fix: Update check-in system to work properly

[ShridharGoel]

Fixes #1672

Checklist:

• I have checked for PMD and check-style issues
• I have read the Contribution & Best practices Guide and my PR follows them.
• My branch is up-to-date with the Upstream development branch.

Changes:

• Proper attendee IDs are being set.
• Attendee check-in status gets updated after scanning.

[iamareebjamal]

Please summarize the changes and explain why it wasn't working and how you fixed it

[ShridharGoel]

The getAttendeesPagewise() method fetches the list at a particular page and appends it to the earlier list which was fetched till then. So, the updateLocal() method wasn't taking the correct list, it was using attendeesList in the presenter which had the list of attendees of just one page and not the complete list. So, I have created getAttendeeList() in AttendeesFragment and replaced attendeeList with getView().getAttendeeList() in AttendeesPresenter.

Apart from this, after scanning, the list was not updating until refreshed. Therefore, I've added this in the ScanQRPresenter:

attendee.isCheckedIn = !attendee.isCheckedIn;
attendeeRepository.scheduleToggle(attendee)
    .subscribe(() -> {
        // Nothing to do
    }, Logger::logError);

[ShridharGoel]

One issue that still exists: The attendee IDs do not update when the fragment is opened for the first time. After refreshing once, the correct values show. This is because the attendees are not getting stored in the local database until refreshed once. Although we are shifting to Room and that would probably fix this, but I think this needs to be fixed right now. So, I'm working on it.
@iamareebjamal Please tell if you have any suggestions on this.

[iamareebjamal]

I'm not able to understand why this part was needed

attendeeRepository.scheduleToggle(attendee)
    .subscribe(() -> {
        // Nothing to do
    }, Logger::logError);

[ShridharGoel]

I'm not able to understand why this part was needed

attendeeRepository.scheduleToggle(attendee)
    .subscribe(() -> {
        // Nothing to do
    }, Logger::logError);

To update the attendee in the local DB?

@NonNull
    public Completable scheduleToggle(Attendee attendee) {
        return repository
            .update(Attendee.class, attendee)
            .concatWith(completableObserver -> {
                AttendeeCheckInWork.scheduleWork();
                if (!repository.isConnected())
                    completableObserver.onError(new Exception("No network present. Added to job queue"));
            })
            .subscribeOn(Schedulers.io());
    }

[ShridharGoel]

attendee.isCheckedIn = !attendee.isCheckedIn;

This is not needed since it is being handled here:

if (toCheckIn) {
            getView().showMessage(
                attendee.isCheckedIn ? R.string.already_checked_in : R.string.now_checked_in,
                true
            );
            attendee.isCheckedIn = true;
        } else if (toCheckOut) {
            getView().showMessage(
                attendee.isCheckedIn ? R.string.now_checked_out : R.string.already_checked_out,
                true
            );
            attendee.isCheckedIn = false;
        }

[iamareebjamal]

But it was working before without it. Why is it needed here, now?

[ShridharGoel]

But it was working before without it. Why is it needed now?

Wasn't working, the attendee status did not change until the list was refreshed.

[iamareebjamal]

Again, before the pagination changes, it was working. You can check in the old APK. It means this was triggered somewhere else as well. Please check the reason why it stopped working

[ShridharGoel]

Okay, checking it.

[ShridharGoel]

Scanning is working as expected. Earlier, I think I was pressing the back button quickly after scanning to go back to the list so maybe that was the reason of the list not showing updated changes or maybe it could have been because of internet connectivity issue. Reverted the changes in ScanQRPresenter.

There was an issue because of which on loading second and further pages, the data of the earlier page was getting deleted from the local DB, due to which attendee IDs started showing as 0 for the earlier pages. Updated the AttendeeRepositoryImpl to fix this.

[ShridharGoel]

One issue that still exists: The attendee IDs do not update when the fragment is opened for the first time. After refreshing once, the correct values show. This is because the attendees are not getting stored in the local database until refreshed once. Although we are shifting to Room and that would probably fix this, but I think this needs to be fixed right now. So, I'm working on it.
@iamareebjamal Please tell if you have any suggestions on this.

This is also fixed.