title: How to get the json from API
body: <p>What I want to do is get the json from API and make the buttons from the json content.</p>
  <p>API response doesn't change, so I want to call this just one time.( not need to recall when reloading the widget)</p>
  <p>So, my idea is simply call the API from initState</p>
  <pre><code>  Future&lt;List&gt; getSmartTags() async {
      var url = Uri.parse(&quot;http://localhost:8008/api/smarttags/&quot;);
      var resp = await http.get(url);
      return json.decode(resp.body);
    }
  </code></pre>
  <p>and want to confirm json is correctly returned.</p>
  <pre><code>  void initState() {
      super.initState();
      var temp = getSmartTags();
      print(temp);
    }
  </code></pre>
  <p>This error occurs.</p>
  <pre><code>[VERBOSE-2:ui_dart_state.cc(198)] Unhandled Exception: type '_InternalLinkedHashMap&lt;String, dynamic&gt;' is not a subtype of type 'FutureOr&lt;List&lt;dynamic&gt;&gt;'
  #0      _SmartTagState.getSmartTags (package:flutter_aic/main.dart:64:17)
  </code></pre>
  <p>I think this is the basic concept of <code>Future</code> though, I didn't get it.</p>