Handle cutoff on transmission

[githengi]

When a payload sending fails, the sending app will resend the payload until the receiver acknowledges receipt.

If the connection is reset then the transfer will start from the last known receipt by receiver as defined on this #8

[pld]

Is doing this automatically is required for MVP? Without this the user would have to manually restart the sync, is that correct?

[githengi]

Yes, the user can start the process manually.

Also in the MVP if any cutoff happens then it needs to disconnect and ask user to start afresh to avoid skipping payloads that was not delivered.

[craigappl]

Is this a correct flow?

• Users connect and begin transmission
• Sending App walks out of range and transmission fails
• User interface is presented to both the sender and receiver that the transmission has failed. (We need to define these error states) Both users are instructed to start over again.
• Both users touch a button to close out of the error message
• The sender attempts to connect to the receiver again

Error states:
I assume the Nearby API has clearly defined error states. We need to differentiate between failures in the OpenSRP app during transmission, failures in data quality (i.e. checksum) and failures in the Nearby API due to connection loss.