Question

I’ve got a Application with 4 activities, A, X, Y, and Z.

A is a kind of landing Activity, which displays a bunch of information from a database for the user.

X, Y, and Z are Activities started by A to modify the data. These activities do not actually query the database, but rather return the changed information to A, which does all the work in onActivityResult. The flow is always A -> X or Y or Z -> A. This works perfectly.

What I’d like to do is make it so that the user can navigate between X, Y, and Z any number of times until a save button is clicked. This would modify the flow such that A -> X -> Y -> Z -> A is possible. However, the data only needs to be persisted from the Activity that clicks save, in that example Z. A would then receive the result from Z, handle this change, and continue. If the user navigates in this way, it doesn’t matter what happened in X and Y, they have been discarded.

I’ve made a few attempts at this. My best was by calling finish() immediately after X, Y, or Z starts another activity that’s not A. This allows the user to return to A when clicking save, meaning the navigation aspect of it is correct, but the result code that gets sent is always RESULT_CANCELED. I’ve looked into using the Intent flag FLAG_FORWARD_RESULT, but I don’t have experience with it and it throws an error when used with an activity that was already started for result. I’m not sure that’s even the right technique to be exploring, because from what I’ve read its only used if there will be one activity in between the calling activity and the one that returns the result.

Is such a flow even possible? Basically, I need an Activity to launch another for result, allow the user to perform some arbitrary amount of navigation from that second activity, then return a result to the original activity when they’re done navigating. Its possible to just modify the code such that X, Y, and Z do the database access themselves, but I would rather avoid it if I could.

Answer 1

However, the data only needs to be persisted from the Activity that clicks save,

It seems to me the simplest thing would be not to use startActivityForResult(...) in Activity A and just use startActivity(...) followed by finish() to terminate Activity A.

Then, when any of the other Activities have their Save button clicked get them to call startActivity(...) for Activity A and pass the data which needs to be saved as Intent extras.

You then just need to use getIntent() in the onCreate(...) method of Activity A to get what is effectively the ‘result’. If the Intent is null or doesn’t contain expected data to be persisted, then this is a ‘first-launch’ scenario but if the data is there, you’ll know Activity A was started as a result of a Save operation in one of the other Activities.