Yii2, why a model validation fails due to a missing mandatory attribute when that attribute is assigned by a Behavior?

Question

I have a Model with a
[['creation_time'], 'integer'] attribute which have a

[
    'class' => TimestampBehavior::className(),
    'createdAtAttribute' => 'creation_time'
]

behavior assigned.
If I mark this attribute as required it'll fail the model validation as if it's missing.
Why?
How can I mark it as required?

in the model rules [['creation_time'], 'required'], make it required, or you can set a scenario.. — Sfili_81, Oct 29 '19 at 08:59
@Sfili_81 have you read the question? If I do that it will fail the validation — Zhigalin - Reinstate CMs, Oct 29 '19 at 09:10
If a field is required it's obvious that validation fails. probably is unclear what do you want to achieve — Sfili_81, Oct 29 '19 at 09:17
@Sfili_81 it's not obvious because it should be assigned by the behavior — Zhigalin - Reinstate CMs, Oct 29 '19 at 09:19
[https://www.yiiframework.com/doc/guide/2.0/en/concept-behaviors#using-timestamp-behavior](https://www.yiiframework.com/doc/guide/2.0/en/concept-behaviors#using-timestamp-behavior) — Sfili_81, Oct 29 '19 at 09:26
@Sfili_81 that page does not state anything about TimestampBehavior **and** validation — Zhigalin - Reinstate CMs, Oct 29 '19 at 10:41

Michal Hynčica · Accepted Answer · 2019-10-29T15:04:59.650

The problem is in order in which the actions are performed.

The creation_time attribute is set by yii\behaviors\TimestampBehavior during the BaseActiveRecord::EVENT_BEFORE_INSERT. This event is invoked by beforeSave() callback.

If you take a look at souce code of insert() method in ActiveRecord you can see the order of actions is:

Validate
Call beforeSave
Do the insert
Call afterSave

So your model is first validated and then the creation_time is set. That's why validation of this attribute is failing.

If your creation_time is only set by TimestampBehavior then there is no need to validate it. If you want to allow editation of this attribute, then you can use scenarios to validate it only during editing.

Yii2, why a model validation fails due to a missing mandatory attribute when that attribute is assigned by a Behavior?

1 Answers1