title: default value for file input form when update image in laravel 5.8
body: <p>I'm Using Laravel 5.8, I'm trying to make update data in laravel, the data is contained images, when the form update did not get a new image, laravel displays an error, that the image is null,
  can I make the old image as the default value for the file input?</p>
  
  <p>this is my controller</p>
  
  <pre><code>public function UploadEdit(Request $request, Books $book,$id_book){
      $book = Books::find($id_book);
      global $old_image;
      $old_image = public_path("img/books/". $book-&gt;image);
      if($request-&gt;hasFile('image')){
          if (File::exists($old_image)) { 
              unlink($old image);
          }
  
          $image = $request-&gt;file('image');
          $image_name = time()."_".$image-&gt;getClientOriginalName();
          $image-&gt;move('img/books',$image_name);
          $book-&gt;image=$image_name;
      }else{
          $book-&gt;image = $old_image;
      }
  
      DB::table('books')-&gt;where('id_book',$request-&gt;id_book,$image_name)-&gt;update([
          'title' =&gt; $request-&gt;title,
          'image' =&gt; $request-&gt;image = $image_name,
          'category' =&gt; $request-&gt;category,
          'description' =&gt; $request-&gt;description
      ]);
  
  
  
      return redirect('/books');
  }
  </code></pre>
  
  <p>this is input file from my form :</p>
  
  <pre><code>&lt;div class="form-group"&gt;
      &lt;label for="image"&gt;Image&lt;/label&gt;
      &lt;input type="file" class="form-control-file" id="image" name="image" id="image" enctype="multipart/form-data" value="{{ asset("img/books/$book-&gt;image") }}"&gt;
      &lt;img src="{{ asset("img/books/$book-&gt;image") }}" width="150"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I'm trying to make the default value  for file form, but still doesn't work</p>