): Symfony\Component\HttpKernel\HttpCache\SubRequestHandler::handle(Object(Shopware\Kernel), Object(Symfony\Component\HttpFoundation\Request), 1, true)
#8 engine/Shopware/Components/HttpCache/AppCache.php(261): Symfony\Component\HttpKernel\HttpCache\HttpCache->forward(Object(Symfony\Component\HttpFoundation\Request), true, NULL)
#9 vendor/symfony/http-kernel/HttpCache/HttpCache.php(267): Shopware\Components\HttpCache\AppCache->forward(Object(Symfony\Component\HttpFoundation\Request), true)
#10 engine/Shopware/Components/HttpCache/AppCache.php(102): Symfony\Component\HttpKernel\HttpCache\HttpCache->pass(Object(Symfony\Component\HttpFoundation\Request), true)
#11 shopware.php(122): Shopware\Components\HttpCache\AppCache->handle(Object(Symfony\Component\HttpFoundation\Request))
#12 {main}

The error above got resolved after i adjusted the return of the event in the method onCollectTemplateDirectories() in my Subscriber/TemplateRegistration.php

Now it looks like this after adjusting

class TemplateRegistration implements SubscriberInterface
{
    /**
     * @var Enlight_Template_Manager
     */
    private $template;
    private $pluginDir;

    /**
     * TemplateRegistration constructor.
     * @param Enlight_Template_Manager $template
     * @param $pluginDir
     */
    public function __construct(Enlight_Template_Manager $template, $pluginDir)
    {
        $this->template = $template;
        $this->pluginDir = $pluginDir;
    }

    /**
     * @inheritDoc
     */
    public static function getSubscribedEvents()
    {
        return [
            'Theme_Inheritance_Template_Directories_Collected' => 'onCollectTemplateDirectories',
        ];
    }

    /**
     * @param \Enlight_Event_EventArgs $args
     */
    public function onCollectTemplateDirectories(\Enlight_Event_EventArgs $args)
    {
        // commented the line below
        // $this->template->addTemplateDir($this->pluginDir . '/Resources/views/');

        // and used this one instead
        $dirs = $args->getReturn();
        $dirs[] = $this->pluginDir . '/Resources/views';
        $args->setReturn($dirs);
    }
}

The technical reason behind this was explained by Telgi in the community that

you have to use the one or the other depending on the event you are subscribing to. you need the adjust the return of the event. if you subscribe to another event, you need the template service

And now finally when i press the preview button of the template Basic Settings > PDF Document Creation > Preview i see the content/text whatever written in the template and no more errors.

Hope this helps someone in the future.