Validating Data from the Controller¶

While normally you would just use the save method of the model, there may be times where you wish to validate the data without saving it. For example, you may wish to display some additional information to the user before actually saving the data to the database. Validating data requires a slightly different process than just saving the data.

First, set the data to the model:

$this->ModelName->set($this->request->data);

Then, to check if the data validates, use the validates method of the model, which will return true if it validates and false if it doesn’t:

if ($this->ModelName->validates()) {
    // it validated logic
} else {
    // didn't validate logic
    $errors = $this->ModelName->validationErrors;
}

It may be desirable to validate your model only using a subset of the validations specified in your model. For example say you had a User model with fields for first_name, last_name, email and password. In this instance when creating or editing a user you would want to validate all 4 field rules. Yet when a user logs in you would validate just email and password rules. To do this you can pass an options array specifying the fields to validate:

if ($this->User->validates(array('fieldList' => array('email', 'password')))) {
    // valid
} else {
    // invalid
}

The validates method invokes the invalidFields method which populates the validationErrors property of the model. The invalidFields method also returns that data as the result:

$errors = $this->ModelName->invalidFields(); // contains validationErrors array

The validation errors list is not cleared between successive calls to invalidFields() So if you are validating in a loop and want each set of errors separately don’t use invalidFields(). Instead use validates() and access the validationErrors model property.

It is important to note that the data must be set to the model before the data can be validated. This is different from the save method which allows the data to be passed in as a parameter. Also, keep in mind that it is not required to call validates prior to calling save as save will automatically validate the data before actually saving.

To validate multiple models, the following approach should be used:

if ($this->ModelName->saveAll(
    $this->request->data, array('validate' => 'only')
)) {
  // validates
} else {
  // does not validate
}

If you have validated data before save, you can turn off validation to avoid second check:

if ($this->ModelName->saveAll(
    $this->request->data, array('validate' => false)
)) {
    // saving without validation
}