Hi struggle atm with a form which is implemented on the frontend. I want to save the formdata in an enquiry object which has a many_many relation to my groups object. And in return the groups object has as belongs_many_many relation to the enquiry object. So far so good. Now i create the form for the frontend and run into an issue with the Listboxfield. I cant get it to save the selected groups. How can i do that ??

so my controller looks like that

class EnquiryPage_Controller extends Page_Controller {
function EnquiryForm() {

$groups = DataObject::get("GroupHolder",""); // getting all pages for the groups
$map = $groups->toDropDownMap();

$fields = new FieldSet(
new TextField('Title'),
new TextField('Text'),
new ListboxField('Groups','Groups',$map,$map[0],5,true)
);

// Create actions
$actions = new FieldSet(
new FormAction('doForm', 'Submit')
);

$validator = new RequiredFields('Title', 'Text');

return new Form($this, 'EnquiryForm', $fields, $actions, $validator);
}

function doForm($data, $form) {
$submission = new EnquiryObject();
$form->saveInto($submission);
$submission->write();

Director::redirectBack();
}

}

Would be awesome if someone could help me with my issue.

Because no one was able to help me with my question I figured it out by my self. Took me a while to get my head around it but at the end its logical.

here my new doForm

function doForm($data, $form) {
$submission = new EnquiryObject();

$form->saveInto($submission);

$submission->write();

$data = $form->getData();
foreach($data['Groups'] as $key => $value){
$dob = DataObject::get_one('Group',"ID = ".$value);
$submission->Groups()->add($dob);
unset($dob);
}

Director::redirectBack();
}

thats all you need to do to save many_many relation via a frontend form.

Tee

I also had some problems finding a way of adding many_many relations via the frontend!

But the solution ist actually quite easy, once you find the "Class ComponentSet" http://api.silverstripe.org/default/ComponentSet.html

Here my solution:

class Team extends DataObject {
   static $singular_name = 'Team';
   static $plural_name = 'Teams';
   static $db = array (
      'Title' => 'Varchar(255)',
   );
   static $belongs_many_many = array (
      'Coworkers' => 'Coworker',
   );
}

   function myTeamsForm() {
      $doTeam = DataObject::get("Team");
      $mapTeam = $doTeam ? $mapTeam = $doTeam->toDropdownMap('ID','Title') : array();
      $currentMember = DataObject::get_by_id("Coworker",Member::currentUser()->ID);
      $idList = $currentMember->Teams()->getIdList();
         $fields= new FieldSet(new CheckboxSetField('Teams','meine Teams', $mapTeam, $idList));

      // Create actions
      $actions = new FieldSet(
         new FormAction('doForm', 'Submit')
      );

      return new Form($this, 'myTeamsForm', $fields, $actions);
   }

   function doForm($data, $form) {
      $currentMember = DataObject::get_by_id("Coworker",Member::currentUser()->ID);
      $currentMember->Teams()->setByIDList($data['Teams']);
      Director::redirectBack();
   }

Hope this helps!