What’s wrong with this multiple Model Validation rule? Will both, one, or neither rule be executed and why? How might this code be fixed?
'email' => array( 'rule' => array( 'rule' => 'notEmpty', 'message' => 'Email address is required.' ), 'rule' => array( 'rule' => 'email', 'message' => 'The email address you entered is invalid.' ) )
'rule' needs to be unique when calling multiple validation rules. In the case above, the
notEmpty rule will never be called, as the
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.' ) )
What is the purpose of
$this->set(); when used in the Controller actions, e.g:
Also, compare the above line of code to the following:
What are the relative advantages of each? Which would you use and why?
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
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.
In the following line of code, how could the
Containable behavior be used to optimize the
find query so that only the
region data is returned (i.e., without any model associations):
Containable behavior allows the developer to specify which associated models (if any) are retrieved from the
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));
A current alternative to the
Containable behavior is to use the
recursive function. Why is the use of the
recursive function below incorrect in a case where we want to only retrieve the region data without any model associations?
$this->Region->find('all', array('recursive' => 0));
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
0– Retrieves any
1– Retrieves any directly related associations (i.e.,
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
What is the difference between a Component, a Behavior, and a Helper? Provide an example of where and when each might be used.
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.
- A shopping cart
Componentmight offer functionality that can be used and shared across multiple Controllers.
- A custom upload
Behaviorcould be used to extend a Model, such as this example for uploading images. Another common example of a
Behaviorwould be to add extra validation functionality beyond that which CakePHP offers by default.
Helpercan 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.