title: Google Form, make answer field readonly
body: <p>I'd like to make one of the answer field in the Google form read-only or hidden so that the form recipient won't be able to modify it/ see it .</p>
  
  <p>Is that possible?</p>
  
  <p><strong>here is the context</strong>:</p>
  
  <p>So basically my ultimate goal is to leverage <a href="https://www.google.com/forms/about/" rel="noreferrer">Google Forms</a> functionality to send surveys to recipients and track theirs answers in a <a href="https://support.google.com/docs/answer/2917686?hl=en" rel="noreferrer">response spreadsheet</a>. </p>
  
  <p>So far so good...</p>
  
  <p>Now let me introduce you to 2 constraints imposed on me:</p>
  
  <ol>
  <li><p>Forms sent to recipients need to have some information about the recipient already pre-filled.</p></li>
  <li><p>The Url provided to each recipient for accessing the form is used to submit and later to update the answers provided on the form.</p></li>
  </ol>
  
  <p>See the second constraint is tricky...The common thing to do is generate a <a href="https://support.google.com/docs/answer/160000?hl=en" rel="noreferrer">pre-filled Url</a> send that to the recipient and once they've answered the form you can have a confirmation page where you provide them with a <a href="https://developers.google.com/apps-script/reference/forms/form-response" rel="noreferrer">Edit Url</a> that they can use to then update their answers (with last updated answered already pre-filled).</p>
  
  <p>In my case, I cannot provide them with a second url (the Edit Url). It's a one-time thing: I provide one url for each recipient and they'll have to be able to use that same url to answer and update the question-- at a later time if they need.</p>
  
  <p>This functionality isn't supported by Google so I had to write a script that reads from a spreadsheet, use the data in each row to pre-filled a designated form, submit each form then generate an Edit Url for each recipient which I then insert in the "edit url" column of my spreadsheet. I can now give the urls to the recipients and they'll be able to use that url over and over again to update their answers in the survey.</p>
  
  <p>Now to come back to the hidden/readonly field. In my spreadsheet, I have a unique alphanumerical value for each recipient. I want that to be passed to the form so that when they answer (answers are recorded in a response spreadsheet) I'll be able to identify each recipient by this unique "id".</p>
  
  <p>I've written a lot here but I know it's important to give context to people so that they we can all help each other out in a precise and thoughtful way.</p>