title: Angular 2 two-way binding propagation through components
body: <p>I'm trying to make two-way binding in a component and propagate it through other components that contain the child component:</p>
  
  <p>I have a child component, with two-way binding and it's working. The binding is pointing to a variable called <code>child_value</code></p>
  
  <p>Then this child component is present in the template of a parent component. I want a two-way binding here too, so I use <code>[(child_value)]=parent_value</code></p>
  
  <p>Finally this parent component is used in my application, so in this component I also want a two-way binding like <code>[(parent_value)]=application_value</code></p>
  
  <p>But only the first binding is working in two way. To exemplify it I created this plunker</p>
  
  <p><a href="http://plnkr.co/edit/IWVzmRbqL3ARFaYxjs3F?p=preview" rel="nofollow">http://plnkr.co/edit/IWVzmRbqL3ARFaYxjs3F?p=preview</a></p>
  
  <p>When you drag the slider you can see that the Child value updates, but the others don't. If I change the <code>application_value</code> in code, through the button, then it is propagated through all components. </p>