Observing property changes with @observable
Learn how to work with Aurelia's observable decorator to create reactive properties inside your component view models that have change callbacks.
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Learn how to work with Aurelia's observable decorator to create reactive properties inside your component view models that have change callbacks.
Last updated
Was this helpful?
Unlike the , the @observable
decorator allows you to decorate properties in a component and optionally call a change callback when the value changes. It works quite similarly to the @bindable
property.
By convention, the change handler is a method whose name is composed of the property_name and the literal value 'Changed'. For example, if you decorate the property color
with @observable
, you have to define a method named colorChanged()
to be the change handler.
This is what a basic observable would look like using conventions:
When the color
value is changed, the colorChanged
callback will be fired. The new changed value will be the first argument, and the existing one will be the second one.
If you prefer, you can also put the @observable
decorator on classes:
If you do not want to use the convention, you can define the callback name for the change handler by setting the callback
property of the @observable
decorator: