| name | roojs-coding-standards |
| description | Enforces Roo.js JavaScript coding standards for this project. Use when implementing, editing, or reviewing Roo.js code, Roo.bootstrap components, Roo.extend classes, XComponent modules, or any JavaScript in this repository. |
Roo.js Coding Standards
Mandatory for all Roo.js implementation work in this repository.
Before writing or changing code
- Read docs/coding-standards.md — canonical, full standards.
- If building or changing components, also read docs/building-components.md.
- Match surrounding code in the file you are editing; when in doubt, follow the docs above.
Do not rely on general JavaScript style or other projects' conventions. This project's Roo.js rules override them.
Critical rules (never violate)
These are called out in the doc as CRITICAL or FORBIDDEN:
| Rule | Requirement |
|---|
| Underscore prefix | No new _name variables or properties (except established framework names like _tree, _strings) |
| Shared mutable defaults | Never [] or {} on the Roo.extend prototype — use false and lazy init |
| String building in loops | No s += "x" in loops — use Array(n).join or array + join |
| Character looping | No char-by-char string loops — use indexOf, split, replace, regex |
| Template literals | Use + concatenation unless the user explicitly asks for backticks |
| Unset values | Use false, not null, for optional Roo state |
High-priority patterns
Apply these on every change (details and examples in the doc):
- JSDoc: Multiline
/** ... */ with @class, @cfg, @param, @return, @event as appropriate — not one-liners for behaviour.
- Braces: Constructor
function(config) { same line; prototype methods in Roo.extend put { on the next line; control structures if (x) { same line, never one-line if.
this.: Always prefix instance properties and methods inside component methods.- Temp variables: Inline single-use and trivial aliases; alias only 4+ step chains.
- Nesting: Early return /
continue; flat loop bodies; prefer switch over long if/else if chains.
- Defaults: Scalar defaults on prototype in
Roo.extend; per-instance collections in constructor or lazy init.
- Methods: Prefer extending
onRender, getAutoCreate, etc.; no new helpers unless the task requires them.
- Debug:
Roo.debug && Roo.log(...) — no class/method names or timestamps in messages.
- Structure:
Roo.namespace → constructor → Roo.extend → lifecycle overrides only when needed.
Terminology
- Element — thin DOM wrapper (
Roo.Element, Roo.bootstrap.Element).
- Component — widget extending
Roo.Component / Roo.bootstrap.Component.
Verification checklist
Before finishing a Roo.js change:
Additional resources
