title: Store HTML datalist options in another file without using Javascript
body: <p>In <code>index.html</code> there is a datalist in a <code>&lt;form&gt;</code> that looks like:</p>
  
  <pre><code>&lt;input id="my_input" type="email" list="my_list" multiple&gt;
  &lt;datalist id="my_list"&gt;
          &lt;option value="Number 1"&gt;
          &lt;option value="Number 2"&gt;
          &lt;option value="Number ..."&gt;
          &lt;option value="Number N-1"&gt;
          &lt;option value="Number N"&gt;
  &lt;/datalist&gt;
  &lt;input type="submit"&gt; &lt;!-- Leaving out the form code for this MWE. --&gt;
  </code></pre>
  
  <p>It is desirable for the (large number of) <code>option</code> items to be pulled out of the main HTML file and into some external file, without having to use Javascript to dynamically create the datalist.</p>
  
  <p>Pseudo code demonstrating what is wanted:</p>
  
  <pre><code># data.html
  &lt;datalist id="my_list"&gt;
          &lt;option value="Number 1"&gt;
          &lt;option value="Number 2"&gt;
          &lt;option value="Number ..."&gt;
          &lt;option value="Number N-1"&gt;
          &lt;option value="Number N"&gt;
  &lt;/datalist&gt;
  </code></pre>
  
  <p>and</p>
  
  <pre><code># index.html
  &lt;input id="my_input" type="email" source="data.html" list="my_list" multiple&gt;
  &lt;input type="submit"&gt;
  </code></pre>
  
  <p>The solution doesn't have to be broken out exactly like above, as long as:</p>
  
  <ol>
  <li>The (large number of) <code>option</code> values are in a separate file.</li>
  <li>A form in <code>index.html</code> is able to get the selected datalist items to submit.</li>
  <li>Javascript isn't needed to construct the datalist in <code>index.html</code>.</li>
  </ol>
  
  <p>The first thing I tried was HTML imports, but it turns out <a href="https://developer.mozilla.org/en-US/docs/Web/Web_Components/HTML_Imports" rel="nofollow noreferrer">they're deprecated</a>, so I didn't pursue it very far.  Then I sunk a bunch of time into trying to do this with <a href="https://stackoverflow.com/a/28754598/1717828">the object tag</a>, but it seems Javascript is necessary to get the values.</p>
  
  <p>Is there a way to do this in HTML?</p>