Manage submissions speed

[dwang3851]

Description

This changes implements server-side pagination for the manage submissions page to improve loading times.

Motivation and Context

Previously, it would take about 1.5 seconds for each page of the manage submissions page to load since we would render all of them at once. For example, for a submissions page with 400 submissions, it would take about 6 seconds. This change renders only one page at a time, to take a maximum of 1.5 seconds each time.

How Has This Been Tested?

Tested all of the manage submissions functions locally

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have run rubocop and erblint for style check. If you haven't, run overcommit --install && overcommit --sign to use pre-commit hook for linting
• [ ] My change requires a change to the documentation, which is located at Autolab Docs
• [ ] I have updated the documentation accordingly, included in this PR

[coderabbitai[bot]]

📝 Walkthrough

Walkthrough

Switched the submissions index to DataTables server-side rendering. Controller now serves paginated/searchable/sortable JSON and a new row formatter. Client JS manages selection state, delegated events, dynamic row rendering, and batch-action enablement. View removed server-rendered rows and provides header + select-all UI.

Changes

Cohort / File(s)	Summary
Server-side DataTables & Controller app/controllers/submissions_controller.rb	Added JSON handling for DataTables (paging, search by email, multi-column sort including computed score), computes recordsTotal/recordsFiltered, and introduced format_submission_for_datatable(submission, score = nil); declared action_auth_level for new action; removed prior per-request caching logic.
Client DataTables Initialization & Selection State app/assets/javascripts/manage_submissions.js	Replaced legacy DataTable init with serverSide/ajax; added selectedStudentCids, selectedSubmissions, submissions_to_cud; implemented columns, createdRow, drawCallback, delegated handlers for dynamic elements; added toggleAllRows, toggleRow, updateSelectAllCheckbox, and updateSelectedCount; removed old pagination/hardcoded-row hacks.
View: Table Header & Template Simplification app/views/submissions/index.html.erb	Removed server-rendered tbody and per-row markup, selected-count placeholder, and Regrade All block; simplified header generation to include select-all checkbox and sortable headers; retained modals/placeholders for annotations.

Sequence Diagram(s)

sequenceDiagram
    participant User
    participant Browser as Browser (manage_submissions.js)
    participant Server as Server (SubmissionsController)
    participant DB as Database

    rect rgba(230,245,255,0.8)
    Note over User,Browser: Initial page load (HTML)
    User->>Browser: GET /submissions
    Browser->>Server: GET /submissions (HTML)
    Server->>DB: Query scaffold data (limited)
    DB-->>Server: Return scaffold
    Server-->>Browser: Render index view (DataTables config + headers)
    Browser->>Browser: Initialize DataTables (serverSide)
    end

    rect rgba(245,230,255,0.8)
    Note over Browser,Server: DataTables requests rows
    Browser->>Server: AJAX GET /submissions.json (draw,start,length,search,order)
    Server->>DB: Query submissions with filters/sort/limit (may compute score)
    DB-->>Server: Return rows
    Server->>Server: format_submission_for_datatable per row
    Server-->>Browser: JSON (data, draw, recordsTotal, recordsFiltered)
    Browser->>Browser: createdRow + drawCallback -> render row HTML, checkboxes, actions
    end

    rect rgba(230,255,235,0.8)
    Note over User,Browser: Selection & batch actions
    User->>Browser: Click row checkbox / select-all
    Browser->>Browser: toggleRow / toggleAllRows -> update selections, UI highlight
    Browser->>Browser: updateSelectedCount() -> enable/disable batch actions
    end

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45–75 minutes

• Focus review on:
  • app/controllers/submissions_controller.rb: search/sort correctness (especially computed-score sort), record counts, and format_submission_for_datatable data/HTML.
  • app/assets/javascripts/manage_submissions.js: DataTables columns mapping, createdRow/drawCallback selection persistence, delegated event handlers, and batch-action endpoint wiring.
  • Column ordering and header ↔ DataTables column index alignment in app/views/submissions/index.html.erb.

Possibly related PRs

• autolab/Autolab#2248 — Overlaps same files and the move to DataTables/server-side loading and selection refactor.
• autolab/Autolab#2277 — Directly touches selection/count logic in manage_submissions.js, overlapping selection behavior changes.
• autolab/Autolab#2287 — Modifies select-all and per-row toggle and batch-action handling in manage_submissions.js, closely related to this refactor.

Suggested reviewers

• KesterTan
• coder6583
• jhs-panda

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 20.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title "Manage submissions speed" clearly describes the main objective of the changeset—optimizing the performance of the manage submissions page through server-side pagination.
Description check	✅ Passed	The description covers the key required sections: a clear summary of changes (server-side pagination implementation), motivation explaining the performance problem and its solution, and testing notes indicating local validation.

✨ Finishing touches

• [ ] 📝 Generate docstrings

🧪 Generate unit tests (beta)

• [ ] Create PR with unit tests
• [ ] Post copyable unit tests in a comment
• [ ] Commit unit tests in branch manage-submissions-speed

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[KesterTan]

Regrade all causes the whole page to re-render, the submissions seem to be empty for a while before it is loaded again.

As a result, the tooltip for regrade all also dissapears.

[dwang3851]

Regrade all causes the whole page to re-render, the submissions seem to be empty for a while before it is loaded again.

As a result, the tooltip for regrade all also dissapears.

The tooltip for regrade all does not disappear for me, was unable to reproduce this behavior

[KesterTan]

https://github.com/user-attachments/assets/e6e5faa1-5870-4fae-811d-523e969dff74

Check recording above, there should be a tooltip that says x number of submissions regraded but none is shown.