title: How to view image and pdf files preview in yii2 kartik multiple file upload in update form
body: <p>Here below is the kartik file input widget in update_form.</p>
  
  <pre><code>echo FileInput::widget(
      [
          'name' =&gt; 'BriefRequirements[requirement_value][]',
          'attribute' =&gt; 'assets_file',
          'id' =&gt; 'assets_file',
          'options' =&gt; ['multiple' =&gt; true],
          'pluginOptions' =&gt; [
              'overwriteInitial' =&gt; false,
              'initialPreview' =&gt; $image_url,
              'deleteUrl' =&gt; ' site/delete',
              'initialPreviewAsData' =&gt; true,
              'initialPreviewFileType' =&gt; 'image' //'pdf'
          ]
      ]
  );
  </code></pre>
  
  <p>below is multiple image loading code,</p>
  
  <pre><code>foreach ($modelRequirements as $req) {
      $image_url[] = Yii::$app-&gt;request-&gt;baseUrl
          . '/theme/business_campaign_files/'
          . $req['requirement_value'];
  }
  </code></pre>
  
  <p>I need help with my two questions:</p>
  
  <ol>
  <li><p>Need to show all selected format files like image, pdf, doc etc [I tried to like <code>'initialPreviewFileType'=&gt;'any'</code>] not working.</p></li>
  <li><p>I want to pass the selected image id to action to delete the image? - <code>'deleteUrl' =&gt; ' site/delete'</code>,<code>'id'=&gt;12</code>, &lt;-- like this.</p></li>
  </ol>