Question

It looks that Model hook beforeDelete don’t work hierarchialy.
Let me explain with example.

class Model_User extends Model_Table{
    public $table='user';
    function init(){
        parent::init();
        $this->debug();
        $this->addField('name');
        $this->hasMany('Item');
        $this->addHook('beforeDelete',$this);
    }
    function beforeDelete($m){
        $m->ref('Item')->deleteAll();
    }
}

class Model_Item extends Model_Table{
    public $table='item';
    function init(){
        parent::init();
        $this->debug();
        $this->addField('name');
        $this->hasOne('User');
        $this->hasMany('Details');
        $this->addHook('beforeDelete',$this);
    }
    function beforeDelete($m){
        $m->ref('Details')->deleteAll();
    }
}

class Model_Details extends Model_Table{
    public $table='details';
    function init(){
        parent::init();
        $this->debug();
        $this->addField('name');
        $this->hasOne('Item');
    }
}

When I call delete() on “grand-parent” Model_User, then it tries to delete all Item records as intended, but from there don’t execute Item.beforeDelete hook and don’t delete Details records before trying to delete Item.

What I’m doing wrong ?

Answer 1

I guess I got it working at least for hierarchial Model structure.

This is how it was done:

class Model_Object extends hierarchy\Model_Hierarchy {
    public $table = 'object';

    function init(){
        parent::init();
        $this->debug(); // for debugging
        $this->addField('name');
        $this->addHook('beforeDelete',$this);
    }

    function beforeDelete($m) {
        // === This is how you can throw exception if there is at least one child record ===
        // if($m->ref('Object')->count()->getOne()) throw $this->exception('Have child records!');

        // === This is how you can delete child records, but use this only if you're sure that there are no child/child records ===
        // $m->ref('Object')->deleteAll();

        // === This is how you can delete all child records including child/child records (hierarcialy) ===
        // Should use loop if we're not sure if there will be child/child records
        // We have to use newInstance, otherwise we travel away from $m and can't "get back to parent" when needed
        $c = $m->newInstance()->load($m->id)->ref('Object');
        // maybe $c = $m->newInstance()->loadBy('parent_id',$m->id); will work too?
        foreach($c as $junk){
            $c->delete();
        }
        return $this;
    }

}

Important things here are:
* extend hierarchy\Model_Hierarchy class not Model_Table
* use appropriate method in beforeDelete hook
* * restrict delete if we have children – throw exception
* * deleteAll – use it when you’re sure that there will be no child/child records
* * newInstance + loop + delete – use it when you have to delete records (even child/child/…) hierarchialy

Maybe some of you have a better solution?