title: 'Access-Control-Allow-Origin' issue when API call made from React (Isomorphic app)
body: <p>I'm running into an issue with my isomorphic JavaScript app using React and Express.  </p>
  
  <p>I am trying to make an HTTP request with axios.get when my component mounts</p>
  
  <pre><code>componentDidMount() {
    const url = 'http://ufc-data-api.ufc.com/api/v3/iphone/fighters/title_holders';
    axios.get(url).then( res =&gt; {
      //use res to update current state
    })
  }
  </code></pre>
  
  <p>I am getting a status 200 res from the API, but I am not getting any response data and getting an error in my console</p>
  
  <pre><code>XMLHttpRequest cannot load http://ufc-data-api.ufc.com/api/v3/iphone/fighters/title_holders. 
  No 'Access-Control-Allow-Origin' header is present on the requested resource. 
  Origin 'http://localhost:3000' is therefore not allowed access.
  </code></pre>
  
  <p>However, if I make the request in my server.js</p>
  
  <pre><code>const url = 'http://ufc-data-api.ufc.com/api/v3/iphone/fighters/title_holders';
  axios.get(url).then(res =&gt; {
      //console.log(res);
  });
  </code></pre>
  
  <p>It works fine and I get response data when the server starts. Is this an issue with the actual API or am I doing something wrong? If this was a CORS issue I'm guessing the request in server.js wouldn't work either? Thanks!</p>