title: Building and sorting a new list based on provided list and parameters
body: <p>I have a list of Models:</p>
  
  <pre><code>class Model {
  final DateTime date;
  final String text;
  
  Model({this.date, this.text});
  }
  
  List&lt;Model&gt; _models = [
  Model(date: DateTime(2018, 9, 1), text: 'Text1',),
  Model(date: DateTime(2018, 9, 1), text: 'Text2',),
  Model(date: DateTime(2018, 9, 2), text: 'Text3',),
  Model(date: DateTime(2018, 9, 3), text: 'Text4',),
  Model(date: DateTime(2018, 8, 31), text: 'Text7',),
  Model(date: DateTime(2018, 9, 3), text: 'Text5',),
  Model(date: DateTime(2018, 9, 3), text: 'Text6',),
  ];
  </code></pre>
  
  <p>What I am trying to achieve is to take the date parameter from each model and put all models that match that date into a ListView(). So I can return a list of models for each date. Every time I add data to the list I want it to update &amp; sort by date automatically (no manual stuff). Date formatting is not important here. Question: how can I achieve that?</p>
  
  <p>Here is how I want it to look like:<br>
  <strong>2018/9/3</strong><br>
  Text4<br>
  Text5<br>
  Text6</p>
  
  <p><strong>2018/9/2</strong><br>
  Text3</p>
  
  <p><strong>2018/9/1</strong><br>
  Text1<br>
  Text2  </p>
  
  <p><strong>2018/8/31</strong><br>
  Text7</p>