title: Aurelia binding, bind a function to a property of an object without using propertyObserver
body: <p>So usually, when I want to subscribe to a variable, I would just declare the variable and declare a function with the variable name followed by the word 'Changed' at the end of the function such as below:</p>
  
  <pre><code>test = '';
  
  testChanged() {
  // do stuff here
  }
  </code></pre>
  
  <p>Aurelia provides a very nice way of handling this. However, what do I do if I want to subscribe to a property that is inside an object without using the <code>bindingEngine.propertyObserver</code></p>
  
  <p>For example:</p>
  
  <pre><code>model = {
    a: '',
    b: ''
  }
  </code></pre>
  
  <p>How do I subscribe to <code>model.a</code> using the same convention as above?</p>