# Directives & Pipes

> Composition patterns using HostDirectives and Pure Pipes.

- Skill: `fierzone/directives-pipes` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add fierzone/directives-pipes`
- Raw SKILL.md: https://api.skillmd.com/api/skills/fierzone/directives-pipes/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: fierzone (https://skillmd.com/u/fierzone)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/fierzone/directives-pipes

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# Directives & Pipes

## **Priority: P2 (MEDIUM)**

## Principles

- **Composition**: Use `hostDirectives` to compose behaviors onto components/directives without inheritance.
- **Pure Pipes**: Pipes must be `pure: true` (default). They cache results based on input reference.
- **Directive Logic**: Encapsulate reusable DOM manipulation or behavioral logic in Directives (e.g., `appFocusTrap`, `appTooltip`).

## Guidelines

- **Signal Inputs**: Directives also support signal inputs.
- **Standalone**: All Pipes and Directives must be standalone.

## References

- [Composition](references/composition.md)