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name: symfony-sk:js-handler description: Create JavaScript handlers for pages. Use for DOM interactions and API calls. allowed-tools: Read, Write, Edit, Glob, Grep

JavaScript Handler Skill

Mission

Create JavaScript handlers following the project's strict standards.

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Location

front/public/site/js/<feature>/<name>.js

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Standards

MANDATORY: Read and apply ALL rules from:

.claude/rules/javascript-standards.md

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Quick Reference

1. IIFE - (function() { 'use strict'; ... })();
2. No var - const default, let if reassignment
3. Declare locally - Variables closest to usage
4. Assertions - Validate at function entry, throw explicit errors
5. Max 60 lines - Per function
6. Check returns - response.ok, null, undefined
7. No empty catch - Log with context or re-throw
8. No mutation - Return new objects
9. Object mapping - Over switch when possible
10. Bounded loops - Prefer map/filter/reduce

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Translations

Copy// Twig: {{ ['key1', 'key2'] | tradJS }}
// JS: window.trad.key1

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Checklist

See .claude/rules/javascript-standards.md for complete checklist.