PART I
Warm-up
Reconnect with a useful idea before starting separate exposed api from capability permission. 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 a visible navigation request to its resource check
An exposed API answers “which operation can the script name?” A capability answers “which resource may this caller use?” A native Willow programmer must not substitute process-level assumptions for the script host’s resource checks. Trace the requested operation, caller, resource and authorization independently; names such as navigator are exercise-host contracts, not builtins.
The source button registers a click callback that requests navigator.open("dashboard"). Sample request ledger: registration = response described, no navigation yet; click = host invokes callback; operation = open; resource = dashboard; required decision = caller permitted to access dashboard. A visible navigator API establishes none of the resource-specific decision by itself.
Do not claim the dashboard opened at registration time or that importing widgets grants navigation. Exact error/result shapes remain host-defined, so the ledger describes the boundary without inventing a thrown type.
Worked reasoning and supplied artifact
import wuix.widget;
const button = widget.Button({
text: "Continue",
events: {
click: fnc() -> void {
navigator.open("dashboard");
}
}
});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
import wuix.widget;Name the external module this script asks to use. Importing a name does not supply a host resource or grant its capability permissions.
const button = widget.Button({Name a value that this example keeps stable. Inspect the right-hand side for the value or configuration being bound.
text: "Continue",Read this key/value within its containing object. State which parent owns it and the narrow visible behavior it configures.
events: {Read this key/value within its containing object. State which parent owns it and the narrow visible behavior it configures.
click: fnc() -> void {This configuration value is a callback. Registration describes a response; the host contract determines when and with which context it is called.
navigator.open("dashboard");Read this statement in its surrounding contract. Identify which value or host operation it contributes; do not infer an undocumented API.
}Close the nested block or value begun earlier. Match it to its opening boundary to keep the structure readable.
}Close the nested block or value begun earlier. Match it to its opening boundary to keep the structure readable.
});Close the nested block or value begun earlier. Match it to its opening boundary to keep the structure readable.
Try the guided change
Draw registration, click, request and permission decision as four separate moments.
- 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: Safe extension design. Build a small, understandable change around separate exposed api from capability permission.
Plan a route-map button whose click requests the workshop screen. Provide the event/request ledger and an allowed/denied target table under an explicit host contract.
What to produce
A four-moment trace and permission matrix with no claimed navigation execution.
- 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?
The source button registers a click callback that requests navigator.open("dashboard"). Sample request ledger: registration = response described, no navigation yet; click = host invokes callback; operation = open; resource = dashboard; required decision = caller permitted to access dashboard. A visible navigator API establishes none of the resource-specific decision by itself.
Do not claim the dashboard opened at registration time or that importing widgets grants navigation. Exact error/result shapes remain host-defined, so the ledger describes the boundary without inventing a thrown type.
Original learning-path task and reference
Use your Willow knowledge to implement the .ws host integration, explaining which work remains native and which belongs in the script. In a research data workstation, demonstrate separate exposed api from capability permission. 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.
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.
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 a visible navigation request to its resource check
- Draw registration, click, request and permission decision as four separate moments.
- Separate source-backed behavior, host requirements and untested predictions.
One small recap task
Draw registration, click, request and permission decision as four separate moments.
This marks your personal practice record only. It is not a certification or an official workspace assessment.