Why is onAttach called before onCreate?

Question

In a Fragment\'s Lifecycle, the onAttach() method is called before the onCreate() method. I can\'t wrap my head around this. Why would you attach a Fragment first?

Answer 1

Two Points from Android developer Site hints at why onAttach() is called before onCreate() in case of Fragment Life cycle.

1. A fragment must always be embedded in an activity. Now this means for Fragment to EXIST, there has to be a "living" Activity.
   Also, When you add a fragment as a part of your activity layout, it lives in a ViewGroup inside the activity's view hierarchy.

So Fragment must FIRST "attach" itself to activity to defines its own view layout

2. onCreateis Called to do initial creation of a fragment.

It is obvious that you will create something only when its pre-condition of creation is in place (and the pre-condition is A fragment must always be embedded in an activity, and it must be attached to its Activity)