two same attributes in POST

Question

I need to upload file with Yii. In view I have row: <?php echo CHtml::activefileField($qualificationModel, 'picture'); ?>, where

$qualificationModel = new SkillsMapping;

Part of controller:

 $skillsModel = SkillsMapping::model();
 $skillsModel->attributes=$_POST['SkillsMapping'];
 $skillsModel->picture=CUploadedFile::getInstance($skillsModel,'picture');
 echo  var_dump($_FILES);
 if($skillsModel->validate())
 {
    if($skillsModel->save())
    {
       $skillsModel->picture->saveAs('images/qual-pics');
       $this->redirect(array('view','id'=>$model->user_id));
    }
 }

When i chose photo and clicked button i have a error Picture cannot be blank. After checking POST request i founded strange thing - request have two attributes - SkillsMapping[picture]= and SkillsMapping[picture]=Lighthouse.jpg. If commented echo in top of this post, both attributes disappear. How to remove empty SkillsMapping[picture] and why it's going? Thanks.

Answer 1

You do not need to remove the empty hidden field because it's there to help you, not hurt you (Yii itself automatically puts it there; see the relevant part of the source).

The hidden field is there so that $_POST is populated with an empty value when no file has been selected to upload. If a file has been selected the file input control will provide its own POST value that overwrites the empty "guard value".