php - Assign and update entity property in Symfony2 form -

is there anyway can assign entity , edit 1 of it's properties in single symfony2 form?

example:

tasks have many activities.

when create activity assign task through entity form field. want update task remainingestimateinseconds when entity created.

activity entity:

<?php  namespace appbundle\entity;  /**  * activity  *  * @orm\table()  * @orm\entity(repositoryclass="appbundle\entity\activityrepository")  */ class activity {      /**      * @orm\column(name="id", type="integer")      * @orm\id      * @orm\generatedvalue(strategy="auto")      */     private $id;      /**      * @assert\notnull()      * @orm\manytoone(targetentity="task")      */     private $task; } 

task entity:

<?php  namespace appbundle\entity;  use doctrine\orm\mapping orm;  /**  * task  *  * @orm\table()  * @orm\entity(repositoryclass="appbundle\entity\taskrepository")  */ class task {     /**      * @var integer      *      * @orm\column(name="id", type="integer")      * @orm\id      * @orm\generatedvalue(strategy="auto")      */     private $id;      /**      * @assert\notblank()      * @orm\column(name="title", type="string", length=255)      */     private $title;      /**      * @orm\column(name="remainingestimateinseconds", type="integer", length=255, nullable=true)      */     private $remainingestimateinseconds; } 

activity form:

my current implementation using non-mapped field. remaining estimate set onto task in controller isn't best implementation.

<?php  namespace appbundle\form;  use symfony\component\form\abstracttype; use symfony\component\form\formbuilderinterface; use symfony\component\optionsresolver\optionsresolver; use symfony\component\validator\constraints\notnull;  class activitytype extends abstracttype {     /**      * @param formbuilderinterface $builder      * @param array $options      */     public function buildform(formbuilderinterface $builder, array $options)     {         $builder->add('description');         $builder->add('task');         $builder->add('remainingestimateinseconds', 'integer', array(             'mapped' => false,             'constraints' => array(                 new notnull()             )         ));     }      /**      * @param optionsresolver $resolver      */     public function configureoptions(optionsresolver $resolver)     {         $resolver->setdefaults(             array(                 'data_class' => 'appbundle\entity\activity',             )         );     }      /**      * @return string      */     public function getname()     {         return 'activity';     } } 

i tried using property_path => "task.remainingestimateinseconds" duplicate property_path throwing kind of error.

what using non-mapped field post_set_data , post_submit listeners on main form prepopulate field/update object?