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WillowScript (.ws) is a proposed, not-yet-implemented language. Examples and library integrations here are illustrative design exercises, not verified runnable programs.

WillowScript Intermediate · Trace the UI-to-domain-to-host route

Practice event and interface integration — Discover and trace

Practice event and interface integration: discover and trace.

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PART I

Warm-up

Reconnect with a useful idea before starting practice event and interface integration. 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

Trace the UI-to-domain-to-host route

Integration is a sequence of owned transitions. A native interface, event response and domain rule have different contracts. Connect them through explicit input/result/effect edges. WUIX describes proposed native UI, not a browser DOM framework; event payloads, resource handles and lifetime rules must come from the supplied host contract.

The visible preview control is associated with draft D31: title=Help, body=Door stuck. A local domain step validates text, then a WUIX host describes the preview in native UI. No submission is requested.

Follow one user action from its visible control through validation and calculation to an authorized effect. Keep registration separate from delivery, local state separate from durable state, and a predicted outcome separate from host-confirmed evidence. Worked case: Click delivery identifies D31; validation reads its fields; the preview description uses those same values; the host render request targets the permitted preview owner. The trace stops there, without a queue effect.

Compare the tempting alternative: Showing a preview must not be treated as implicit consent to submit. Reusing a submit handler directly can accidentally cross that boundary.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// The visible preview control is associated with draft D31: title=Help, body=Door stuck. A local domain step validates text, then a WUIX host describes the preview in native UI. No submission is requested.
// Click delivery identifies D31; validation reads its fields; the preview description uses those same values; the host render request targets the permitted preview owner. The trace stops there, without a queue effect.

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.

Walk through the example, one line at a time
  1. // Paper trace / supplied exercise-host contract; no execution claimed.

    This comment explains intent for a reader. It is not an operation and should not be counted as an executed result.

  2. // The visible preview control is associated with draft D31: title=Help, body=Door stuck. A local domain step validates text, then a WUIX host describes the preview in native UI. No submission is requested.

    This comment explains intent for a reader. It is not an operation and should not be counted as an executed result.

  3. // Click delivery identifies D31; validation reads its fields; the preview description uses those same values; the host render request targets the permitted preview owner. The trace stops there, without a queue effect.

    This comment explains intent for a reader. It is not an operation and should not be counted as an executed result.

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.

Your drafts remain here. Continue whenever you are ready.

PART IV

Independent practice

Project context: Event-driven team utility. Build a small, understandable change around practice event and interface integration.

Draw the four edges and add an invalid-title case that stops before rendering a success preview.

What to produce

Two UI/domain/host traces with explicit no-submit postconditions.

  • 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.

Need a hint?

Start with the specific transition in this case: Click delivery identifies D31; validation reads its fields; the preview description uses those same values; the host render request targets the permitted preview owner. The trace stops there, without a queue effect.

Showing a preview must not be treated as implicit consent to submit. Reusing a submit handler directly can accidentally cross that boundary.

Original learning-path task and reference

In a rhythm-game audio editor, demonstrate practice event and interface integration. Read the source-grounded example and predict its observable behavior before making changes. Include .ws source and a host-resource contract; compare at least one normal case and one edge case.

import wuix.widget;
import app;
domain Workspace {
    const application = Application({
        name: "Workspace",
        window: { title: "Dashboard", size: [1280, 800] },
        events: {
            "app.ready": fnc() -> void { console.log("Ready"); }
        }
    });
}

Where the original task needs a host API that is not supplied here, write the contract and predictions. Do not invent a runtime result.

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.

Which effect is outside this action?

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.

  • Trace the UI-to-domain-to-host route
  • Draw the four edges and add an invalid-title case that stops before rendering a success preview.
  • Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Mark the edge where a separate Submit action would begin.

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

Your practice, on this browser

No public account is created. Drafts and lesson progress stay in this browser’s local storage. They do not automatically follow you to another device and can be lost if browser storage is cleared.

Export a private progress file to keep a copy, then import it on another browser when you want to move your work. Treat that file as your own writing; it can contain your practice drafts.