Validate associated models in CakePHP2

Question

I'm a noob in CakePHP and I've been trying to do some complex validations here:

I have the following models: - Fonts (name, file); - Settings(value1,value2,value3,type_id,script_id); - Types(name)

Whenever I create a Font I also create a default setting associated to it. Also, this setting has a type associated. After the Font is created I can associate more settings to it (Font hasMany Settings), but I need to make sure that two settings of the same type are not added to that font. I don't know how to handle this case. Any help is appreciated. Thanks.

score 0 · Accepted Answer · answered Jul 08 '13 at 20:35

I'd use a simple beforeSave validation

//in setting.php model
public function beforeSave($options = array()) {

    if (isset($this->data[$this->alias]['font_id']) && isset($this->data[$this->alias]['type_id']) {
        $otherSettings = $this->find('all', array('conditions'=>
            array('type_id'=>$this->data[$this->alias]['type_id'],
                  'font_id'=>$this->data[$this->alias]['font_id']);

        //check if it's insert or update
        $updated_id = null;
        if ($this->id)
            $updated_id = $this->id;
        if (isset($this->data[$this->alias][$this->primaryKey]))
            $updated_id = $this->data[$this->alias][$this->primaryKey];

        if (count($otherSettings) > 0) {
            if ($updated_id == null)
               return false;  //it's not an update and we found other records, so fail

            foreach ($otherSettings as $similarSetting)
               if ($updated_id != $similarSetting['Setting']['id'])
                  return false;  //found a similar record with other id, fail
        }
    }

    return true; //don't forget this, it won't save otherwise
}

That will prevent inserting new settings to the same font with the same type. Have in mind that this validation will return false if the validation is incorrect, but you have to handle how you want to alert the user of the error. You can throw exceptions from the beforeSave and catch them in the controller to display a flash message to the user. Or you could just not save those settings and let the user figure it out (bad practice).

You could also create a similar function in the model like checkPreviousSettings with a similar logic as the one I wrote above, to check if the settings about to be saved are valid, if not display a message to the user before attempting a save.

The option I prefer is the exception handling error, in that case you'd have to replace the return false with

throw new Exception('Setting of the same type already associated to the font');

and catch it in the controller.

Actually, the better approach is to not even display the settings with the same type and font to the user, so he doesn't even have the option of choosing. But this behind-the-scenes validation would also be needed.

Validate associated models in CakePHP2

1 Answers1