Set unique rule to a field on update action on yii2 rest - rest

Question

I am creating a rest api with yii2 to create and update user information. Below is the rule function in the model class.
public function rules()
{
return [
[['name', 'emailId', 'contactNumber'], 'required'],
[['name', 'emailId', 'contactNumber'], 'string', 'max' => 255]
[['emailId', 'username', 'contactNumber'], 'unique'],
['status', 'default', 'value' => self::STATUS_ACTIVE],
['status', 'in', 'range' => [self::STATUS_ACTIVE, self::STATUS_DELETED]]
];
}
Here I mentioned emailId, username, contactNumber fields should be unique. When I try to create, it is checking whether the field is unique or not. if unique it is throwing the error else it is saving. That is fine.
But when I try to update the value there also it is checking the particular value for the field is unique or not. But it should not be like that. The unique validation should not work on update action. So I updated the rule with 'on'=>'update' as like Yii 1. Check the below function.
public function rules()
{
return [
[['name', 'emailId', 'contactNumber'], 'required'],
[['name', 'emailId', 'contactNumber'], 'string', 'max' => 255]
[['emailId', 'username', 'contactNumber'], 'unique', 'on'=>'update'],
['status', 'default', 'value' => self::STATUS_ACTIVE],
['status', 'in', 'range' => [self::STATUS_ACTIVE, self::STATUS_DELETED]]
];
}
But when i check the official documentation there is no option like on to check the particular action. When i use 'on'=>'update', both(while creating and update) places it is not validating. Might be because of the on. Just leave that. I need to add unique validation for those fields in create action only not in update action.
So, Please anybody help me with how to add unique validation to those fields only in create action.
Thanks.

Answer 1

You can set scenario for your REST actions in your ActiveController:
public function actions()
{
$actions = parent::actions();
$actions['update']['scenario'] = 'update';
$actions['create']['scenario'] = 'create';
return $actions;
}
And then use it in rules:
[['emailId', 'username', 'contactNumber'], 'unique', 'on'=>'create']
Also you must specify list of active attributes for each scenario in the particular model class:
public function scenarios()
{
$scenarios = parent::scenarios();
$scenarios['update'] = ['type', 'title', 'description'];
$scenarios['create'] = ['type', 'title', 'description', 'affiliate_id'];
return $scenarios;
}