title: Rails, is there a way to give a file_field an image by default?
body: <p>I have an edit form for my articles.</p>
  
  <p>Every article has an image.</p>
  
  <p>I have Current Image and Change Image sections.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>&lt;%=form_for @article, url: articles_update_path,remote: true, html: {class: "form-horizontal"} do |f|%&gt;
  
  &lt;fieldset class="content-group"&gt;
    &lt;legend class="text-bold"&gt;Images&lt;/legend&gt;
    &lt;div class="form-group"&gt;
      &lt;label class="col-lg-2 text-semibold"&gt;Current image:&lt;/label&gt;
      &lt;div class="col-lg-10"&gt;
        &lt;%= image_tag @article.image_url(:thumb) unless @article.image.blank?%&gt;
      &lt;/div&gt;
    &lt;/div&gt;
    &lt;div class="form-group"&gt;
      &lt;label class="col-lg-2 text-semibold"&gt;Change image:&lt;/label&gt;
      &lt;div class="col-lg-10"&gt;
        &lt;%= f.file_field :image, :class =&gt; 'file-input-custom', 'data-show-caption' =&gt; true, 'data-show-upload' =&gt; false, :accept =&gt; 'image/*'%&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/fieldset&gt;
  
  &lt;% end %&gt;
  </code></pre>
  
  <p>Now the thing is that if the user chooses to edit the article and does not give an image again, there is no image. </p>
  
  <p>I want to make my edit form so that if someone does not pick an image, the image that the article already has is saved.</p>
  
  <p>Is that possible?</p>