AngularJS: Maintaining Web Applications

Lesson 4: Dependency Injection and Services

Cohesion is one of the most important and perhaps overlooked concepts of the object-oriented programming paradigm. It refers to the responsibility of each part of the software. No matter which component we talk about, every time it implements behavior different from its responsibilities, cohesion is degraded.

Low cohesion applications contain plenty of duplicated code and are hard to unit test because it is difficult to isolate the behavior, which is usually hidden inside the component. It also reduces the reuse opportunities, demanding much more effort to implement the same thing several times. In the long term, the productivity decreases while the maintenance costs are raised.

With AngularJS, we are ...