Bookmarker Tutorial Part 2

After finishing the first part of this tutorial you should have a very basic bookmarking application. In this chapter we’ll be adding authentication and restricting the bookmarks each user can see/modify to only the ones they own.

Adding Login

In CakePHP, authentication is handled by Components. Components can be thought of as ways to create reusable chunks of controller code related to a specific feature or concept. Components can also hook into the controller’s event life-cycle and interact with your application that way. To get started, we’ll add the AuthComponent to our application. We’ll pretty much want every method to require authentication, so we’ll add AuthComponent in our AppController:

// In src/Controller/AppController.php
namespace App\Controller;

use Cake\Controller\Controller;

class AppController extends Controller
{
    public function initialize()
    {
        $this->loadComponent('Flash');
        $this->loadComponent('Auth', [
            'authenticate' => [
                'Form' => [
                    'fields' => [
                        'username' => 'email',
                        'password' => 'password'
                    ]
                ]
            ],
            'loginAction' => [
                'controller' => 'Users',
                'action' => 'login'
            ],
            'unauthorizedRedirect' => $this->referer() // If unauthorized, return them to page they were just on
        ]);

        // Allow the display action so our pages controller
        // continues to work.
        $this->Auth->allow(['display']);
    }
}

We’ve just told CakePHP that we want to load the Flash and Auth components. In addition, we’ve customized the configuration of AuthComponent, as our users table uses email as the username. Now, if you go to any URL you’ll be kicked to /users/login, which will show an error page as we have not written that code yet. So let’s create the login action:

// In src/Controller/UsersController.php
public function login()
{
    if ($this->request->is('post')) {
        $user = $this->Auth->identify();
        if ($user) {
            $this->Auth->setUser($user);
            return $this->redirect($this->Auth->redirectUrl());
        }
        $this->Flash->error('Your username or password is incorrect.');
    }
}

And in src/Template/Users/login.ctp add the following:

<h1>Login</h1>
<?= $this->Form->create() ?>
<?= $this->Form->control('email') ?>
<?= $this->Form->control('password') ?>
<?= $this->Form->button('Login') ?>
<?= $this->Form->end() ?>

Note

The control() method is available since 3.4. For prior versions you can use the input() method instead.

Now that we have a simple login form, we should be able to log in with one of the users that has a hashed password.

Note

If none of your users have hashed passwords, comment the loadComponent('Auth') line. Then go and edit the user, saving a new password for them.

You should now be able to log in. If not, make sure you are using a user that has a hashed password.

Adding Logout

Now that people can log in, you’ll probably want to provide a way to log out as well. Again, in the UsersController, add the following code:

public function initialize()
{
    parent::initialize();
    $this->Auth->allow(['logout']);
}

public function logout()
{
    $this->Flash->success('You are now logged out.');
    return $this->redirect($this->Auth->logout());
}

This code whitelists the logout action as a public action, and implements the logout method. Now you can visit /users/logout to log out. You should then be sent to the login page.

Enabling Registrations

If you aren’t logged in and you try to visit /users/add you will be kicked to the login page. We should fix that as we want to allow people to sign up for our application. In the UsersController add the following:

public function initialize()
{
    parent::initialize();
    // Add logout to the allowed actions list.
    $this->Auth->allow(['logout', 'add']);
}

The above tells AuthComponent that the add() action does not require authentication or authorization. You may want to take the time to clean up the Users/add.ctp and remove the misleading links, or continue on to the next section. We won’t be building out user editing, viewing or listing in this tutorial so they will not work as AuthComponent will deny you access to those controller actions.

Restricting Bookmark Access

Now that users can log in, we’ll want to limit the bookmarks they can see to the ones they made. We’ll do this using an ‘authorization’ adapter. Since our requirements are pretty simple, we can write some simple code in our BookmarksController. But before we do that, we’ll want to tell the AuthComponent how our application is going to authorize actions. In your AppController add the following:

public function isAuthorized($user)
{
    return false;
}

Also, add the following to the configuration for Auth in your AppController:

'authorize' => 'Controller',

Your initialize() method should now look like:

public function initialize()
{
    $this->loadComponent('Flash');
    $this->loadComponent('Auth', [
        'authorize'=> 'Controller',//added this line
        'authenticate' => [
            'Form' => [
                'fields' => [
                    'username' => 'email',
                    'password' => 'password'
                ]
            ]
        ],
        'loginAction' => [
            'controller' => 'Users',
            'action' => 'login'
        ],
        'unauthorizedRedirect' => $this->referer()
    ]);

    // Allow the display action so our pages controller
    // continues to work.
    $this->Auth->allow(['display']);
}

We’ll default to denying access, and incrementally grant access where it makes sense. First, we’ll add the authorization logic for bookmarks. In your BookmarksController add the following:

public function isAuthorized($user)
{
    $action = $this->request->getParam('action');

    // The add and index actions are always allowed.
    if (in_array($action, ['index', 'add', 'tags'])) {
        return true;
    }
    // All other actions require an id.
    if (!$this->request->getParam('pass.0')) {
        return false;
    }

    // Check that the bookmark belongs to the current user.
    $id = $this->request->getParam('pass.0');
    $bookmark = $this->Bookmarks->get($id);
    if ($bookmark->user_id == $user['id']) {
        return true;
    }
    return parent::isAuthorized($user);
}

Now if you try to view, edit or delete a bookmark that does not belong to you, you should be redirected back to the page you came from. If no error message is displayed, add the following to your layout:

// In src/Template/Layout/default.ctp
<?= $this->Flash->render() ?>

You should now see the authorization error messages.

Fixing List view and Forms

While view and delete are working, edit, add and index have a few problems:

  1. When adding a bookmark you can choose the user.
  2. When editing a bookmark you can choose the user.
  3. The list page shows bookmarks from other users.

Let’s tackle the add form first. To begin with remove the control('user_id') from src/Template/Bookmarks/add.ctp. With that removed, we’ll also update the add() action from src/Controller/BookmarksController.php to look like:

public function add()
{
    $bookmark = $this->Bookmarks->newEntity();
    if ($this->request->is('post')) {
        $bookmark = $this->Bookmarks->patchEntity($bookmark, $this->request->getData());
        $bookmark->user_id = $this->Auth->user('id');
        if ($this->Bookmarks->save($bookmark)) {
            $this->Flash->success('The bookmark has been saved.');
            return $this->redirect(['action' => 'index']);
        }
        $this->Flash->error('The bookmark could not be saved. Please, try again.');
    }
    $tags = $this->Bookmarks->Tags->find('list');
    $this->set(compact('bookmark', 'tags'));
    $this->set('_serialize', ['bookmark']);
}

By setting the entity property with the session data, we remove any possibility of the user modifying which user a bookmark is for. We’ll do the same for the edit form and action. Your edit() action from src/Controller/BookmarksController.php should look like:

public function edit($id = null)
{
    $bookmark = $this->Bookmarks->get($id, [
        'contain' => ['Tags']
    ]);
    if ($this->request->is(['patch', 'post', 'put'])) {
        $bookmark = $this->Bookmarks->patchEntity($bookmark, $this->request->getData());
        $bookmark->user_id = $this->Auth->user('id');
        if ($this->Bookmarks->save($bookmark)) {
            $this->Flash->success('The bookmark has been saved.');
            return $this->redirect(['action' => 'index']);
        }
        $this->Flash->error('The bookmark could not be saved. Please, try again.');
    }
    $tags = $this->Bookmarks->Tags->find('list');
    $this->set(compact('bookmark', 'tags'));
    $this->set('_serialize', ['bookmark']);
}

List View

Now, we only need to show bookmarks for the currently logged in user. We can do that by updating the call to paginate(). Make your index() action from src/Controller/BookmarksController.php look like:

public function index()
{
    $this->paginate = [
        'conditions' => [
            'Bookmarks.user_id' => $this->Auth->user('id'),
        ]
    ];
    $this->set('bookmarks', $this->paginate($this->Bookmarks));
    $this->set('_serialize', ['bookmarks']);
}

We should also update the tags() action and the related finder method, but we’ll leave that as an exercise you can complete on your own.

Improving the Tagging Experience

Right now, adding new tags is a difficult process, as the TagsController disallows all access. Instead of allowing access, we can improve the tag selection UI by using a comma separated text field. This will let us give a better experience to our users, and use some more great features in the ORM.

Adding a Computed Field

Because we’ll want a simple way to access the formatted tags for an entity, we can add a virtual/computed field to the entity. In src/Model/Entity/Bookmark.php add the following:

use Cake\Collection\Collection;

protected function _getTagString()
{
    if (isset($this->_properties['tag_string'])) {
        return $this->_properties['tag_string'];
    }
    if (empty($this->tags)) {
        return '';
    }
    $tags = new Collection($this->tags);
    $str = $tags->reduce(function ($string, $tag) {
        return $string . $tag->title . ', ';
    }, '');
    return trim($str, ', ');
}

This will let us access the $bookmark->tag_string computed property. We’ll use this property in controls later on. Remember to add the tag_string property to the _accessible list in your entity, as we’ll want to ‘save’ it later on.

In src/Model/Entity/Bookmark.php add the tag_string to $_accessible this way:

protected $_accessible = [
    'user_id' => true,
    'title' => true,
    'description' => true,
    'url' => true,
    'user' => true,
    'tags' => true,
    'tag_string' => true,
];

Updating the Views

With the entity updated we can add a new control for our tags. In src/Template/Bookmarks/add.ctp and src/Template/Bookmarks/edit.ctp, replace the existing tags._ids control with the following:

echo $this->Form->control('tag_string', ['type' => 'text']);

Persisting the Tag String

Now that we can view existing tags as a string, we’ll want to save that data as well. Because we marked the tag_string as accessible, the ORM will copy that data from the request into our entity. We can use a beforeSave() hook method to parse the tag string and find/build the related entities. Add the following to src/Model/Table/BookmarksTable.php:

public function beforeSave($event, $entity, $options)
{
    if ($entity->tag_string) {
        $entity->tags = $this->_buildTags($entity->tag_string);
    }
}

protected function _buildTags($tagString)
{
    // Trim tags
    $newTags = array_map('trim', explode(',', $tagString));
    // Remove all empty tags
    $newTags = array_filter($newTags);
    // Reduce duplicated tags
    $newTags = array_unique($newTags);

    $out = [];
    $query = $this->Tags->find()
        ->where(['Tags.title IN' => $newTags]);

    // Remove existing tags from the list of new tags.
    foreach ($query->extract('title') as $existing) {
        $index = array_search($existing, $newTags);
        if ($index !== false) {
            unset($newTags[$index]);
        }
    }
    // Add existing tags.
    foreach ($query as $tag) {
        $out[] = $tag;
    }
    // Add new tags.
    foreach ($newTags as $tag) {
        $out[] = $this->Tags->newEntity(['title' => $tag]);
    }
    return $out;
}

While this code is a bit more complicated than what we’ve done so far, it helps to showcase how powerful the ORM in CakePHP is. You can manipulate query results using the Collections methods, and handle scenarios where you are creating entities on the fly with ease.

Wrapping Up

We’ve expanded our bookmarking application to handle authentication and basic authorization/access control scenarios. We’ve also added some nice UX improvements by leveraging the FormHelper and ORM capabilities.

Thanks for taking the time to explore CakePHP. Next, you can complete the Blog Tutorial, learn more about the Database Access & ORM, or you can peruse the Using CakePHP.