emartynov / flickrdemo Goto Github PK

That was hard exercise!

The solutions:

• Kotlin as development language
• App is separated in two parts - common and feature "Images List"
• Use internal classes as much as possible (for future purposes of the modularisation)
• Use HttpsUrlConnection for simple networking
• Use JSONObject for json parsing
• Use threads pool for background loading, resizing with naive cancellation
• Separate responsibilities in small classes - http, cache, async, use case, view model, view
• Model is observable
• View is around GridView with basic simple adapter
• View model and cache are saved during configuration change in static variables
• Activity and Adapter don't have tests, rest is covered with unit or integration tests
• Use stubs instead of mocking

There are still major issues:

• The names are hard (what is async class doing?)
• Some code is just copy/pasted from internet without deep understanding
• The UI looks choppy - I need to profile app to understand the reason
• The loading image cancellation looks like overlap with new image loading to the reused view - I have to debug to catch the reason
• The image loading starts before view is attached to parent so it causes exception in bitmap resize and you see text placeholder instead of loaded image
• After rotation app still loads some images from internet - I have to debug to find if it is correct (cache is full) or something wrong done with calculation or key
• I decided not to write any have Espresso test for UI acceptance testing
• Some stubs are looking sketchy

The assembled apk is here.

As conclusion - I'm not proud about the written code, unfortunately!