yii2 - dynamicform wbraganca : What's wrong with my code -

after submit request, go blank page. please check code. thanks. i'm using yii2 framework , wbraganca dynamic form plugin.

public function actioncreate()     {         $model = new purchaseorder();         $details = [ new purchaseorderdetail ];          $seq = sequence::findone(['id' => 'po', 'name' => (int)date('ymd')]);         if(is_null($seq)){             $_seq = new sequence();             $_seq->id = 'po';             $_seq->name = (int)date('ymd');             $_seq->value = 0;             $_seq->save();             $model->id = $_seq->id . '/' . $_seq->name . '/' .str_pad($_seq->value+1, 3, "0", str_pad_left);         }         else {             $seq->value += 1;             $model->id = $seq->id . '/' . $seq->name . '/' . str_pad($seq->value, 3, "0", str_pad_left);             $seq->update();         }         $model->trx_date = date('y-m-d');          if ($model->load(yii::$app->request->post())) {             $details = model::createmultiple(purchaseorderdetail::classname());             model::loadmultiple($details, yii::$app->request->post());              //assign po_id             foreach($details $detail){                 $detail->oid = uniqid();                 $detail->po_id = 0;             }              // ajax validation             if(yii::$app->request->isajax){                 yii::$app->response->format = response::format_json;                 return arrayhelper::merge(                     activeform::validatemultiple($details),                     activeform::validate($model)                 );             }              // validate models             $valid1 = $model->validate();             $valid2 = model::validatemultiple($details);             $valid = $valid1 && $valid2;              if($valid){                 $trx = \yii::$app->db->begintransaction();                 try                 {                     // save master record                     if($flag = $model->save(false)){                         // save detail records                         foreach($details $detail){                             $detail->po_id = $model->id;                             if(!($flag = $detail->save(false))){                                 $trx->rollback();                                 break;                             }                         }                                            }                     if($flag){                         //if success commit transaction                         //then view result                         $trx->commit();                         return $this->redirect(['view', 'id' => $model->id]);                     } else {                         return $this->render('create', [                             'model' => $model,                             'details' => $details                         ]);                     }                  }                 catch(exception $ex){                     // transaction failed, rollback                     $trx->rollback();                     throw $ex;                 }             }                                } else {             return $this->render('create', [                 'model' => $model,                 'details' => $details             ]);         }     } 

when click create button, redirect blank page , check log, didn't generate error log. here logs

routing name    value route   'purchase-order/create' action  'app\\controllers\\purchaseordercontroller::actioncreate()' parameters  [] $_get empty.  $_post name    value _csrf   'a0hcehjolxebegy.c15vxd0ydbeilvsvpsq2ouqsdqs0mcothw1qqg==' purchaseorder   [     'id' => 'po/170407/024'     'trx_date' => '2017-04-07'     'supplier_id' => '1'     'remark' => 'test remark'     'total' => '1500000' ] purchaseorderdetail [     0 => [         'item_id' => '1'         'qty' => '10'         'price' => '150000'         'total' => '1500000'         'remark' => 'aa'     ] ] $_files empty.  $_cookie name    value _csrf   'c3c290ca6c2fdb8a905c1692baebc21ba6a5715325855d6e863a91f1cd5cd5c7a:2:{i:0;s:5:\"_csrf\";i:1;s:32:\"pzdfy6b-vz6ipevdvlta6zxz_xhkmeg3\";}' phpsessid   'o1337j64mptbjhptr2o3dcl5k7' request body name    value content type    'application/x-www-form-urlencoded' raw '_csrf=a0hcehjolxebegy.c15vxd0ydbeilvsvpsq2ouqsdqs0mcothw1qqg%3d%3d&purchaseorder%5bid%5d=po%2f170407%2f024&purchaseorder%5btrx_date%5d=2017-04-07&purchaseorder%5bsupplier_id%5d=1&purchaseorder%5bremark%5d=test+remark&purchaseorderdetail%5b0%5d%5bitem_id%5d=1&purchaseorderdetail%5b0%5d%5bqty%5d=10&purchaseorderdetail%5b0%5d%5bprice%5d=150000&purchaseorderdetail%5b0%5d%5btotal%5d=1500000&purchaseorderdetail%5b0%5d%5bremark%5d=aa&purchaseorder%5btotal%5d=1500000' decoded params   [     '_csrf' => 'a0hcehjolxebegy.c15vxd0ydbeilvsvpsq2ouqsdqs0mcothw1qqg=='     'purchaseorder' => [         'id' => 'po/170407/024'         'trx_date' => '2017-04-07'         'supplier_id' => '1'         'remark' => 'test remark'         'total' => '1500000'     ]     'purchaseorderdetail' => [         0 => [             'item_id' => '1'             'qty' => '10'             'price' => '150000'             'total' => '1500000'             'remark' => 'aa'         ]     ] ] 

please help. before

this question resolve skipping validation on foreign key this

[['item_id'], 'exist', 'skiponerror' => true, 'targetclass' => item::classname(), 'targetattribute' => ['item_id' => 'id']],