Validation rules are used by
Model::validate to check if attribute values are valid.
Child classes may override this method to declare different validation rules.
Each rule is an array with the following structure:
php
[
['attribute1', 'attribute2'],
'validator type',
'on' => ['scenario1', 'scenario2'],
...other parameters...
]
where
- attribute list: required, specifies the attributes array to be validated, for single attribute you can pass a string;
- validator type: required, specifies the validator to be used. It can be a built-in validator name,
a method name of the model class, an anonymous function, or a validator class name.
- on: optional, specifies the [[scenario|scenarios]] array in which the validation
rule can be applied. If this option is not set, the rule will apply to all scenarios.
- additional name-value pairs can be specified to initialize the corresponding validator properties.
Please refer to individual validator class API for possible properties.
A validator can be either an object of a class extending [[Validator]], or a model class method
(called *inline validator*) that has the following signature:
php
$params refers to validation parameters given in the rule
function validatorName($attribute, $params)
In the above
$attribute refers to the attribute currently being validated while
$params contains an array of
validator configuration options such as
max in case of
string validator. The value of the attribute currently being validated
can be accessed as
$this->$attribute. Note the
$ before
attribute; this is taking the value of the variable
$attribute and using it as the name of the property to access.
Yii also provides a set of [[Validator::builtInValidators|built-in validators]].
Each one has an alias name which can be used when specifying a validation rule.
Below are some examples:
php
[
built-in "required" validator
[['username', 'password'], 'required'],
built-in "string" validator customized with "min" and "max" properties
['username', 'string', 'min' => 3, 'max' => 12],
built-in "compare" validator that is used in "register" scenario only
['password', 'compare', 'compareAttribute' => 'password2', 'on' => 'register'],
an inline validator defined via the "authenticate()" method in the model class
['password', 'authenticate', 'on' => 'login'],
a validator of class "DateRangeValidator"
['dateRange', 'DateRangeValidator'],
];
Note, in order to inherit rules defined in the parent class, a child class needs to
merge the parent rules with child rules using functions such as
array_merge().
