Propel: how to remove link made via many-to-many relation - php

Question

(link to previous question just in case: Struggling with one-to-many relation in an admin form)
I have this many-to-many relation in my Symfony-1.3 / Propel-1.4 project between User and Partner. When the User is being saved, if it has certain boolean flag being true, I want to clear all the links to the partners. Here is what I do at the moment and it doesn't work:
// inside the User model class
public function save(PropelPDO $con = null) {
if ($this->getIsBlaBla()) {
$this->setStringProperty(NULL);
$this->clearUserPartners();
}
parent::save($con);
}
Setting the string property to NULL works; looking at the DB clearly shows it. Thing is however, the USER_PARTNER table still holds the relations between the users and the partners. So I figured I have to clear the links one by one, like this:
foreach($this->getUserPartners() as $user_partner) {
$user_partner->delete();
//UserPartnerPeer::doDelete($user_partner); // tried that too
}
Both don't do the trick.
As I mentioned in my previous question, I am just monkey-learning Symfony via trial and error, so I evidently miss something very obvious. Please point me in the right direction!
EDIT: Here is how I made it work:
Moved the code to the Form class, like so:
public function doSave(PropelPDO $con = null) {
parent::doSave($con);
if ($this->getObject()->getIsSiteOwner()) {
$this->getObject()->setType(NULL);
$this->getObject()->save();
foreach($this->getObject()->getUserPartners() as $user_partner) {
$user_partner->delete();
}
}
return $this->getObject();
}
public function updateObject($values = null) {
$obj = parent::updateObject($values);
if ($obj->getIsSiteOwner()) {
$obj->clearUserPartners();
}
return $this->object;
}
What this does is:
When the boolean flag `is_site_owner` is up, it clear the `type` field and **saves** the object (ashamed I have not figured that out for so long).
Removes all existing UserPartner many-to-many link objects.
Clears newly associated (via the DoubleList) UserPartner relations.
Which is what I need. Thanks to all who participated.

Answer 1

Okey so now you have a many-to-many relation where in database terms is implemented into three tables (User , Parter and UserPartner). Same thing happens on Symfony and Propel, so you need to do something like this on the doSave method that should declare in UserForm:
public function doSave($con = null)
{
parent::doSave($con); //First all that's good and nice from propel
if ($this->getValue('please_errase_my_partners_field'))
{
foreach($this->getObject()->getUserPartners() as $user_partner_relation)
{
$user_partner_relation->delete();
}
}
return $this->getObject();
}
Check the method name "getUserPartners" that should be declared on the BaseUser.class.php (lib/model/om/BaseUser.class.php)

Answer 2

If you are learning Symfony, I suggest you use Doctrine instead of Propel because, I think Doctrine is simplier and more "beautiful" than Propel.
For your problem, I think you are on the good way. If I were you, I will keep my function save() I will write an other function in my model User
public function clearUserPartners(){
// You have to convert this query to Propel query (I'm sorry, but I don't know the right syntax)
"DELETE FROM `USER_PARTNER` WHERE user_id = '$this->id'"
}
With this function, you don't must use a PHP foreach.
But I don't understand what is the attribute StringProperty...

Answer 3

UserPartnerQuery::create()->filterByUser( $userObject )->delete();
or
UserPartnerQuery::create()->filterByUser( $partnerObject )->delete();
Had the same problem. This is a working solution.

Answer 4

The thing is that your second solution, ie. looping over the related objects and calling delete() on them should work. It's the documented way of doing things (see : http://www.symfony-project.org/book/1_0/08-Inside-the-Model-Layer#chapter_08_sub_saving_and_deleting_data).
But instead of bombing the DB with delete queries, you could just as well delete them in one go, by adding a method to your Peer class that performs the deletion using a simple DB query.