title: Using HttpModule (deprecated) with Angular 9
body: <p>I recently updated from Angular 4 to 9. I did the following:</p>
  <ol>
  <li>Created new Angular 9 project, copied all code into angular 9 project</li>
  <li>Updated <code>rxjs</code> (added pipes where necessary, removed concat)</li>
  <li>Fixed easy to fix warnings (unused modules variables etc)</li>
  <li>Installed <code>HttpModule</code> (deprecated) to eliminate errors relating to 'cannot find HTTP' errors and get my project back on track</li>
  </ol>
  <p>I am now at the point where running <code>ng build / ng serve</code> does not throw any errors, and I am able to visit local host and get my landing page. However, using my old login form does not work. I keep getting a <code>CORS</code> error, though I have the following headers set in <code>express</code>:</p>
  <pre><code>app.use(function(req, res, next) {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, PATCH, DELETE, OPTIONS');
    next();
  });
  </code></pre>
  <p><code>Relevant Package Details: &quot;@angular/core&quot;: &quot;~9.1.4&quot; &lt;-- all angular components are at this point, &quot;@angular/common&quot;: &quot;~9.1.4&quot;, &quot;@angular/http&quot;: &quot;^7.2.16&quot;, &quot;express&quot;: &quot;^4.17.1&quot;</code></p>
  <p>My questions are:</p>
  <ol>
  <li>Is it possible to run an angular 9 app with the <code>HTTP module</code> as I am trying to do?  If anyone has had success with it, were there any configuration changes / was it plug and play?</li>
  <li>Is it possible the CORS error could be related to using <code>HTTP module</code> rather than updating to httpClient?</li>
  <li>If I have to update to <code>httpClientModule</code>, is there a tool/utility that can be used to make this update easier?</li>
  </ol>