5 Essential CakePHP Interview Questions *

The key 'rule' needs to be unique when calling multiple validation rules. In the case above, the notEmpty rule will never be called, as the email rule will simply overwrite it (since the multidimensional array has the same key).

Each key should be unique, e.g:

'email' => array(
    'rule-1' => array(
        'rule' => 'notEmpty',
        'message' => 'Email address is required.
    ),
    'rule-2' => array(
        'rule' => 'email',
        'message' => 'The email address you entered is invalid.'
    )
)

The set() method is used to create a variable in the view file. In the example above, the variable $articles will then be available to use in the view template file for that action.

An advantage of the first example (i.e., $this->set('articles', $articles); is that it allows the variable name on the view to be different from the variable name on the controller. For example, if you wanted them to be different, you could do something like $this->set('articlesData', $articles);. The variable on the view file would then be $articlesData.

The advantage of the second approach (i.e., $this->set(compact('articles'));, on the other hand, is that it is somewhat neater, and it also is arguably a bit less error-prone. It is also shorter and easier to write, especially where we are setting several variables to the view.

The Containable behavior allows the developer to specify which associated models (if any) are retrieved from the find query.

So to ensure that no other associated models are returned in the above example, it could simply be re-written as:

$this->Region->find('all', array('contain' => false));

The use of recursive is incorrect in the above example (if we don’t want to pull any associated data) since recursive works as follows:

• -1 – No associated data is retrieved with the find query.
• ` 0 – Retrieves any BelongsTo` associated data.
• ` 1 – Retrieves any directly related associations (i.e., BelongsTo, HasMany, HasOne, HasAndBelongsToMany`).
• ` 2` – Retrieves any directly related associations, and their associations’ associations.

So in the above, example, -1 should have been used (rather than 0) to avoid pulling any associated data.

It is also important to note that recursive is slated to be phased out in CakePHP 3 and replaced solely with the Containable behavior.

All 3 are similar because they act to extend existing CakePHP functionality, but the differ on what they extend:

• A Component is used to extend a Controller
• A Behavior is used to extend a Model
• A Helper is used to extend a View.

For example:

• A shopping cart Component might offer functionality that can be used and shared across multiple Controllers.
• A custom upload Behavior could be used to extend a Model, for example to add images uploads. Another common example of a Behavior would be to add extra validation functionality beyond that which CakePHP offers by default.
• A Helper can be used to assist with View functionality. A good example here would be the CK Editor helper that makes it easy to display a CK Editor.