yii2 load model in controller doesnt load Form's posted data - php

Question

This is my view file and it has one form that should post a file with a text variable data of 0000000005. But for some reason the load function inside the controller does not populate these data.
<?php
use yii\helpers\Html;
use yii\widgets\ActiveForm;
/* #var $this yii\web\View */
/* #var $model backend\models\customs\UploadForm */
/* #var $form ActiveForm */
?>
<div class="vendor_file_upload_form">
<?php $form = ActiveForm::begin(
['id' => 'form-files'],
['options' => ['enctype' => 'multipart/form-data']]
); ?>
<?= $form->field($model, 'AppFile')->fileInput() ?>
<?= $form->field($model,'apid')->textInput(); ?>
<div class="form-group">
<?= Html::submitButton(Yii::t('app', 'Submit'), ['class' => 'btn btn-primary']) ?>
</div>
<?php ActiveForm::end(); ?>
</div><!-- vendor_file_upload_form -->
This is my controller
public function actionFiles($id=null)
{
$model = new UploadForm();
if ($model->load(Yii::$app->request->post()))
{
$model->AppFile = UploadedFile::getInstance($model, 'AppFile');
if ($model->upload())
{
\Yii::$app->getSession()->setFlash('success', 'File has been successfully uploaded.');
return $this->redirect(['index']);
}
else
{
\Yii::$app->getSession()->setFlash('error', 'Wrong File Format , Try proper format.');
return $this->redirect(['index']);
}
}
}
I found that for some reason Load data does not load all the posted form parameters. I have spent 3 hours and I am still unable to understand why my form data is not being transferred properly.
I checked the Payload and I found following which means my data is coming fine but load function is not loading properly.
------WebKitFormBoundaryZfszVA0IZuj02ZFT Content-Disposition: form-data; name="_csrf-backend"
UEZaLmZ4MzEWExBjLz8LSWAnHG9SGgFhaBcqbycRZWc1dGtCAD9JYg==
------WebKitFormBoundaryZfszVA0IZuj02ZFT Content-Disposition: form-data; name="UploadForm[AppFile]"
------WebKitFormBoundaryZfszVA0IZuj02ZFT Content-Disposition: form-data; name="UploadForm[AppFile]"; filename="falcon-wallpaper.jpg"
Content-Type: image/jpeg
------WebKitFormBoundaryZfszVA0IZuj02ZFT Content-Disposition: form-data; name="UploadForm[apid]"
0000000005
------WebKitFormBoundaryZfszVA0IZuj02ZFT--
EDIT:
Below is my model file,
<?php
/**
* Created by PhpStorm.
* Date: 1/8/2017
* Time: 9:52 PM
*/
namespace backend\models\customs;
use backend\models\ApplicationFiles;
use yii\base\Model;
use yii\web\UploadedFile;
/**
* UploadForm is the model behind the upload form.
*/
class UploadForm extends Model
{
/**
* #var UploadedFile
*/
public $AppFile; //files which needs to be uploaded
public $apid; //application_id
/**
* #return array the validation rules.
*/
public function rules()
{
return [
[['apid'], 'required','message'=>'No Application Id found'],
[['AppFile'], 'file', 'skipOnEmpty' => false, 'extensions' => 'png, jpg'],
];
}
public function upload()
{
//upload on the backed/uploads folder with time stamp as the file name
if ($this->validate()) {
$File_name = time() . '.' . $this->AppFile->extension;
if($this->AppFile->saveAs(\Yii::$app->basePath.'/uploads/' .$File_name ))
{
$model = new ApplicationFiles();
$model->name = $File_name;
$model->path = \Yii::$app->basePath.'/uploads/' .$File_name;
$model->application_id = $this->apid;
// $model->type =
$model->save();
}
return true;
}
else
{
return false;
}
}
}
?>