---
name: component-785a4ba38ac6
description: Generate an Angular component with signals, OnPush, and host-based styling following Momentum CMS conventions. Use when creating new UI components in any library.
argument-hint: <library> <component-name>
---

# Generate Angular Component

Create an Angular component following Momentum CMS conventions.

## Arguments

- First argument: Library path (e.g., "admin", "ui", "admin/components")
- Second argument: Component name in kebab-case (e.g., "data-table", "field-renderer")

## File Naming Convention

Momentum CMS uses **short file names without the `.component` infix**. This is a deliberate project convention — do NOT follow the Angular CLI default of `.component.ts`.

| File      | Name it          | NOT                            |
| --------- | ---------------- | ------------------------------ |
| Component | `<name>.ts`      | ~~`<name>.component.ts`~~      |
| Template  | `<name>.html`    | ~~`<name>.component.html`~~    |
| Tests     | `<name>.spec.ts` | ~~`<name>.component.spec.ts`~~ |

For example, a component called `data-table` produces:

- `data-table.ts`
- `data-table.html` (only if template is complex)
- `data-table.spec.ts`

## Steps

1. Create component files in `libs/<library>/src/lib/<component>/`:
   - `<component>.ts` — the component class (NOT `<component>.component.ts`)
   - `<component>.html` — template, only if complex (NOT `<component>.component.html`)
   - `<component>.spec.ts` — tests (NOT `<component>.component.spec.ts`)

2. Use this template for the component:

```typescript
import { ChangeDetectionStrategy, Component, computed, input, output, signal, inject } from '@angular/core';

@Component({
  selector: 'mcms-<component-name>',
  host: { class: 'block' },
  template: `
    <!-- Template here -->
  `,
  changeDetection: ChangeDetectionStrategy.OnPush,
})
export class <PascalName>Component {
  // Signal inputs (use proper types, never `any`)
  readonly data = input.required<DataType>();

  // Optional inputs with defaults
  readonly disabled = input(false);

  // Signal outputs
  readonly valueChange = output<ValueType>();

  // Internal state
  private readonly _loading = signal(false);

  // Computed values
  readonly loading = this._loading.asReadonly();
  readonly hasData = computed(() => !!this.data());

  // Injected services
  private readonly http = inject(HttpClient);
}
```

3. Export from library's `index.ts`:

```typescript
export { <PascalName>Component } from './lib/<component>/<component>';
```

Note: the import path ends with `/<component>` (the short filename), NOT `/<component>.component`.

## Key Conventions

- **NO `standalone: true`** — default in Angular 21, redundant (ESLint enforced)
- **NO `any` types** — use proper interfaces (ESLint enforced)
- **NO `CommonModule` import** — unnecessary in Angular 21
- **NO `.component.ts` suffix** — use plain `.ts` (project convention, see File Naming above)
- Always set `changeDetection: ChangeDetectionStrategy.OnPush` — never use Default
- Use `input()` and `input.required()` for inputs — never use `@Input()` decorator
- Use `output()` for outputs — never use `@Output()` decorator
- Use `signal()` for internal state, `computed()` for derived values
- Use `inject()` for dependency injection — never use constructor injection
- Use `@for`/`@if`/`@switch` control flow — never use `*ngFor`/`*ngIf`/`[ngSwitch]`
- Prefix selectors with `mcms-`

## UI Component Patterns

### No Wrapping Divs

Angular components create a host element. Style the host directly — do NOT add wrapper divs:

```typescript
@Component({
  selector: 'mcms-button',
  host: { class: 'inline-flex items-center gap-2' },
  template: `<ng-content />`,
})
```

NOT:

```typescript
// BAD: unnecessary wrapper div
template: `<div class="inline-flex items-center gap-2"><ng-content /></div>`,
```

### Class Configuration

Accept a `class` input for Tailwind customization via `hostClasses()` computed:

```typescript
@Component({
	selector: 'button[mcms-button]',
	host: { '[class]': 'hostClasses()' },
	template: `<ng-content />`,
	changeDetection: ChangeDetectionStrategy.OnPush,
})
export class McmsButtonComponent {
	readonly variant = input<'primary' | 'secondary'>('primary');
	readonly class = input('');

	readonly hostClasses = computed(
		() => `${baseClasses} ${variantClasses[this.variant()]} ${this.class()}`,
	);
}
```

### Theme Service

Use `McmsThemeService` for dark mode support:

```typescript
import { McmsThemeService } from '@momentumcms/admin';

@Component({...})
export class MyComponent {
  private readonly theme = inject(McmsThemeService);

  toggleDarkMode(): void {
    this.theme.toggleTheme();
  }

  readonly isDark = this.theme.isDark;           // computed signal
  readonly currentTheme = this.theme.theme;      // 'light' | 'dark' | 'system'
}
```

### App Tailwind Setup

Apps using the admin library must:

1. **tailwind.config.js** — Use the admin preset and include library sources:

```javascript
const adminPreset = require('../../libs/admin/tailwind.preset');

module.exports = {
	presets: [adminPreset],
	content: [
		join(__dirname, 'src/**/!(*.stories|*.spec).{ts,html}'),
		join(__dirname, '../../libs/admin/src/**/*.{ts,html}'),
		...createGlobPatternsForDependencies(__dirname),
	],
};
```

2. **styles.css** — Include CSS variables inline (Angular's esbuild can't resolve library CSS imports):

```css
@tailwind base;
@tailwind components;
@tailwind utilities;

@layer base {
	:root {
		--mcms-background: 0 0% 100%;
		--mcms-foreground: 222 47% 11%;
		/* ... copy from libs/admin/src/styles/theme.css */
	}
	.dark {
		/* dark mode variables */
	}
}
```


---
Source attribution: DonaldMurillo
Original project: https://github.com/DonaldMurillo/momentum-cms/blob/2655497e37d840a2734d6c845d6948239ff1c980/.claude/skills/component/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2024-present Momentum CMS Contributors

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: DonaldMurillo
Original project: https://github.com/DonaldMurillo/momentum-cms/blob/2655497e37d840a2734d6c845d6948239ff1c980/.claude/skills/component/SKILL.md
Attribution basis: Source repository record

Fields of work: Design, Development & Engineering
Roles: Frontend Developer, Product Designer, UX Designer
Specialties: Frontend, Testing
Tools: Momentum Cms
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 631dcf778a983e04c31f919f25bc0087beb70ee24a522b9a9e6b2e899e64c1ec