EZP-22324: Implemented premium subscriber content

A custom location view provider displays a teasing template
if the content is Premium (section id 7 (Premium)), and if the
user doesn't have the subscriber role (id: 6)

section_id and role_id are configured in default_settings.yml.

PremiumContent/PremiumLocationViewProvider.php

@@ -0,0 +1,61 @@
+<?php
+/**
+ * This file is part of the eZ Publish Kernel package
+ *
+ * @copyright Copyright (C) eZ Systems AS. All rights reserved.
+ * @license For full copyright and license information view LICENSE file distributd with this source code.
+ */
+namespace EzSystems\DemoBundle\PremiumContent;
+
+use eZ\Publish\API\Repository\Repository;
+use eZ\Publish\API\Repository\Values\Content\Location;
+use eZ\Publish\API\Repository\Values\User\Role;
+use eZ\Publish\Core\MVC\Symfony\View\ContentView;
+use eZ\Publish\Core\MVC\Symfony\View\Provider\Location as LocationViewProvider;
+
+/**
+ * Returns the premium_content view if it applies to a location and if the user isn't a Premium subscriber.
+ */
+class PremiumLocationViewProvider implements LocationViewProvider
+{
+    /**
+     * ID of the section used to mark content as Premium
+     * @var int
+     */
+    private $premiumSectionId;
+
+    /** @var PremiumSubscriptionChecker */
+    private $subscriptionChecker;
+
+    /**
+     * @var Repository
+     */
+    private $repository;
+
+    public function __construct( Repository $repository, PremiumSubscriptionChecker $subscriptionChecker, $premiumSectionId )
+    {
+        $this->repository = $repository;
+        $this->premiumSectionId = $premiumSectionId;
+        $this->subscriptionChecker = $subscriptionChecker;
+    }
+
+    public function getView( Location $location, $viewType )
+    {
+        if ( $viewType !== 'full' )
+        {
+            return null;
+        }
+
+        if ( $location->getContentInfo()->sectionId !== $this->premiumSectionId )
+        {
+            return null;
+        }
+
+        if ( $this->subscriptionChecker->userIsSubscriber( $this->repository->getCurrentUser() ) )
+        {
+            return null;
+        }
+
+        return new ContentView( "eZDemoBundle:$viewType:premium_content.html.twig" );
+    }
+}

PremiumContent/PremiumSubscriptionChecker.php

@@ -0,0 +1,57 @@
+<?php
+/**
+ * This file is part of the eZ Publish Kernel package
+ *
+ * @copyright Copyright (C) eZ Systems AS. All rights reserved.
+ * @license For full copyright and license information view LICENSE file distributd with this source code.
+ */
+namespace EzSystems\DemoBundle\PremiumContent;
+
+use eZ\Publish\API\Repository\Values\User\User;
+use eZ\Publish\API\Repository\Repository;
+use eZ\Publish\API\Repository\Values\User\Role;
+
+class PremiumSubscriptionChecker
+{
+    /**
+     * ID of the premium subscriber role
+     */
+    private $roleId = 6;
+
+    /**
+     * @var Repository|\eZ\Publish\Core\Repository\Repository
+     */
+    private $repository;
+
+    public function __construct( Repository $repository, $subscriberRoleId )
+    {
+        $this->repository = $repository;
+        $this->roleId = $subscriberRoleId;
+    }
+
+    public function userIsSubscriber( User $user )
+    {
+        $roleService = $this->repository->getRoleService();
+        return $this->repository->sudo(
+            function ( Repository $repository ) use ( $user, $roleService )
+            {
+                foreach ( $repository->getUserService()->loadUserGroupsOfUser( $user ) as $group )
+                {
+                    foreach ( $roleService->getRoleAssignmentsForUserGroup( $group ) as $role )
+                    {
+                        if ( $this->isSubscriberRole( $role->role ) )
+                        {
+                            return true;
+                        }
+                    }
+                }
+                return false;
+            }
+        );
+    }
+
+    public function isSubscriberRole( Role $role )
+    {
+        return $role->id === $this->roleId;
+    }
+}

Resources/config/default_settings.yml

@@ -34,3 +34,7 @@ parameters:
     ## Search Page
     # Number of results displayed per page in the simple search
     ezdemo.search.list.limit: 10
+
+    ## Premium content
+    ezdemo.premium_content.section_id: 7
+    ezdemo.premium_content.role_id: 6

Resources/config/services.yml

@@ -69,3 +69,18 @@ services:
         scope: request # needed as we have the request as a dependency here
         tags:
             - { name: knp_menu.menu, alias: top } # The alias is what is used to retrieve the menu
+
+    ezdemo.premium_content.location_view_provider:
+        class: EzSystems\DemoBundle\PremiumContent\PremiumLocationViewProvider
+        arguments:
+            - @ezpublish.api.repository
+            - @ezdemo.premium_content.subscription_checker
+            - %ezdemo.premium_content.section_id%
+        tags:
+            - {name: ezpublish.location_view_provider, priority: 30}
+
+    ezdemo.premium_content.subscription_checker:
+        class: EzSystems\DemoBundle\PremiumContent\PremiumSubscriptionChecker
+        arguments:
+            - @ezpublish.api.repository
+            - %ezdemo.premium_content.role_id%

Resources/views/full/premium_content.html.twig

@@ -0,0 +1,21 @@
+{% extends "eZDemoBundle::pagelayout.html.twig" %}
+
+{% block content %}
+<section class="content-view-full">
+    <article class="class-article row">
+        <div class="span8">
+            <div class="attribute-header">
+                <h1>{{ ez_render_field( content, 'title' ) }}</h1>
+            </div>
+
+            {% if not ez_is_field_empty( content, 'subscriber_teaser' ) %}
+                <div class="attribute-short">
+                    {{ ez_render_field( content, 'subscriber_teaser' ) }}
+                </div>
+            {% endif %}
+
+            This article is only available to Premium subscribers.
+        </div>
+    </article>
+</section>
+{% endblock %}

doc/specifications/premium_content.md

@@ -0,0 +1,11 @@
+# Premium content
+
+This feature displays content marked as Premium using a special teaser and informations about the status. It is
+an example of what could be used to offer a paywall.
+
+## Implementation
+Premium content is identified belonging to section Premium (ID: 7). Subscribers have the Subscriber role (ID: 6).
+
+A standard policy check can't be used here, as it would prevent the content from  being returned in searches and lists.
+Instead, Anonymous user can read this content, but a custom ViewProvider is used to return a special premium_teaser
+template when a premium content is viewed by a non-subscriber.