Design font fallback and licensing checks — Boundary detective

PART I

Warm-up

Reconnect with a useful idea before starting design font fallback and licensing checks. 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

Handle a glyph no configured font covers

Font choice combines visual coverage, metrics, availability and licensing. The source does not grant redistribution rights or guarantee installed fonts. Each exercise supplies a license or coverage fixture; conclusions apply to that fixture rather than giving general legal or platform advice.

Configured fonts Maple and Cedar both lack glyph Ж. Host contract reports missing-glyph status and shows a replacement marker; it does not download fonts automatically. Required label is Job Ж.

Worked reasoning: Latin glyphs resolve normally, but Ж remains uncovered and produces the specified marker. The interface should retain the original text data and report a coverage gap rather than claiming exact rendering.

Failed alternative: Silently replacing the source text with J changes user data and hides the font problem.

Worked reasoning and supplied artifact

Required text:Job Ж
Coverage Ж:Maple no,Cedar no
Render policy:replacement marker +missing-glyph status
Source text:preserved exactly
No auto-download promise

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 design font fallback and licensing checks.

Review text Lot Я under fonts that lack Я. Specify preserved source, visible fallback status and a requirement for an approved covering font.

What to produce

A missing-glyph ledger and an honest content-preservation plan.

• 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.

• Handle a glyph no configured font covers
• Review text Lot Я under fonts that lack Я. Specify preserved source, visible fallback status and a requirement for an approved covering font.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Separate source content from the fallback glyph used to display it.

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