Gradebook 2.x architecture

This page summarizes some initial ideas and suggestions that may help to resolve Stage 3 of the Gradebook improvements project.

Current issues

These are some of the most important issues with the current Gradebook design that this spec tries to deal with. See http://www.mindmeister.com/89537697/gradebook-2-x-issues-braindump for even more issues.

The grades appear in the gradebook immediately (MDL-25439): The grade values are stateless. We need a way how to store grades in the gradebook but exclude them from aggregations yet. Currently, the hiddenuntil feature tries to solve this but it is pretty limited and hacky (MDL-25440).
Students and teachers may see different values: Because of how grades hiding is implemented currently, it is practically impossible to pre-populate whole grades tree and/or export reliable data (because they are dependent on the current role permissions).
Unable to alter grades processing: There is a demand for alternate methods of grades processing (eg grades over 100% or negative grades) due to local conventions in various countries and school systems.
Grading logic and UI implemented in activity modules: Grading tools like single point grade, scale-based grading or a new rubric-based grading should be handled by the Gradebook core with a rich set of interface toward activity modules (and eventually other plugin types).