Uploading files

Handling file uploads is a pretty common task for a web application. Yii has some helpful classes built in to do this. Let's create a simple form that will allow the upload of ZIP archives and store them in /uploads.

Getting ready

1. Create a new application by using the Composer package manager, as described in the official guide at http://www.yiiframework.com/doc-2.0/guide-start-installation.html.

2. Create the @app/web/uploads directory.

How to do it...

1. We will start with the model, so create the @app/models/Upload.php model as follows:

   <?php
   namespace app\models;
   use yii\base\Model;
   use yii\web\UploadedFile;
   class UploadForm extends Model
   {
       /**
       * @var UploadedFile
       */
       public $file;
       public function rules()
       {
           return [
               ['file', 'file', 'skipOnEmpty' => false, 'extensions' => 'zip'],
           ];
       }
       public function upload()
       {
           if ($this->validate()) {
               $this->file->saveAs('uploads/' . $this->file...