X-Git-Url: http://source.bookstackapp.com/bookstack/blobdiff_plain/7b6c88f17c595f3b0d88fe383827794b83dba3e7..refs/pull/261/head:/app/Services/PermissionService.php

diff --git a/app/Services/PermissionService.php b/app/Services/PermissionService.php
index 0fffe60f2..89f80f936 100644
--- a/app/Services/PermissionService.php
+++ b/app/Services/PermissionService.php
@@ -3,49 +3,117 @@
 use BookStack\Book;
 use BookStack\Chapter;
 use BookStack\Entity;
+use BookStack\EntityPermission;
 use BookStack\JointPermission;
 use BookStack\Ownable;
 use BookStack\Page;
 use BookStack\Role;
 use BookStack\User;
-use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Database\Connection;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Query\Builder as QueryBuilder;
+use Illuminate\Support\Collection;
 
 class PermissionService
 {
 
-    protected $userRoles;
-    protected $isAdmin;
     protected $currentAction;
-    protected $currentUser;
+    protected $isAdminUser;
+    protected $userRoles = false;
+    protected $currentUserModel = false;
 
     public $book;
     public $chapter;
     public $page;
 
+    protected $db;
+
     protected $jointPermission;
     protected $role;
+    protected $entityPermission;
+
+    protected $entityCache;
 
     /**
      * PermissionService constructor.
      * @param JointPermission $jointPermission
+     * @param EntityPermission $entityPermission
+     * @param Connection $db
      * @param Book $book
      * @param Chapter $chapter
      * @param Page $page
      * @param Role $role
      */
-    public function __construct(JointPermission $jointPermission, Book $book, Chapter $chapter, Page $page, Role $role)
+    public function __construct(JointPermission $jointPermission, EntityPermission $entityPermission, Connection $db, Book $book, Chapter $chapter, Page $page, Role $role)
     {
-        $this->currentUser = auth()->user();
-        $userSet = $this->currentUser !== null;
-        $this->userRoles = false;
-        $this->isAdmin = $userSet ? $this->currentUser->hasRole('admin') : false;
-        if (!$userSet) $this->currentUser = new User();
-
+        $this->db = $db;
         $this->jointPermission = $jointPermission;
+        $this->entityPermission = $entityPermission;
         $this->role = $role;
         $this->book = $book;
         $this->chapter = $chapter;
         $this->page = $page;
+        // TODO - Update so admin still goes through filters
+    }
+
+    /**
+     * Set the database connection
+     * @param Connection $connection
+     */
+    public function setConnection(Connection $connection)
+    {
+        $this->db = $connection;
+    }
+
+    /**
+     * Prepare the local entity cache and ensure it's empty
+     */
+    protected function readyEntityCache()
+    {
+        $this->entityCache = [
+            'books' => collect(),
+            'chapters' => collect()
+        ];
+    }
+
+    /**
+     * Get a book via ID, Checks local cache
+     * @param $bookId
+     * @return Book
+     */
+    protected function getBook($bookId)
+    {
+        if (isset($this->entityCache['books']) && $this->entityCache['books']->has($bookId)) {
+            return $this->entityCache['books']->get($bookId);
+        }
+
+        $book = $this->book->find($bookId);
+        if ($book === null) $book = false;
+        if (isset($this->entityCache['books'])) {
+            $this->entityCache['books']->put($bookId, $book);
+        }
+
+        return $book;
+    }
+
+    /**
+     * Get a chapter via ID, Checks local cache
+     * @param $chapterId
+     * @return Book
+     */
+    protected function getChapter($chapterId)
+    {
+        if (isset($this->entityCache['chapters']) && $this->entityCache['chapters']->has($chapterId)) {
+            return $this->entityCache['chapters']->get($chapterId);
+        }
+
+        $chapter = $this->chapter->find($chapterId);
+        if ($chapter === null) $chapter = false;
+        if (isset($this->entityCache['chapters'])) {
+            $this->entityCache['chapters']->put($chapterId, $chapter);
+        }
+
+        return $chapter;
     }
 
     /**
@@ -64,7 +132,7 @@ class PermissionService
         }
 
 
-        foreach ($this->currentUser->roles as $role) {
+        foreach ($this->currentUser()->roles as $role) {
             $roles[] = $role->id;
         }
         return $roles;
@@ -76,43 +144,85 @@ class PermissionService
     public function buildJointPermissions()
     {
         $this->jointPermission->truncate();
+        $this->readyEntityCache();
 
         // Get all roles (Should be the most limited dimension)
-        $roles = $this->role->with('permissions')->get();
+        $roles = $this->role->with('permissions')->get()->all();
 
         // Chunk through all books
-        $this->book->with('permissions')->chunk(500, function ($books) use ($roles) {
-            $this->createManyJointPermissions($books, $roles);
+        $this->bookFetchQuery()->chunk(5, function ($books) use ($roles) {
+            $this->buildJointPermissionsForBooks($books, $roles);
         });
+    }
 
-        // Chunk through all chapters
-        $this->chapter->with('book', 'permissions')->chunk(500, function ($chapters) use ($roles) {
-            $this->createManyJointPermissions($chapters, $roles);
-        });
+    /**
+     * Get a query for fetching a book with it's children.
+     * @return QueryBuilder
+     */
+    protected function bookFetchQuery()
+    {
+        return $this->book->newQuery()->select(['id', 'restricted', 'created_by'])->with(['chapters' => function($query) {
+            $query->select(['id', 'restricted', 'created_by', 'book_id']);
+        }, 'pages'  => function($query) {
+            $query->select(['id', 'restricted', 'created_by', 'book_id', 'chapter_id']);
+        }]);
+    }
 
-        // Chunk through all pages
-        $this->page->with('book', 'chapter', 'permissions')->chunk(500, function ($pages) use ($roles) {
-            $this->createManyJointPermissions($pages, $roles);
-        });
+    /**
+     * Build joint permissions for an array of books
+     * @param Collection $books
+     * @param array $roles
+     * @param bool $deleteOld
+     */
+    protected function buildJointPermissionsForBooks($books, $roles, $deleteOld = false) {
+        $entities = clone $books;
+
+        /** @var Book $book */
+        foreach ($books->all() as $book) {
+            foreach ($book->getRelation('chapters') as $chapter) {
+                $entities->push($chapter);
+            }
+            foreach ($book->getRelation('pages') as $page) {
+                $entities->push($page);
+            }
+        }
+
+        if ($deleteOld) $this->deleteManyJointPermissionsForEntities($entities->all());
+        $this->createManyJointPermissions($entities, $roles);
     }
 
     /**
-     * Create the entity jointPermissions for a particular entity.
+     * Rebuild the entity jointPermissions for a particular entity.
      * @param Entity $entity
      */
     public function buildJointPermissionsForEntity(Entity $entity)
     {
-        $roles = $this->role->with('jointPermissions')->get();
-        $entities = collect([$entity]);
-
+        $entities = [$entity];
         if ($entity->isA('book')) {
-            $entities = $entities->merge($entity->chapters);
-            $entities = $entities->merge($entity->pages);
-        } elseif ($entity->isA('chapter')) {
-            $entities = $entities->merge($entity->pages);
+            $books = $this->bookFetchQuery()->where('id', '=', $entity->id)->get();
+            $this->buildJointPermissionsForBooks($books, $this->role->newQuery()->get(), true);
+            return;
         }
 
+        $entities[] = $entity->book;
+        if ($entity->isA('page') && $entity->chapter_id) $entities[] = $entity->chapter;
+        if ($entity->isA('chapter')) {
+            foreach ($entity->pages as $page) {
+                $entities[] = $page;
+            }
+        }
         $this->deleteManyJointPermissionsForEntities($entities);
+        $this->buildJointPermissionsForEntities(collect($entities));
+    }
+
+    /**
+     * Rebuild the entity jointPermissions for a collection of entities.
+     * @param Collection $entities
+     */
+    public function buildJointPermissionsForEntities(Collection $entities)
+    {
+        $roles = $this->role->newQuery()->get();
+        $this->deleteManyJointPermissionsForEntities($entities->all());
         $this->createManyJointPermissions($entities, $roles);
     }
 
@@ -122,23 +232,12 @@ class PermissionService
      */
     public function buildJointPermissionForRole(Role $role)
     {
-        $roles = collect([$role]);
-
+        $roles = [$role];
         $this->deleteManyJointPermissionsForRoles($roles);
 
         // Chunk through all books
-        $this->book->with('permissions')->chunk(500, function ($books) use ($roles) {
-            $this->createManyJointPermissions($books, $roles);
-        });
-
-        // Chunk through all chapters
-        $this->chapter->with('book', 'permissions')->chunk(500, function ($books) use ($roles) {
-            $this->createManyJointPermissions($books, $roles);
-        });
-
-        // Chunk through all pages
-        $this->page->with('book', 'chapter', 'permissions')->chunk(500, function ($books) use ($roles) {
-            $this->createManyJointPermissions($books, $roles);
+        $this->bookFetchQuery()->chunk(5, function ($books) use ($roles) {
+            $this->buildJointPermissionsForBooks($books, $roles);
         });
     }
 
@@ -157,9 +256,10 @@ class PermissionService
      */
     protected function deleteManyJointPermissionsForRoles($roles)
     {
-        foreach ($roles as $role) {
-            $role->jointPermissions()->delete();
-        }
+        $roleIds = array_map(function($role) {
+            return $role->id;
+        }, $roles);
+        $this->jointPermission->newQuery()->whereIn('id', $roleIds)->delete();
     }
 
     /**
@@ -177,47 +277,89 @@ class PermissionService
      */
     protected function deleteManyJointPermissionsForEntities($entities)
     {
-        foreach ($entities as $entity) {
-            $entity->jointPermissions()->delete();
-        }
+        if (count($entities) === 0) return;
+
+        $this->db->transaction(function() use ($entities) {
+
+            foreach (array_chunk($entities, 1000) as $entityChunk) {
+                $query = $this->db->table('joint_permissions');
+                foreach ($entityChunk as $entity) {
+                    $query->orWhere(function(QueryBuilder $query) use ($entity) {
+                        $query->where('entity_id', '=', $entity->id)
+                            ->where('entity_type', '=', $entity->getMorphClass());
+                    });
+                }
+                $query->delete();
+            }
+
+        });
     }
 
     /**
      * Create & Save entity jointPermissions for many entities and jointPermissions.
      * @param Collection $entities
-     * @param Collection $roles
+     * @param array $roles
      */
     protected function createManyJointPermissions($entities, $roles)
     {
+        $this->readyEntityCache();
         $jointPermissions = [];
+
+        // Fetch Entity Permissions and create a mapping of entity restricted statuses
+        $entityRestrictedMap = [];
+        $permissionFetch = $this->entityPermission->newQuery();
+        foreach ($entities as $entity) {
+            $entityRestrictedMap[$entity->getMorphClass() . ':' . $entity->id] = boolval($entity->getRawAttribute('restricted'));
+            $permissionFetch->orWhere(function($query) use ($entity) {
+                $query->where('restrictable_id', '=', $entity->id)->where('restrictable_type', '=', $entity->getMorphClass());
+            });
+        }
+        $permissions = $permissionFetch->get();
+
+        // Create a mapping of explicit entity permissions
+        $permissionMap = [];
+        foreach ($permissions as $permission) {
+            $key = $permission->restrictable_type . ':' . $permission->restrictable_id . ':' . $permission->role_id . ':' . $permission->action;
+            $isRestricted = $entityRestrictedMap[$permission->restrictable_type . ':' . $permission->restrictable_id];
+            $permissionMap[$key] = $isRestricted;
+        }
+
+        // Create a mapping of role permissions
+        $rolePermissionMap = [];
+        foreach ($roles as $role) {
+            foreach ($role->getRelationValue('permissions') as $permission) {
+                $rolePermissionMap[$role->getRawAttribute('id') . ':' . $permission->getRawAttribute('name')] = true;
+            }
+        }
+
+        // Create Joint Permission Data
         foreach ($entities as $entity) {
             foreach ($roles as $role) {
                 foreach ($this->getActions($entity) as $action) {
-                    $jointPermissions[] = $this->createJointPermissionData($entity, $role, $action);
+                    $jointPermissions[] = $this->createJointPermissionData($entity, $role, $action, $permissionMap, $rolePermissionMap);
                 }
             }
         }
-        $this->jointPermission->insert($jointPermissions);
+
+        $this->db->transaction(function() use ($jointPermissions) {
+            foreach (array_chunk($jointPermissions, 1000) as $jointPermissionChunk) {
+                $this->db->table('joint_permissions')->insert($jointPermissionChunk);
+            }
+        });
     }
 
 
     /**
      * Get the actions related to an entity.
-     * @param $entity
+     * @param Entity $entity
      * @return array
      */
-    protected function getActions($entity)
+    protected function getActions(Entity $entity)
     {
         $baseActions = ['view', 'update', 'delete'];
-
-        if ($entity->isA('chapter')) {
-            $baseActions[] = 'page-create';
-        } else if ($entity->isA('book')) {
-            $baseActions[] = 'page-create';
-            $baseActions[] = 'chapter-create';
-        }
-
-         return $baseActions;
+        if ($entity->isA('chapter') || $entity->isA('book')) $baseActions[] = 'page-create';
+        if ($entity->isA('book')) $baseActions[] = 'chapter-create';
+        return $baseActions;
     }
 
     /**
@@ -225,61 +367,63 @@ class PermissionService
      * for a particular action.
      * @param Entity $entity
      * @param Role $role
-     * @param $action
+     * @param string $action
+     * @param array $permissionMap
+     * @param array $rolePermissionMap
      * @return array
      */
-    protected function createJointPermissionData(Entity $entity, Role $role, $action)
+    protected function createJointPermissionData(Entity $entity, Role $role, $action, $permissionMap, $rolePermissionMap)
     {
         $permissionPrefix = (strpos($action, '-') === false ? ($entity->getType() . '-') : '') . $action;
-        $roleHasPermission = $role->hasPermission($permissionPrefix . '-all');
-        $roleHasPermissionOwn = $role->hasPermission($permissionPrefix . '-own');
+        $roleHasPermission = isset($rolePermissionMap[$role->getRawAttribute('id') . ':' . $permissionPrefix . '-all']);
+        $roleHasPermissionOwn = isset($rolePermissionMap[$role->getRawAttribute('id') . ':' . $permissionPrefix . '-own']);
         $explodedAction = explode('-', $action);
         $restrictionAction = end($explodedAction);
 
-        if ($entity->isA('book')) {
+        if ($role->system_name === 'admin') {
+            return $this->createJointPermissionDataArray($entity, $role, $action, true, true);
+        }
 
-            if (!$entity->restricted) {
-                return $this->createJointPermissionDataArray($entity, $role, $action, $roleHasPermission, $roleHasPermissionOwn);
-            } else {
-                $hasAccess = $entity->hasActiveRestriction($role->id, $restrictionAction);
-                return $this->createJointPermissionDataArray($entity, $role, $action, $hasAccess, $hasAccess);
-            }
+        if ($entity->restricted) {
+            $hasAccess = $this->mapHasActiveRestriction($permissionMap, $entity, $role, $restrictionAction);
+            return $this->createJointPermissionDataArray($entity, $role, $action, $hasAccess, $hasAccess);
+        }
 
-        } elseif ($entity->isA('chapter')) {
+        if ($entity->isA('book')) {
+            return $this->createJointPermissionDataArray($entity, $role, $action, $roleHasPermission, $roleHasPermissionOwn);
+        }
 
-            if (!$entity->restricted) {
-                $hasExplicitAccessToBook = $entity->book->hasActiveRestriction($role->id, $restrictionAction);
-                $hasPermissiveAccessToBook = !$entity->book->restricted;
-                return $this->createJointPermissionDataArray($entity, $role, $action,
-                    ($hasExplicitAccessToBook || ($roleHasPermission && $hasPermissiveAccessToBook)),
-                    ($hasExplicitAccessToBook || ($roleHasPermissionOwn && $hasPermissiveAccessToBook)));
-            } else {
-                $hasAccess = $entity->hasActiveRestriction($role->id, $restrictionAction);
-                return $this->createJointPermissionDataArray($entity, $role, $action, $hasAccess, $hasAccess);
+        // For chapters and pages, Check if explicit permissions are set on the Book.
+        $book = $this->getBook($entity->book_id);
+        $hasExplicitAccessToParents = $this->mapHasActiveRestriction($permissionMap, $book, $role, $restrictionAction);
+        $hasPermissiveAccessToParents = !$book->restricted;
+
+        // For pages with a chapter, Check if explicit permissions are set on the Chapter
+        if ($entity->isA('page') && $entity->chapter_id !== 0 && $entity->chapter_id !== '0') {
+            $chapter = $this->getChapter($entity->chapter_id);
+            $hasPermissiveAccessToParents = $hasPermissiveAccessToParents && !$chapter->restricted;
+            if ($chapter->restricted) {
+                $hasExplicitAccessToParents = $this->mapHasActiveRestriction($permissionMap, $chapter, $role, $restrictionAction);
             }
+        }
 
-        } elseif ($entity->isA('page')) {
-
-            if (!$entity->restricted) {
-                $hasExplicitAccessToBook = $entity->book->hasActiveRestriction($role->id, $restrictionAction);
-                $hasPermissiveAccessToBook = !$entity->book->restricted;
-                $hasExplicitAccessToChapter = $entity->chapter && $entity->chapter->hasActiveRestriction($role->id, $restrictionAction);
-                $hasPermissiveAccessToChapter = $entity->chapter && !$entity->chapter->restricted;
-                $acknowledgeChapter = ($entity->chapter && $entity->chapter->restricted);
-
-                $hasExplicitAccessToParents = $acknowledgeChapter ? $hasExplicitAccessToChapter : $hasExplicitAccessToBook;
-                $hasPermissiveAccessToParents = $acknowledgeChapter ? $hasPermissiveAccessToChapter : $hasPermissiveAccessToBook;
-
-                return $this->createJointPermissionDataArray($entity, $role, $action,
-                    ($hasExplicitAccessToParents || ($roleHasPermission && $hasPermissiveAccessToParents)),
-                    ($hasExplicitAccessToParents || ($roleHasPermissionOwn && $hasPermissiveAccessToParents))
-                );
-            } else {
-                $hasAccess = $entity->hasRestriction($role->id, $action);
-                return $this->createJointPermissionDataArray($entity, $role, $action, $hasAccess, $hasAccess);
-            }
+        return $this->createJointPermissionDataArray($entity, $role, $action,
+            ($hasExplicitAccessToParents || ($roleHasPermission && $hasPermissiveAccessToParents)),
+            ($hasExplicitAccessToParents || ($roleHasPermissionOwn && $hasPermissiveAccessToParents))
+        );
+    }
 
-        }
+    /**
+     * Check for an active restriction in an entity map.
+     * @param $entityMap
+     * @param Entity $entity
+     * @param Role $role
+     * @param $action
+     * @return bool
+     */
+    protected function mapHasActiveRestriction($entityMap, Entity $entity, Role $role, $action) {
+        $key = $entity->getMorphClass() . ':' . $entity->getRawAttribute('id') . ':' . $role->getRawAttribute('id') . ':' . $action;
+        return isset($entityMap[$key]) ? $entityMap[$key] : false;
     }
 
     /**
@@ -294,11 +438,10 @@ class PermissionService
      */
     protected function createJointPermissionDataArray(Entity $entity, Role $role, $action, $permissionAll, $permissionOwn)
     {
-        $entityClass = get_class($entity);
         return [
             'role_id'            => $role->getRawAttribute('id'),
             'entity_id'          => $entity->getRawAttribute('id'),
-            'entity_type'        => $entityClass,
+            'entity_type'        => $entity->getMorphClass(),
             'action'             => $action,
             'has_permission'     => $permissionAll,
             'has_permission_own' => $permissionOwn,
@@ -314,21 +457,25 @@ class PermissionService
      */
     public function checkOwnableUserAccess(Ownable $ownable, $permission)
     {
-        if ($this->isAdmin) return true;
+        if ($this->isAdmin()) {
+            $this->clean();
+            return true;
+        }
+
         $explodedPermission = explode('-', $permission);
 
         $baseQuery = $ownable->where('id', '=', $ownable->id);
         $action = end($explodedPermission);
         $this->currentAction = $action;
 
-        $nonJointPermissions = ['restrictions'];
+        $nonJointPermissions = ['restrictions', 'image', 'attachment', 'comment'];
 
         // Handle non entity specific jointPermissions
         if (in_array($explodedPermission[0], $nonJointPermissions)) {
-            $allPermission = $this->currentUser && $this->currentUser->can($permission . '-all');
-            $ownPermission = $this->currentUser && $this->currentUser->can($permission . '-own');
+            $allPermission = $this->currentUser() && $this->currentUser()->can($permission . '-all');
+            $ownPermission = $this->currentUser() && $this->currentUser()->can($permission . '-own');
             $this->currentAction = 'view';
-            $isOwner = $this->currentUser && $this->currentUser->id === $ownable->created_by;
+            $isOwner = $this->currentUser() && $this->currentUser()->id === $ownable->created_by;
             return ($allPermission || ($isOwner && $ownPermission));
         }
 
@@ -337,8 +484,9 @@ class PermissionService
             $this->currentAction = $permission;
         }
 
-
-        return $this->entityRestrictionQuery($baseQuery)->count() > 0;
+        $q = $this->entityRestrictionQuery($baseQuery)->count() > 0;
+        $this->clean();
+        return $q;
     }
 
     /**
@@ -368,7 +516,7 @@ class PermissionService
      */
     protected function entityRestrictionQuery($query)
     {
-        return $query->where(function ($parentQuery) {
+        $q = $query->where(function ($parentQuery) {
             $parentQuery->whereHas('jointPermissions', function ($permissionQuery) {
                 $permissionQuery->whereIn('role_id', $this->getRoles())
                     ->where('action', '=', $this->currentAction)
@@ -376,71 +524,84 @@ class PermissionService
                         $query->where('has_permission', '=', true)
                             ->orWhere(function ($query) {
                                 $query->where('has_permission_own', '=', true)
-                                    ->where('created_by', '=', $this->currentUser->id);
+                                    ->where('created_by', '=', $this->currentUser()->id);
                             });
                     });
             });
         });
+        $this->clean();
+        return $q;
     }
 
     /**
-     * Add restrictions for a page query
-     * @param $query
-     * @param string $action
-     * @return mixed
+     * Get the children of a book in an efficient single query, Filtered by the permission system.
+     * @param integer $book_id
+     * @param bool $filterDrafts
+     * @param bool $fetchPageContent
+     * @return QueryBuilder
      */
-    public function enforcePageRestrictions($query, $action = 'view')
-    {
-        // Prevent drafts being visible to others.
-        $query = $query->where(function ($query) {
-            $query->where('draft', '=', false);
-            if ($this->currentUser) {
-                $query->orWhere(function ($query) {
-                    $query->where('draft', '=', true)->where('created_by', '=', $this->currentUser->id);
+    public function bookChildrenQuery($book_id, $filterDrafts = false, $fetchPageContent = false) {
+        $pageSelect = $this->db->table('pages')->selectRaw($this->page->entityRawQuery($fetchPageContent))->where('book_id', '=', $book_id)->where(function($query) use ($filterDrafts) {
+            $query->where('draft', '=', 0);
+            if (!$filterDrafts) {
+                $query->orWhere(function($query) {
+                    $query->where('draft', '=', 1)->where('created_by', '=', $this->currentUser()->id);
                 });
             }
         });
+        $chapterSelect = $this->db->table('chapters')->selectRaw($this->chapter->entityRawQuery())->where('book_id', '=', $book_id);
+        $query = $this->db->query()->select('*')->from($this->db->raw("({$pageSelect->toSql()} UNION {$chapterSelect->toSql()}) AS U"))
+            ->mergeBindings($pageSelect)->mergeBindings($chapterSelect);
+
+        if (!$this->isAdmin()) {
+            $whereQuery = $this->db->table('joint_permissions as jp')->selectRaw('COUNT(*)')
+                ->whereRaw('jp.entity_id=U.id')->whereRaw('jp.entity_type=U.entity_type')
+                ->where('jp.action', '=', 'view')->whereIn('jp.role_id', $this->getRoles())
+                ->where(function($query) {
+                    $query->where('jp.has_permission', '=', 1)->orWhere(function($query) {
+                        $query->where('jp.has_permission_own', '=', 1)->where('jp.created_by', '=', $this->currentUser()->id);
+                    });
+                });
+            $query->whereRaw("({$whereQuery->toSql()}) > 0")->mergeBindings($whereQuery);
+        }
 
-        return $this->enforceEntityRestrictions($query, $action);
+        $query->orderBy('draft', 'desc')->orderBy('priority', 'asc');
+        $this->clean();
+        return  $query;
     }
 
     /**
-     * Add on permission restrictions to a chapter query.
-     * @param $query
+     * Add restrictions for a generic entity
+     * @param string $entityType
+     * @param Builder|Entity $query
      * @param string $action
-     * @return mixed
+     * @return Builder
      */
-    public function enforceChapterRestrictions($query, $action = 'view')
+    public function enforceEntityRestrictions($entityType, $query, $action = 'view')
     {
-        return $this->enforceEntityRestrictions($query, $action);
-    }
+        if (strtolower($entityType) === 'page') {
+            // Prevent drafts being visible to others.
+            $query = $query->where(function ($query) {
+                $query->where('draft', '=', false);
+                if ($this->currentUser()) {
+                    $query->orWhere(function ($query) {
+                        $query->where('draft', '=', true)->where('created_by', '=', $this->currentUser()->id);
+                    });
+                }
+            });
+        }
 
-    /**
-     * Add restrictions to a book query.
-     * @param $query
-     * @param string $action
-     * @return mixed
-     */
-    public function enforceBookRestrictions($query, $action = 'view')
-    {
-        return $this->enforceEntityRestrictions($query, $action);
-    }
+        if ($this->isAdmin()) {
+            $this->clean();
+            return $query;
+        }
 
-    /**
-     * Add restrictions for a generic entity
-     * @param $query
-     * @param string $action
-     * @return mixed
-     */
-    public function enforceEntityRestrictions($query, $action = 'view')
-    {
-        if ($this->isAdmin) return $query;
         $this->currentAction = $action;
         return $this->entityRestrictionQuery($query);
     }
 
     /**
-     * Filter items that have entities set a a polymorphic relation.
+     * Filter items that have entities set as a polymorphic relation.
      * @param $query
      * @param string $tableName
      * @param string $entityIdColumn
@@ -449,11 +610,15 @@ class PermissionService
      */
     public function filterRestrictedEntityRelations($query, $tableName, $entityIdColumn, $entityTypeColumn)
     {
-        if ($this->isAdmin) return $query;
+        if ($this->isAdmin()) {
+            $this->clean();
+            return $query;
+        }
+
         $this->currentAction = 'view';
         $tableDetails = ['tableName' => $tableName, 'entityIdColumn' => $entityIdColumn, 'entityTypeColumn' => $entityTypeColumn];
 
-        return $query->where(function ($query) use ($tableDetails) {
+        $q = $query->where(function ($query) use ($tableDetails) {
             $query->whereExists(function ($permissionQuery) use (&$tableDetails) {
                 $permissionQuery->select('id')->from('joint_permissions')
                     ->whereRaw('joint_permissions.entity_id=' . $tableDetails['tableName'] . '.' . $tableDetails['entityIdColumn'])
@@ -463,12 +628,13 @@ class PermissionService
                     ->where(function ($query) {
                         $query->where('has_permission', '=', true)->orWhere(function ($query) {
                             $query->where('has_permission_own', '=', true)
-                                ->where('created_by', '=', $this->currentUser->id);
+                                ->where('created_by', '=', $this->currentUser()->id);
                         });
                     });
             });
         });
-
+        $this->clean();
+        return $q;
     }
 
     /**
@@ -480,11 +646,15 @@ class PermissionService
      */
     public function filterRelatedPages($query, $tableName, $entityIdColumn)
     {
-        if ($this->isAdmin) return $query;
+        if ($this->isAdmin()) {
+            $this->clean();
+            return $query;
+        }
+
         $this->currentAction = 'view';
         $tableDetails = ['tableName' => $tableName, 'entityIdColumn' => $entityIdColumn];
 
-        return $query->where(function ($query) use ($tableDetails) {
+        $q = $query->where(function ($query) use ($tableDetails) {
             $query->where(function ($query) use (&$tableDetails) {
                 $query->whereExists(function ($permissionQuery) use (&$tableDetails) {
                     $permissionQuery->select('id')->from('joint_permissions')
@@ -495,12 +665,50 @@ class PermissionService
                         ->where(function ($query) {
                             $query->where('has_permission', '=', true)->orWhere(function ($query) {
                                 $query->where('has_permission_own', '=', true)
-                                    ->where('created_by', '=', $this->currentUser->id);
+                                    ->where('created_by', '=', $this->currentUser()->id);
                             });
                         });
                 });
             })->orWhere($tableDetails['entityIdColumn'], '=', 0);
         });
+        $this->clean();
+        return $q;
+    }
+
+    /**
+     * Check if the current user is an admin.
+     * @return bool
+     */
+    private function isAdmin()
+    {
+        if ($this->isAdminUser === null) {
+            $this->isAdminUser = ($this->currentUser()->id !== null) ? $this->currentUser()->hasSystemRole('admin') : false;
+        }
+
+        return $this->isAdminUser;
+    }
+
+    /**
+     * Get the current user
+     * @return User
+     */
+    private function currentUser()
+    {
+        if ($this->currentUserModel === false) {
+            $this->currentUserModel = user();
+        }
+
+        return $this->currentUserModel;
+    }
+
+    /**
+     * Clean the cached user elements.
+     */
+    private function clean()
+    {
+        $this->currentUserModel = false;
+        $this->userRoles = false;
+        $this->isAdminUser = null;
     }
 
 }
\ No newline at end of file