Separate cached cards from navigation fallback
See this course’s project requirements
A localhost reference-card app with an explicit asset cache, offline fallback, visible cache version and a controlled update/cleanup test.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- Create an exact cache inventory and a visible list of excluded offline behavior.
- Record the local secure context and separate worker registration, installation, and page control.
- Produce cache-entry evidence and a controlled required-asset failure/repair record.
- Record actual cached reload and failed-network navigation fallback behavior separately.
- Produce a controlled update/activation record proving the new version and bounded cache cleanup.
- Deliver source, policy assertions, version evidence, performed browser tests, and scoped cleanup/limits.
Review and revise
Use these criteria to check your work and choose what to improve.
- The implementation or declared simulation follows the supplied contract and retains inspectable original inputs.
- Normal, boundary and rejected cases are recorded with expected versus observed results.
- The changed case has a correct explanation and does not rely on hidden state.
- The project includes source, outputs, instructions and honest tool, privacy and verification limits.
Want more background?
The idea in everyday life
In a fresh dedicated folder place index.html, cards.css, offline.html, sw.mjs, cache-policy.mjs and test-cache.mjs. Serve only that folder with python3 -m http.server 8765 --bind 127.0.0.1 and open http://localhost:8765/index.html.
A known cached asset can be returned directly; an uncached navigation tries the network and falls back only when that fetch fails.
Separate cached cards from navigation fallback — original worked practice
A known cached asset can be returned directly; an uncached navigation tries the network and falls back only when that fetch fails.
In a fresh dedicated folder place index.html, cards.css, offline.html, sw.mjs, cache-policy.mjs and test-cache.mjs. Serve only that folder with python3 -m http.server 8765 --bind 127.0.0.1 and open http://localhost:8765/index.html.
1. Step 1
After control is observed, stop the local server with Ctrl+C and reload index.html.
You should see: The installed selected card should remain available offline.
A known cached asset can be returned directly; an uncached navigation tries the network and falls back only when that fetch fails.
2. Step 2
Navigate to http://localhost:8765/not-cached.html while the server remains stopped.
You should see: The navigation fallback displays the offline message.
A known cached asset can be returned directly; an uncached navigation tries the network and falls back only when that fetch fails.
3. Step 3
Read the two fetch branches and compare cached-asset lookup with fetch().catch for navigation.
You should see: Known assets and failed uncached navigation have different handling.
A known cached asset can be returned directly; an uncached navigation tries the network and falls back only when that fetch fails.
4. Step 4
Record actual reload/fallback outcomes and any failed requests; do not substitute a policy test for browser evidence.
You should see: A cached-versus-fallback acceptance matrix.
A known cached asset can be returned directly; an uncached navigation tries the network and falls back only when that fetch fails.
What to finish
Record actual cached reload and failed-network navigation fallback behavior separately.
Watch for this
Assuming fetch catch handles every HTTP error status or reporting offline without stopping the server.
How can I tell I understand it?
Demonstrate the rule: A known cached asset can be returned directly; an uncached navigation tries the network and falls back only when that fetch fails. Use the supplied variant to distinguish a changed result from a broken implementation.
Quick knowledge check
Answer all 3 questions. Get at least 2 right and the lesson completes automatically.
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Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.
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Source & access notes · checked 2026-10-01
Relevant documented module/API behavior inspected during expansion authoring; actual execution evidence is recorded separately. No grant eligibility is established.
Access: Official page retrieved with the web reader on 2026-10-01. Documentation reading does not certify execution in every native tool or browser.
Reuse: Original local practice files, fictional data, worked examples and questions. Concepts paraphrased and linked; source exercises are not copied.
Source & access notes · checked 2026-10-01
Relevant documented module/API behavior inspected during expansion authoring; actual execution evidence is recorded separately. No grant eligibility is established.
Access: Official page retrieved with the web reader on 2026-10-01. Documentation reading does not certify execution in every native tool or browser.
Reuse: Original local practice files, fictional data, worked examples and questions. Concepts paraphrased and linked; source exercises are not copied.
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