title: How to execute a specific function if a field is modified in Odoo 8?
body: <p>I am working with the <code>product.product</code> object. It has a field named <code>qty_available</code>, which indicates the available quantity of the product in stock, as its name says.</p>
  
  <p>Normally, I would add an <code>@api.depends('qty_available')</code> decorator to the method I want to be executed. But I think this method will not be executed unless I create a computed field which calls it. The problem is that the field <code>qty_available</code> can be modified from a lot of different views, and it would be very uncomfortable to modify each of those views to add the computed field.</p>
  
  <p>Is there any way to do this rightly?</p>