Issues faced while uploading images as part of the QuestionnaireResponse in low Bandwidth setting

[joiskash]

Is your feature request related to a problem? Please describe.

• HAPI does not support multipart upload
• Base64 increases image size by 30% . This results in transaction bundles becoming too big around 15MB with 2 images.
• Client times out . We have taken the approach of saving the image as a file and handling upload separately. We are planning to use this library https://tus.io/

Describe the solution you'd like Change the getQuestionnaireResponse API to return the QuestionnaireResponse and Binary blobs / file URIs for large Media resources captured as part of data capture.

Describe alternatives you've considered We are currently extracting the Base64 String from the QuestionnaireResponse and saving it to file.

Additional context This is also related to point 2 in issue https://github.com/google/android-fhir/issues/1483

Would you like to work on the issue? Please state if this issue should be assigned to you or who you think could help to solve this issue.

[AdityaKBhadragond14]

So, the current issue is that if we want to get the base64 data from the questionnaire response we have to know the "linkId" for the item with the base64 data and iterate to it and then get the data.

To eliminate this iteration of finding the item with the "linkId" for the base64 data we can think of the following two solutions:

1. change the getQuestionnaireResponse API to return the QuestionnaireResponse and the blob.
2. save the base64 data to a file and return the file uri with the getQuestionnaireResponse API call.

But there can be one issue with the second approach is that the getQuestionnaireResponse API call will return a fixed uri which cannot be customized and it might limit the application to use the fixed uri and not modify it according to its use.

[joiskash]

@FikriMilano @omarismail94 @jingtang10 do you have any opinion on what approach is better or worse?

[FikriMilano]

This was discussed before w @jingtang10 and @aditya-07, can you check this ticket? https://github.com/google/android-fhir/issues/1858