title: form_for params
body: <p>I need to submit a form to an external URL, so I have this:</p>
  
  <pre><code>form_for(@task, :url =&gt; "https://www.external.com/Submit") do |f|)
      &lt;%= f.hidden_field :assignmentId, :value =&gt; @assignment %&gt;
      &lt;%= link_to image_tag(@imagelocation) %&gt;
  ....
  </code></pre>
  
  <p>I am using <code>form_for</code>, because I need to access to my controller variables.</p>
  
  <p>The external server looks for a param, <code>assignmentId</code>. When the form is submitted, the param is actually available as</p>
  
  <pre><code>params[:task][:assignmentId]
  </code></pre>
  
  <p>which fails to pass validation on the external server.</p>
  
  <p>How do I resolve this? How do I access variables from my controller and pass 'naked' params to the external server?</p>
  
  <p>[edit] Here's what the submit params looks like</p>
  
  <blockquote>
    <p>utf8=%E2%9C%93&amp;_method=put&amp;task%5BassignmentId%5D=2LVQ39Z0B6UWI8NXYWJTYRKGQXIMXN&amp;task%5Boutput%5D=carpet&amp;commit=Post</p>
  </blockquote>
  
  <p>I want it to not have the task referenced.</p>