Compose playback controls, device recovery contracts, and event cleanup — Build the smallest useful slice

PART I

Warm-up

Reconnect with a useful idea before starting compose playback controls, device recovery contracts, and event cleanup. In one or two sentences, describe the input, output or host boundary from the previous exercise that this lesson builds on. If you are arriving directly, skim the worked example first; there is no locked prerequisite.

A rough note is enough. You can revise it after the example.

PART II

Instruction & guided example

Build the smallest useful sound notification

Proposed WAUDIO describes native audio integration, including MP3 and WAV rather than MP4 support. Loading, configuration, permission and playback are separate outcomes. Every device or control behavior in these exercises is a supplied host contract; no guessed audio methods or real playback are used.

Required notification is a visible Saved message after confirmed save. Optional audio is chime.wav at volume0.4 on explicit user-enabled sound. The host may lack an output device.

Worked reasoning: The smallest dependable slice always shows Saved after save success. It requests sound only when enabled and available under the host contract. A missing device leaves the required visual result intact.

Failed alternative: Making the Saved label depend on sound success blocks required feedback for a user who intentionally muted audio.

Worked reasoning and supplied artifact

Save success ->Saved text
Sound preference off ->no play request
Preference on +device available ->eligible audio request
Preference on +device missing ->visual Saved remains

Illustrative example from the proposed WillowScript design. The language and WUIX/WMATH/WDB/WAUDIO/WTMP services are not implemented in the supplied source. This site has no interpreter, VM or native host and does not execute or certify the snippet.

Try the guided change

Reconstruct the supplied worked case first: list its inputs, intermediate decisions and final artifact. Compare each row with the explanation and identify exactly where the rejected alternative fails. Then use the changed inputs in Part IV for independent work.

• Write the supplied inputs and initial state before following the example.
• Reconstruct each intermediate calculation or host decision, then compare with the worked artifact.
• Explain why the contrasting alternative fails before attempting the changed inputs in Part IV.

PART III

Take a breather

Step back after the guided example. Look away from the screen, stretch, or reread your prediction. This is an optional learning pause, not a timer or an assessment gate.

When you return, try to name the lesson’s key idea without copying its wording. If that feels difficult, return to Part II and trace one line rather than restarting the entire lesson.

PART IV

Independent practice

Project context: Media operations console. Build a small, understandable change around compose playback controls, device recovery contracts, and event cleanup.

Design a Build complete notification with optional tone and a user mute preference. Specify all preference/device combinations.

What to produce

A required/optional effect table and a mute-respecting notification flow.

• State the intended behavior in a sentence before editing.
• Use only source-backed syntax and the host services whose contract you have been given.
• Record a normal case and a boundary or unavailable-resource case.
• Label hand predictions separately from anything actually measured in a supplied toolchain.

Syntax colors are a reading aid, not a compiler. The line you are editing stays uncolored until you move to a different line; capitalization is never changed. Drafts stay on this browser and code is not executed.

import wdb;
domain Inventory {
    const lowStock = wdb.query({
        from: products,
        select: [id, name, stock],
        where: [[ stock < 10 ]],
        order: { by: stock, direction: ascending }
    });
}

PART V

Self-check

Use this check to notice what to revisit. It does not award a private course grade, block another page or claim to verify compiled code. Every answer has a learning explanation.

You may keep exploring even if you are unsure. Use the hint, compare the trace, and revise your explanation.

PART VI

Recap & small task

Bring the idea back to the mod feature you are building. A useful recap connects the mechanism to a decision you can make in your own code.

• Build the smallest useful sound notification
• Design a Build complete notification with optional tone and a user mute preference. Specify all preference/device combinations.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Make the primary result understandable without sound.

This marks your personal practice record only. It is not a certification or an official workspace assessment.