arbitrary value to refill the internal subject list

[camallen]

mobile/src/actions/classifier.js

Line 113 in a8ca98f

if (usableSubjects.length < 5) {

Whenever there are 4 or less usable subjects in the internal subject list the app will request new data for the workflow. By default the API will return 10 subjects unless there is a query or internal workflow param to specify the page size.

Some recent API changes (zooniverse/panoptes#3162 support fine grained training data ratios allows a workflow configuration value to specify these page sizes.

The science scribbler team have this set to 4 on their desktop and mobile workflows. Thus upon first submission of a classification the arbitrary value of < 5 is triggered and the mobile app requests new data to add to the list.

This isn't terrible but could be pre-fetching data that a user isn't going to use. Also this can cost bandwidth and quite possibly impact on data quotas and thus cost the user, especially on cell/mobile connections (depending on the cell/mobile plans), https://whatdoesmysitecost.com/test/191024_HA_849feaa6a9f204116495bbe56700f361

Ideally the behaviour here is consistent across our apps and if possible repspects the workflow directive for selector page sizes.
FYI PFE uses < 2
https://github.com/zooniverse/Panoptes-Front-End/blob/bf6eea311431336ae372e1a2361b9d3e1189b4d6/app/pages/project/classify.jsx#L97

Thoughts?