Define component parameter contracts — Connect the previous skills

PART I

Warm-up

Reconnect with a useful idea before starting define component parameter contracts. 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

Compose parameters without hidden unit conversions

A component parameter contract states representation, meaning, allowed range, defaults and update behavior. A correct-looking configuration can violate any one of these. Keep the public contract independent from the native hosts private implementation; proposed WS object notation does not validate inputs by itself.

Panel width is logical units; supplied bitmap width is physical pixels. At scale2, one logical unit is two physical pixels. A360-pixel bitmap must fit a panel180 logical units wide without stretching.

Worked reasoning: Convert bitmap width360px /2=180 logical units before comparing. It fits exactly. Comparing360 directly with180 mixes units and falsely declares overflow.

Failed alternative: Dividing the panel width instead produces90 and applies the conversion in the wrong direction.

Worked reasoning and supplied artifact

Scale:2 physical px/logical unit
Bitmap:360 physical px ->180 logical units
Panel:180 logical units
Comparison:180<=180 ->fit

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: Accessible service console. Build a small, understandable change around define component parameter contracts.

Evaluate a450px asset at scale3 in a160-logical-unit panel. Record units at every step.

What to produce

A unit-conversion table and component input/output contract.

• 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.button;
import wuix.layout;
domain Login {
    const screen = {
        layout: { type: "column", padding: [24, 32], gap: 16 },
        components: [{ type: "text", value: "Welcome back" }]
    };
    fnc show() -> void {
        wuix.mount("main", screen);
    }
}

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.

• Compose parameters without hidden unit conversions
• Evaluate a450px asset at scale3 in a160-logical-unit panel. Record units at every step.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Attach units to both sides of every geometry comparison.

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