php - error yii2 upload Call to a member function saveAs() on null

Question

I am new programmer world and ask for your help guys, I have error "Call to a member function saveAs() on null"

This code in models

[['file'],'file'],

• this code in controllers

              $docfileload = $model->docname;
          $model->file = UploadedFile::getinstance($model,'file');
          $model->file->saveAs('uploads/'.$docfileload.'.'.$model->file->extension);
          $model->save();
  
          //save path in db
          $model->docfile = 'uploads/'.$docfileload.'.'.$model->file->extension;
  

this code in _form

    <?= $form->field($model,'file')->fileinput(); ?>

after I used getInstanceByName like @bluehipy told me I have a new issue look to the pic

enter image description here

Answer 1

UploadedFile::getinstance returns an array of files. Use getInstanceByName or UploadedFile::getinstance($model, 'file')[0].