sunshine exercise 5.01

In this exercise we are moving from AsyncTask to AsyncTaskLoader. AsyncTask is not good for resource management when it comes to changing activity states. For example, if the user rotates their screen, then the app is recreated from scratch and all data has to be reloaded. AsyncTaskLoader will cache the state of the activity so in the event of a state change, the data is readily available.

lets get some things out of the way. Our fancy pants app passes in a callback to the initLoader class within the LoadManager.java. My initial understanding from the documentation is that the initLoader is called everytime a state is changed. From what I can tell, the main purpose of this class is to execute the onLoadFinished() once the loader has a) been started b) data is loaded. This allows for

To best understand the workflow of loadmanagers, i found a useful diagram

load manager image

Old Behavior

Use the loadWeatherData() in the main thread.

New Behavior

we are using loaders to break up the tasks using the three loader functions

  1. onStartLoading()
  2. loadInBackground()

  3. deliverResults()

  4. when using AsyncTaskLoader, within the closure, you must implement the AsyncTaskLoader subclass onStartLoading. onStartLoading will load any cached data to avoid duplicating processing.