Problems with Symfony embedded forms -

i trying achieve following scenario:

auction , category entities (many-to-one). category entity has one-to-many relationship categoryattribute entity allows unlimited number of attributes of various types added category. let's cars category have make , year attributes. categoryattribute entity has widgettype property defines how render attribute (input, select etc.), attributevalues data attribute (populating select etc.) , isrequired property tell whether property required or not. far good. managing attributes piece of cake but:

on auction side of things want when user selects given category list render attributes category filled in. translated related auctionattribute entity (many-to-one auction in attributes property in class). auctionattribute has reference categoryattribute, attributevalue hold input or selected value.

well, whole ajax request , fill in of attributes selected category not problem. problem(s) arise when submit form. there 2 issues.

1. how bind attributes part of form actual form validation. let's have car category selected , make attribute required, how validate attribute?

2. how bind attributes input auctionattribute entity in form?

i know embedded forms need hook formevents::pre_submit event not sure how transform attribute entity in there.

in terms of code, have following:

1. when getting attributes category, create auctionattributeformtype , render twig form helper , return html in ajax request:

   $form = $this->createform(new type\auctionattributeformtype(), null, array('csrf_protection' => false));  foreach ($categoryattributes $attribute) {     $form->add('attribute_'.$attribute->getid(), $attribute->getwidgettype(), array('label' => $attribute->getname(), 'required' => $attribute->isrequired()); } 

2. when auction form submitted, hook pre_submit event , when whether there attribute submitted , belongs set of attributes of category far went before got stuck:

   $builder->addeventlistener( form\formevents::pre_submit, function (form\formevent $event) { $auction = $event->getdata();

       if (null !== $auction['category']) {         $categoryattributes = $this             ->repository             ->findattributesforcategory($auction['category'])             ->getresult();          if (count($categoryattributes) > 0) {             $attribute_values = array();             foreach ($categoryattributes $attribute) {                 if (isset($auction['attribute_'.$attribute->getid()])) {                     $attribute_values[$attribute->getid()] = $auction['attribute_'.$attribute->getid()];                 }             }         }     } } 

   );

i need values attribute_values array auctionattribute entities bound auction entity. idea how achieved. think should done through kind of data transformer not sure transform data - should form->add field, or directly touch auction entity filled in data.

any suggestions?

edit:

i made work use of model transformer there problem, when editing record, if there more 1 attribute, first 1 populated data. here sample gist of code:

https://gist.github.com/svetlinstaev/86e066a865478e40718c

my suggestion not convert submitted data via event listeners, use data transformer, attach form field so:

$formbuilder->add(    $formbuilder    ->create('field_name', 'field_type', [       ... field_options ...    ])    ->addmodeltransformer(new somemodeltransformer()) ) 

and "somemodeltransformer" class should this:

class seatingtonumbertransformer implements datatransformerinterface {      /**      * transforms object norm data model data      * norm data field value. have integer field, $normdataobject int.      * in case: need instantiate several new auctionattribute objects , persist them maybe      */     public function transform($normdataobject)     {         $transformedobject = $this->sometransformaction($normdataobject);         return $transformedobject;     }        /**      * reverts transform      * in case: auctionattribute int       */     public function reversetransform($modeldataobject)     {         $transformedobject = $this->someothertransformaction($modeldataobject);         return $transformedobject;     } } 

more info can found here
if need more help, let me know.