CMS Tutorial - Creating the Articles Controller¶

Create the Article List Template¶

Now that we have our controller pulling data from the model, and preparing our view context, let’s create a view template for our index action.

CakePHP view templates are presentation-flavored PHP code that is inserted inside the application’s layout. While we’ll be creating HTML here, Views can also generate JSON, CSV or even binary files like PDFs.

A layout is presentation code that is wrapped around a view. Layout files contain common site elements like headers, footers and navigation elements. Your application can have multiple layouts, and you can switch between them, but for now, let’s just use the default layout.

CakePHP’s template files are stored in src/Template inside a folder named after the controller they correspond to. So we’ll have to create a folder named ‘Articles’ in this case. Add the following code to your application:

<!-- File: src/Template/Articles/index.ctp -->

<h1>Articles</h1>
<table>
    <tr>
        <th>Title</th>
        <th>Created</th>
    </tr>

    <!-- Here is where we iterate through our $articles query object, printing out article info -->

    <?php foreach ($articles as $article): ?>
    <tr>
        <td>
            <?= $this->Html->link($article->title, ['action' => 'view', $article->slug]) ?>
        </td>
        <td>
            <?= $article->created->format(DATE_RFC850) ?>
        </td>
    </tr>
    <?php endforeach; ?>
</table>

In the last section we assigned the ‘articles’ variable to the view using set(). Variables passed into the view are available in the view templates as local variables which we used in the above code.

You might have noticed the use of an object called $this->Html. This is an instance of the CakePHP HtmlHelper. CakePHP comes with a set of view helpers that make tasks like creating links, forms, and pagination buttons easy. You can learn more about Helpers in their chapter, but what’s important to note here is that the link() method will generate an HTML link with the given link text (the first parameter) and URL (the second parameter).

When specifying URLs in CakePHP, it is recommended that you use arrays or named routes. These syntaxes allow you to leverage the reverse routing features CakePHP offers.

At this point, you should be able to point your browser to http://localhost:8765/articles/index. You should see your list view, correctly formatted with the title and table listing of the articles.

Create the View Action¶

If you were to click one of the ‘view’ links in our Articles list page, you’d see an error page saying that action hasn’t been implemented. Lets fix that now:

// Add to existing src/Controller/ArticlesController.php file

public function view($slug = null)
{
    $article = $this->Articles->findBySlug($slug)->firstOrFail();
    $this->set(compact('article'));
}

While this is a simple action, we’ve used some powerful CakePHP features. We start our action off by using findBySlug() which is a Dynamic Finder. This method allows us to create a basic query that finds articles by a given slug. We then use firstOrFail() to either fetch the first record, or throw a NotFoundException.

Our action takes a $slug parameter, but where does that parameter come from? If a user requests /articles/view/first-post, then the value ‘first-post’ is passed as $slug by CakePHP’s routing and dispatching layers. If we reload our browser with our new action saved, we’d see another CakePHP error page telling us we’re missing a view template; let’s fix that.

Create the View Template¶

Let’s create the view for our new ‘view’ action and place it in src/Template/Articles/view.ctp

<!-- File: src/Template/Articles/view.ctp -->

<h1><?= h($article->title) ?></h1>
<p><?= h($article->body) ?></p>
<p><small>Created: <?= $article->created->format(DATE_RFC850) ?></small></p>
<p><?= $this->Html->link('Edit', ['action' => 'edit', $article->slug]) ?></p>

You can verify that this is working by trying the links at /articles/index or manually requesting an article by accessing URLs like /articles/view/first-post.

Adding Articles¶

With the basic read views created, we need to make it possible for new articles to be created. Start by creating an add() action in the ArticlesController. Our controller should now look like:

// src/Controller/ArticlesController.php

namespace App\Controller;

use App\Controller\AppController;

class ArticlesController extends AppController
{
    public function initialize()
    {
        parent::initialize();

        $this->loadComponent('Paginator');
        $this->loadComponent('Flash'); // Include the FlashComponent
    }

    public function index()
    {
        $articles = $this->Paginator->paginate($this->Articles->find());
        $this->set(compact('articles'));
    }

    public function view($slug)
    {
        $article = $this->Articles->findBySlug($slug)->firstOrFail();
        $this->set(compact('article'));
    }

    public function add()
    {
        $article = $this->Articles->newEntity();
        if ($this->request->is('post')) {
            $article = $this->Articles->patchEntity($article, $this->request->getData());

            // Hardcoding the user_id is temporary, and will be removed later
            // when we build authentication out.
            $article->user_id = 1;

            if ($this->Articles->save($article)) {
                $this->Flash->success(__('Your article has been saved.'));
                return $this->redirect(['action' => 'index']);
            }
            $this->Flash->error(__('Unable to add your article.'));
        }
        $this->set('article', $article);
    }
}

Here’s what the add() action does:

• If the HTTP method of the request was POST, try to save the data using the Articles model.

• If for some reason it doesn’t save, just render the view. This gives us a chance to show the user validation errors or other warnings.

Every CakePHP request includes a request object which is accessible using $this->request. The request object contains information regarding the request that was just received. We use the Cake\Http\ServerRequest::is() method to check that the request is a HTTP POST request.

Our POST data is available in $this->request->getData(). You can use the pr() or debug() functions to print it out if you want to see what it looks like. To save our data, we first ‘marshal’ the POST data into an Article Entity. The Entity is then persisted using the ArticlesTable we created earlier.

After saving our new article we use FlashComponent’s success() method to set a message into the session. The success method is provided using PHP’s magic method features. Flash messages will be displayed on the next page after redirecting. In our layout we have <?= $this->Flash->render() ?> which displays flash messages and clears the corresponding session variable. Finally, after saving is complete, we use Cake\Controller\Controller::redirect to send the user back to the articles list. The param ['action' => 'index'] translates to URL /articles i.e the index action of the ArticlesController. You can refer to Cake\Routing\Router::url() function on the API to see the formats in which you can specify a URL for various CakePHP functions.

Create Add Template¶

Here’s our add view template:

<!-- File: src/Template/Articles/add.ctp -->

<h1>Add Article</h1>
<?php
    echo $this->Form->create($article);
    // Hard code the user for now.
    echo $this->Form->control('user_id', ['type' => 'hidden', 'value' => 1]);
    echo $this->Form->control('title');
    echo $this->Form->control('body', ['rows' => '3']);
    echo $this->Form->button(__('Save Article'));
    echo $this->Form->end();
?>

We use the FormHelper to generate the opening tag for an HTML form. Here’s the HTML that $this->Form->create() generates:

<form method="post" action="/articles/add">

Because we called create() without a URL option, FormHelper assumes we want the form to submit back to the current action.

The $this->Form->control() method is used to create form elements of the same name. The first parameter tells CakePHP which field they correspond to, and the second parameter allows you to specify a wide array of options - in this case, the number of rows for the textarea. There’s a bit of introspection and conventions used here. The control() will output different form elements based on the model field specified, and use inflection to generate the label text. You can customize the label, the input or any other aspect of the form controls using options. The $this->Form->end() call closes the form.

Now let’s go back and update our src/Template/Articles/index.ctp view to include a new “Add Article” link. Before the <table>, add the following line:

<?= $this->Html->link('Add Article', ['action' => 'add']) ?>

Adding Simple Slug Generation¶

If we were to save an Article right now, saving would fail as we are not creating a slug attribute, and the column is NOT NULL. Slug values are typically a URL-safe version of an article’s title. We can use the beforeSave() callback of the ORM to populate our slug:

// in src/Model/Table/ArticlesTable.php
namespace App\Model\Table;

use Cake\ORM\Table;
// the Text class
use Cake\Utility\Text;

// Add the following method.

public function beforeSave($event, $entity, $options)
{
    if ($entity->isNew() && !$entity->slug) {
        $sluggedTitle = Text::slug($entity->title);
        // trim slug to maximum length defined in schema
        $entity->slug = substr($sluggedTitle, 0, 191);
    }
}

This code is simple, and doesn’t take into account duplicate slugs. But we’ll fix that later on.

Add Edit Action¶

Our application can now save articles, but we can’t edit them. Lets rectify that now. Add the following action to your ArticlesController:

// in src/Controller/ArticlesController.php

// Add the following method.

public function edit($slug)
{
    $article = $this->Articles->findBySlug($slug)->firstOrFail();
    if ($this->request->is(['post', 'put'])) {
        $this->Articles->patchEntity($article, $this->request->getData());
        if ($this->Articles->save($article)) {
            $this->Flash->success(__('Your article has been updated.'));
            return $this->redirect(['action' => 'index']);
        }
        $this->Flash->error(__('Unable to update your article.'));
    }

    $this->set('article', $article);
}

This action first ensures that the user has tried to access an existing record. If they haven’t passed in an $slug parameter, or the article does not exist, a NotFoundException will be thrown, and the CakePHP ErrorHandler will render the appropriate error page.

Next the action checks whether the request is either a POST or a PUT request. If it is, then we use the POST/PUT data to update our article entity by using the patchEntity() method. Finally, we call save() set the appropriate flash message and either redirect or display validation errors.

Create Edit Template¶

The edit template should look like this:

<!-- File: src/Template/Articles/edit.ctp -->

<h1>Edit Article</h1>
<?php
    echo $this->Form->create($article);
    echo $this->Form->control('user_id', ['type' => 'hidden']);
    echo $this->Form->control('title');
    echo $this->Form->control('body', ['rows' => '3']);
    echo $this->Form->button(__('Save Article'));
    echo $this->Form->end();
?>

This template outputs the edit form (with the values populated), along with any necessary validation error messages.

You can now update your index view with links to edit specific articles:

<!-- File: src/Template/Articles/index.ctp  (edit links added) -->

<h1>Articles</h1>
<p><?= $this->Html->link("Add Article", ['action' => 'add']) ?></p>
<table>
    <tr>
        <th>Title</th>
        <th>Created</th>
        <th>Action</th>
    </tr>

<!-- Here's where we iterate through our $articles query object, printing out article info -->

<?php foreach ($articles as $article): ?>
    <tr>
        <td>
            <?= $this->Html->link($article->title, ['action' => 'view', $article->slug]) ?>
        </td>
        <td>
            <?= $article->created->format(DATE_RFC850) ?>
        </td>
        <td>
            <?= $this->Html->link('Edit', ['action' => 'edit', $article->slug]) ?>
        </td>
    </tr>
<?php endforeach; ?>

</table>

Update Validation Rules for Articles¶

Up until this point our Articles had no input validation done. Lets fix that by using a validator:

// src/Model/Table/ArticlesTable.php

// add this use statement right below the namespace declaration to import
// the Validator class
use Cake\Validation\Validator;

// Add the following method.
public function validationDefault(Validator $validator)
{
    $validator
        ->allowEmptyString('title', 'Title cannot be empty', false)
        ->minLength('title', 10)
        ->maxLength('title', 255);

    $validator
        ->allowEmptyString('body', 'Body cannot be empty', false)
        ->minLength('body', 10);

    return $validator;
}

The validationDefault() method tells CakePHP how to validate your data when the save() method is called. Here, we’ve specified that both the title, and body fields must not be empty, and have certain length constraints.

CakePHP’s validation engine is powerful and flexible. It provides a suite of frequently used rules for tasks like email addresses, IP addresses etc. and the flexibility for adding your own validation rules. For more information on that setup, check the Validation documentation.

Now that your validation rules are in place, use the app to try to add an article with an empty title or body to see how it works. Since we’ve used the Cake\View\Helper\FormHelper::control() method of the FormHelper to create our form elements, our validation error messages will be shown automatically.

Add Delete Action¶

Next, let’s make a way for users to delete articles. Start with a delete() action in the ArticlesController:

// src/Controller/ArticlesController.php

public function delete($slug)
{
    $this->request->allowMethod(['post', 'delete']);

    $article = $this->Articles->findBySlug($slug)->firstOrFail();
    if ($this->Articles->delete($article)) {
        $this->Flash->success(__('The {0} article has been deleted.', $article->title));
        return $this->redirect(['action' => 'index']);
    }
}

This logic deletes the article specified by $slug, and uses $this->Flash->success() to show the user a confirmation message after redirecting them to /articles. If the user attempts to delete an article using a GET request, allowMethod() will throw an exception. Uncaught exceptions are captured by CakePHP’s exception handler, and a nice error page is displayed. There are many built-in Exceptions that can be used to indicate the various HTTP errors your application might need to generate.

Because we’re only executing logic and redirecting to another action, this action has no template. You might want to update your index template with links that allow users to delete articles:

<!-- File: src/Template/Articles/index.ctp  (delete links added) -->

<h1>Articles</h1>
<p><?= $this->Html->link("Add Article", ['action' => 'add']) ?></p>
<table>
    <tr>
        <th>Title</th>
        <th>Created</th>
        <th>Action</th>
    </tr>

<!-- Here's where we iterate through our $articles query object, printing out article info -->

<?php foreach ($articles as $article): ?>
    <tr>
        <td>
            <?= $this->Html->link($article->title, ['action' => 'view', $article->slug]) ?>
        </td>
        <td>
            <?= $article->created->format(DATE_RFC850) ?>
        </td>
        <td>
            <?= $this->Html->link('Edit', ['action' => 'edit', $article->slug]) ?>
            <?= $this->Form->postLink(
                'Delete',
                ['action' => 'delete', $article->slug],
                ['confirm' => 'Are you sure?'])
            ?>
        </td>
    </tr>
<?php endforeach; ?>

</table>

Using postLink() will create a link that uses JavaScript to do a POST request deleting our article.

With a basic articles management setup, we’ll create the basic actions for our Tags and Users tables.