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Flash

class Cake\Controller\Component\FlashComponent(ComponentCollection $collection, array $config = [])

FlashComponent provides a way to set one-time notification messages to be displayed after processing a form or acknowledging data. CakePHP refers to these messages as “flash messages”. FlashComponent writes flash messages to $_SESSION, to be rendered in a View using FlashHelper.

Setting Flash Messages

FlashComponent provides two ways to set flash messages: its __call() magic method and its set() method. To furnish your application with verbosity, FlashComponent’s __call() magic method allows you use a method name that maps to an element located under the templates/element/flash directory. By convention, camelcased methods will map to the lowercased and underscored element name:

// Uses templates/element/flash/success.php
$this->Flash->success('This was successful');

// Uses templates/element/flash/great_success.php
$this->Flash->greatSuccess('This was greatly successful');

Alternatively, to set a plain-text message without rendering an element, you can use the set() method:

$this->Flash->set('This is a message');

Flash messages are appended to an array internally. Successive calls to set() or __call() with the same key will append the messages in the $_SESSION. If you want to overwrite existing messages when setting a flash message, set the clear option to true when configuring the Component.

FlashComponent’s __call() and set() methods optionally take a second parameter, an array of options:

  • key Defaults to ‘flash’. The array key found under the Flash key in the session.

  • element Defaults to null, but will automatically be set when using the __call() magic method. The element name to use for rendering.

  • params An optional array of keys/values to make available as variables within an element.

  • clear expects a bool and allows you to delete all messages in the current stack and start a new one.

An example of using these options:

// In your Controller
$this->Flash->success('The user has been saved', [
    'key' => 'positive',
    'clear' => true,
    'params' => [
        'name' => $user->name,
        'email' => $user->email
    ]
]);

// In your View
<?= $this->Flash->render('positive') ?>

<!-- In templates/element/flash/success.php -->
<div id="flash-<?= h($key) ?>" class="message-info success">
    <?= h($message) ?>: <?= h($params['name']) ?>, <?= h($params['email']) ?>.
</div>

Note that the parameter element will be always overridden while using __call(). In order to retrieve a specific element from a plugin, you should set the plugin parameter. For example:

// In your Controller
$this->Flash->warning('My message', ['plugin' => 'PluginName']);

The code above will use the warning.php element under plugins/PluginName/templates/element/flash for rendering the flash message.

Note

By default, CakePHP escapes the content in flash messages to prevent cross site scripting. User data in your flash messages will be HTML encoded and safe to be printed. If you want to include HTML in your flash messages, you need to pass the escape option and adjust your flash message templates to allow disabling escaping when the escape option is passed.

HTML in Flash Messages

It is possible to output HTML in flash messages by using the 'escape' option key:

$this->Flash->info(sprintf('<b>%s</b> %s', h($highlight), h($message)), ['escape' => false]);

Make sure that you escape the input manually, then. In the above example $highlight and $message are non-HTML input and therefore escaped.

For more information about rendering your flash messages, please refer to the FlashHelper section.