Context
To improve the Open edX mobile experience, we need to provide learners with a fast, accurate list of upcoming exam and assignment due dates across all of their enrolled courses. This is critical for enabling mobile-first learning workflows, proactive planning, and push notifications.
The current approach, which relies on get_course_date_blocks() and modulestore traversal, is inefficient, especially for multi-course scenarios. The Open edX community has committed to limiting modulestore usage in runtime systems (ADR 0011) and modularizing content and date management.
Decision Summary
We suggest reusing and extending the edx-when application as the unified backend for both course-level and user-level due dates:
- Use
CourseDateto store published due dates from course metadata - Use
UserDateto store user-specific overrides, including:- Personalized schedules (self-paced)
- Instructor-granted extensions
- Create a new API endpoint to return a merged and filtered list of upcoming due dates for the authenticated user
Architecture Overview
What We Reuse
| Component | Role |
|---|---|
edx-when.CourseDate |
Stores canonical due dates published for each course |
edx-when.UserDate |
Stores per-user overrides (e.g., extensions, personalized pacing) |
Schedules |
Provides start_date for self-paced learners (used in overrides) |
What We Add
| Component | Purpose |
|---|---|
| New API | Returns all due dates visible to the user across their courses |
| Runtime logic | Merges CourseDate and UserDate, applies filtering/visibility |
Benefits
- Performance: Indexed queries instead of runtime block traversal
- Consistency: All dates managed in one canonical system
- Maintainability: No need to create redundant data models
- Scalability: Reusable for LMS, mobile, and analytics
- Forward-compatible: Aligned with plans to remove MongoDB and improve RBAC
Scope Limitations
CCX courses (Custom Courses for EdX) are excluded from this implementation due to their unique override structure and management.