Separate visibility from permissions — Boundary detective

PART I

Warm-up

Reconnect with a useful idea before starting separate visibility from permissions. 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

Check revocation before export release

Use two decision columns: whether the operation is exposed, and whether the current caller may perform it on the chosen resource. This prevents both dangerous overgranting and confusing diagnostics. User interface choices can explain the rule, but host decisions must remain authoritative.

Exercise exportPreview is visible to all installed mods. Mod M may export its own asset A to local destination L. Exporting other mod asset B or remote destination R requires separate grants not present here. Resource existence and current availability are additional checks.

Supplied case: M’s A→R grant is revoked after rendering preview but before the host releases export bytes.

Worked reasoning: Under this exercise, release checks current authority. Refuse the transfer and cleanup/retain prepared bytes under a documented owner policy. Successful rendering does not complete authorized release.

Contrast and diagnosis: Checking permissions only when the button is rendered leaves a revocation gap.

Worked reasoning and supplied artifact

// Disposable exercise fixture / host-contract notes; not executable API syntax.
// Supplied input: M’s A→R grant is revoked after rendering preview but before the host releases export bytes.
// Worked prediction: Under this exercise, release checks current authority. Refuse the transfer and cleanup/retain prepared bytes under a documented owner policy. Successful rendering does not complete authorized release.
// Rejected alternative: Checking permissions only when the button is rendered leaves a revocation gap.

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: Restricted automation extension. Build a small, understandable change around separate visibility from permissions.

Trace grant→prepare→revoke→release and state resource/message outcomes.

What to produce

Trace grant→prepare→revoke→release and state resource/message outcomes. Include input → intermediate decision/state → predicted outcome, with any required host rule stated explicitly.

• 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 wuix.widget;
const button = widget.Button({
    text: "Continue",
    events: {
        click: fnc() -> void {
            navigator.open("dashboard");
        }
    }
});

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.

• Check revocation before export release
• Explain the decision for the supplied case, then independently work the changed fixture.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

In one or two sentences, name the decisive rule in “Check revocation before export release” and predict the outcome of one changed input from your independent fixture. State which host behavior still needs real verification.

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