How do I include record relationships in validation?

Question

Say I have a record defining a foreign key relationship which is set to required, such as:

public function defineRelations()
{
    return [
        'type' => [
            static::BELONGS_TO,
            'Events_EventTypeRecord',
            'required' => true,
            'onDelete' => static::CASCADE
        ]
    ];
}

If I try to save the record with typeId not set I'll eventually get a database exception but the error won't show up if I call $record->validate().

How do I make a relationship fail validation?

Answer 1

Yii/Active Record won't do this by default. You'd need to manually add an exists validation rule to the typeId attribute to get it to behave like you're looking for.

Answer 2

Thanks to Brad for pointing me in the right direction.

I added this rules method to my record.

public function rules()
{
   $rules = parent::rules();

   $rules[] = [
       'typeId',
       'exist',
       'allowEmpty' => false,
       'attributeName' => 'id',
       'className' => 'Craft\Events_EventTypeRecord',
       'message' => 'You must enter a valid type'
   ];

   return $rules;
}

exist is a shortcut to Yii's built-in CExistValidator validator. The other key => value pairs are properties of that built-in validator.

You could also do it as a separate validator class. Something like:

<?php namespace Craft;

use CExistValidator;

class Events_EventTypeExistValidator extends CExistValidator
{

    public function validateAttribute($object,$attribute)
    {
        $this->message = "You must enter a type";
        $this->allowEmpty = false;
        $this->attributeName = 'id';
        $this->className = 'Craft\Events_EventTypeRecord';

        parent::validateAttribute($object,$attribute);
    }
}

If you did it this way your record's rules method would include:

public function rules()
{
   $rules = parent::rules();

   $rules[] = ['typeId', 'Craft\Events_EventTypeExistValidator'];

   return $rules;
}