Can't upload files reliably in Yii2 - yii2

Question

I got this method that's intended to upload a file, but sometimes it does so when $this->imageFile is not instantiated. I have no idea why.
public function upload()
{
$path = Url::to('#webroot/images/photos/');
$filename = strtolower($this->username) . '.jpg';
$this->imageFile->saveAs($path . $filename);
return true;
}
I call the method upload() in beforeSave() like this:
public function beforeSave($insert)
{
if(parent::beforeSave($insert)){
if($this->isNewRecord)
{
$this->password = Yii::$app->security->generatePasswordHash($this->password);
}
$this->upload();
return true;
}
else
{
return false;
}
}
I called this method like 100 times with mixed results. I have no idea why this method call doesn't give the same result. It should either never work or always work, but for some reason the code is not deterministic at all.
public function actionCreate()
{
$model = new Member();
$model->imageFile = UploadedFile::getInstance($model, 'imageFile');
if ($model->load(Yii::$app->request->post()) && $model->save()) {
return $this->redirect(['view', 'id' => $model->id]);
} else {
return $this->render('create', [
'model' => $model,
]);
}
}
Another thing, when I use this code, I get a file, but the username is blank so I get a .jpeg file without a name.
public function actionCreate()
{
$model = new Member();
$model->imageFile = UploadedFile::getInstance($model, 'imageFile');
$model->upload();
if ($model->load(Yii::$app->request->post()) && $model->save()) {
return $this->redirect(['view', 'id' => $model->id]);
} else {
return $this->render('create', [
'model' => $model,
]);
}
}

Answer 1

<?php
if ($model->load(Yii::$app->request->post()) && $model->save()) {
return $this->redirect(['view', 'id' => $model->id]);
} else {
return $this->render('create', [
'model' => $model,
]);
}
In the If clause you are redirecting to view and $model disappears between requests naturally. But in else you sending $model to view directly. It looks like the buggy section.
The other one, when you move the $model->upload() to actionCreate, you are placing it before If statement but you are loading the post to the model in if clause so, naturally user wasn't loading when you are trying to upload.
If you are prefer to send $model->upload() to action just be sure to call following method before upload. $model->load(Yii::$app->request->post())