`Day20` Lesson5 LiveData amp Lifecycle Awareness LiveData ob

Question

`Day20` Lesson5 LiveData amp Lifecycle Awareness LiveData observable data holder class which is lifecycle aware lifecycle awareness LiveData knows about the lifecycle state of its UI controller observers Two way lifecycle observation connection between UI controller amp LiveData nice diagram LiveData will only update UI controllers that are actually on screen If UI controller is off screen it gets no updates When a UI controller goes from off screen back to on screen LiveData will trigger the observer to get the current data immediately When UI controller gets destroyed LiveData internally cleans up its own connection to the observer Backing property amp Encapsulation restricted direct access to the object fields LiveData should be mutable inside the ViewModel but immutable outside the ViewModel MutableLiveData vs LiveData can be read but not modified Backing property allows returning sth from a getter other than the exact object Event vs State `Self Comment` I always get pre lesson quizzes in udacity wrong^^ ex where should ~~ component go to But I won t get intimidated since who cares I m learning haha Plus my memories are amazing amazingly short I remember that I learned this term companion object in the kotlin basics lecture and even remember that it was confusing at that time but I just couldn t recall it exploding head So I got back to my notion memos and remembered what this was So I had some googling time I m using this as summarizing notepad from some point on It somehow seems to ruin this feed so I ll separate this to a comment in my own thread if it bothers any of u joy Was a productive day I should really take care of my mentality keep in mind that if there s a less productive day I ll just have to try harder the next day but just don t get stressed too much `Goals Tomorrow` Finish Lesson5 and start lesson 6 As I view the contents there comes this terminology coroutine Quite thrilling that it is a mystery for me today but not tomorrow Priority Lesson5 gt BLE gt Lesson6 amp Leetcode

JungIn Choi · Answer

Debuggings and etc tips Using Toast amp Logs are important for debugging GuessIt App kept crashing after adding timer functionality viewModel = ViewModelProviders this get GameViewModel class java was the problem At first I did stupid finger princess googling not using my eyes and brains but just copied the error message and checked in stack overflow There was some discussion about ViewModelProviders deprecation issue Following a lecture tutorial based on deprecated library is quite annoying but I m just taking this as debugging practice and stacking my patience After all I should handle all these whenever some library I m using becomes deprecated However though I updated that line using the ViewModelProvider app still crashed So I read the error messages more thoroughly found out that it was throwing a InstantiationException After I looked at my GameViewModel again I figured out that my case was I found out that I put strange constructer maybe some careless auto completion done by option key After I fixed that app didn t crash again Learned how to make commit from a text file Reviewed companion object reading some blog posts Was helpful understanding confusing cases of inheritance learned what shadowing is

Bryan L · Answer

Might help give a better understanding on Companion objects If you get confused about Singleton when he brings it up I d suggest watching it to