ng-book

Architecture 384
With our view variable safely tucked away in the directive, we no longer need to hold onto the view
conditional in our controller. It’s a best practice to keep our controllers thin; using directives allows
us to do so efficiently.
Additionally, isolating our login routes inside of a directive, as above, also makes it very easy to test
their functionality.
Sharing Data between Controllers
In Angular, we can share data between two controllers in a few different ways. We can nest our
controllers underneath the same parent controller and allow each controller to independently modify
the values of the parent controller’s $scope attribute, or we can share a value inside of a service.
It’s preferable to hold onto data inside of a service, but the more efficient method can depend upon
the situation. For instance, inside of a dialog box, it makes sense for us to hold onto the data that the
dialog box is showing inside of a parent controller.
Directives
Knowing when to write a directive is as important as to knowing when not to write one. More often
than not, it’s generally a good idea to write a directive.
It’s always better to err on the side of using directives over not using directives. As we’ve seen above,
they reduce the amount of clutter inside of our controller.
It’s also much simpler to test directives than to test controllers.
Directives do not always need to have a view template. Oftentimes, they can simply serve as a shim
to handle dealing with data underneath the view. The ngModelController is an example of when
this functionality comes in handy.
Testing
We always encourage testing inside of our apps. We constantly strive to write unit tests for any
piece of functionality that has any level of complexity. These tests allow us to feel confident about
our code, no matter how small. Focusing on unit tests also enables us to be efficient with time and
to focus on functionality.
Once we’re confident we have tested the API of our Angular apps with unit tests, we can start to
write end-to-end tests. End-to-end tests can be brittle and dependent upon the view, so we usually