fix: properties not updating correctly without refresh

[gururaj1512]

Resolves None

Description

What is the purpose of this pull request?

This pull request:

• fix: properties not updating correctly without refresh

Related Issues

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This pull request has the following related issues:

• None

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• Read, understood, and followed the contributing guidelines.

AI Assistance

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• No

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• Test/benchmark generation
• Documentation (including examples)
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If you answered "yes" to using AI assistance, please provide a short disclosure indicating how you used AI assistance. This helps reviewers determine how much scrutiny to apply when reviewing your contribution. Example disclosures: "This PR was written primarily by Claude Code." or "I consulted ChatGPT to understand the codebase, but the proposed changes were fully authored manually by myself.".

I used GitHub Copilot to help trace the bug through the codebase & reading through router.js, on_change.js, and the route handlers to understand how the request flow worked. Once I understood the root cause, I identified the fixes myself and authored the changes manually. The AI mostly helped me navigate unfamiliar parts of the codebase faster.

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@stdlib-js/reviewers

[gururaj1512]

change 1: 400 Bad Request on domainColor, domainDash, etc.

When I tried updating these from the side panel, I kept getting a 400. Tracing it, I found parameterize() in router.js builds regexes without ^/$ anchors, so a POST to /config/axes/0/domainColor was matching the /domain route instead. Since routes are registered alphabetically, axesDomain comes first and its toBoolean transformer choked on values like "#ff0000". Fixed by anchoring the regex:

re = '^' + re + '$';

Bug 2: domainDash changes only reflected after a page refresh

Even after fixing the 400, domainDash updates weren't live. Lil-GUI can't handle arrays natively, so array properties get stringified (e.g. "[5, 5]"). The raw string was being passed directly to state.view.onSignal(), which Vega couldn't interpret. The backend was fine since it parses via toJSON — the mismatch was purely on the frontend signal side. Fixed by parsing the value back before emitting the change event in on_change.js, while keeping the raw string for the server POST:

var val = event.value;
if ( isJSON(val) ) {
    try { val = JSON.parse( val ); } catch ( err ) {}
}

All properties now seem to update correctly.

[kgryte]

LGTM.

[kgryte]

As the CI failure is expected, I'll go ahead and merge.