Magento 2 model fields validation?

Question

Where is the correct place to validate field in model?

For example, I have a database, with a table Product, but the database designer didn't force NOT NULL in some required fields (for instance, column SKU). So now I have to check whether these fields are NULL or not by code

I thought it will be added in setData() method. But I think setData() should only care about the "set data" job. Is there any better place for this validation job?

Answer 1

As far as I know, our model usually derives from \Magento\Framework\Model\AbstractModel class. So, we can validate the data before saving it by using Observer or overload beforeSave method in our Model.

Answer 2

After a couple of hours googling, I found this article https://www.ashsmith.io/magento2/module-from-scratch-module-part-2-models/

Model is used to interact with data Resource model is used to interact with database (CRUD for example)

So I think the best place to check data validation is in Resource model.

In Resource model, there is a method called _beforeSave

    /**
     * Process post data before saving
     *
     * @param \Magento\Framework\Model\AbstractModel $object
     * @return $this
     * @throws \Magento\Framework\Exception\LocalizedException
     */
    protected function _beforeSave(\Magento\Framework\Model\AbstractModel $object)
    {
    }

Override this function to validate data.

Answer 3

Looking at the code of save method in Magento\Framework\Model\ResourceModel\Db, I can see that there is validateBeforeSave method which is being called on model object, so you can override _getValidationRulesBeforeSave method in your model where you can provide set of validation rules to validate your model.

Additionally, if validation fails then you can use _dataSaveAllowed flag to stop the saving operation.

Refer Magento\User\Model\User.php for reference.

I hope this helps someone looking for model data validation.