How to create new extention in Yii2 Framework?

1. Create Extension in yii2.
> in short : go to @app/vendor/yourname

2. create Your Extension Directory : mk-zip/zip/ create file name
FileZip.php
<?php
namespace zip\file;
use Yii;
use yii\helpers\ArrayHelper;
use yii\helpers\Html;
use kartik\base\InputWidget;
use kartik\base\TranslationTrait;
use yii\web\UploadedFile;

class FileZip extends InputWidget
{   
    public function init()
    {
        parent::init();
    }
    public function uploadZip() {
        return 'Mahehs Kathiruya';
    }     
    public function upload($model)
    {
        if ($model->validate()) {
            $model->imageFile->saveAs('uploads/' . $model->imageFile->baseName . '.' . $model->imageFile->extension);
            return true;
        } else {
            return false;
        }
    }
}
?>

3. create composer.json
{
    "name": "mk-zip/",
    "description": "An enhanced FileInput widget for Bootstrap 3.x with file preview, multiple selection, and more features (sub repo split from yii2-widgets)",
    "keywords": ["yii2", "extension", "widget", "input", "file", "form", "upload", "jquery", "plugin"],
    "homepage": "",
    "type": "yii2-extension",
    "license": "BSD-3-Clause",
    "authors": [
        {
            "name": "Mahesh Kathiriya",
            "email": "phpmk888@gmail.com",
            "homepage": ""
        }
    ],   
    "autoload": {
        "psr-4": {
            "zip\\file\\": ""
        }
    },
    "extra": {
        "branch-alias": {
            "dev-master": "1.0.x-dev"
        }
    }
}

4. Go to Main Composer.json file open add "mk-zip/zip":"*" in Require

5. go to yiisoft open extentions.php add
'mk-zip/zip' =>
    array(
        'name' => 'mk-zip/zip',
        'version' => '9999999-dev',
        'alias' =>
        array(
            '@zip/file' => $vendorDir . '/mk-zip/zip',
        ),
    ),
   
6. call zip extention in front end
use zip\file\FileZip;
FileZip::uploadZip();