Angular Architecture

The Scope Rule (REQUIRED)

"Scope determines structure" - Where a component lives depends on its usage.

Example

features/
  shopping-cart/
    shopping-cart.ts          # Main component = feature name
    components/
      cart-item.ts            # Used ONLY by shopping-cart
      cart-summary.ts         # Used ONLY by shopping-cart
  checkout/
    checkout.ts
    components/
      payment-form.ts         # Used ONLY by checkout
  shared/
    components/
      button.ts               # Used by shopping-cart AND checkout
      modal.ts                # Used by multiple features

Project Structure

src/app/
  features/
    [feature-name]/
      [feature-name].ts       # Main component (same name as folder)
      components/             # Feature-specific components
      services/               # Feature-specific services
      models/                 # Feature-specific types
    shared/                   # ONLY for 2+ feature usage
      components/
      services/
      pipes/
  core/                       # App-wide singletons
    services/
    interceptors/
    guards/
  app.ts
  app.config.ts
  routes.ts
  main.ts

File Naming (REQUIRED)

No .component, .service, .model suffixes. The folder tells you what it is.

✅ user-profile.ts
❌ user-profile.component.ts

✅ cart.ts
❌ cart.service.ts

✅ user.ts
❌ user.model.ts

Style Guide

What We Follow (from official docs)

• inject() over constructor injection
• class and style bindings over ngClass/ngStyle
• protected for template-only members
• readonly for inputs, outputs, queries
• Name handlers for action (saveUser) not event (handleClick)
• Keep lifecycle hooks simple - delegate to well-named methods
• One concept per file

@Component({...})
export class UserProfileComponent {
  // 1. Injected dependencies
  private readonly userService = inject(UserService);
  
  // 2. Inputs/Outputs
  readonly userId = input.required<string>();
  readonly userSaved = output<User>();
  
  // 3. Internal state
  private readonly _loading = signal(false);
  readonly loading = this._loading.asReadonly();
  
  // 4. Computed
  protected readonly displayName = computed(() => ...);
  
  // 5. Methods
  save(): void { ... }
}

What We Override

Commands

# New project
ng new my-app --style=scss --ssr=false

# Component in feature
ng g c features/products/components/product-card --flat

# Service in feature  
ng g s features/products/services/product --flat

# Guard in core
ng g g core/guards/auth --functional

Resources

• https://angular.dev/style-guide

🎯 Selective Reading Rule

Read ONLY files relevant to the request! Check the content map, find what you need.

🔗 Related Skills

Core Principle

"Simplicity is the ultimate sophistication."

• Start simple
• Add complexity ONLY when proven necessary
• You can always add patterns later
• Removing complexity is MUCH harder than adding it

Validation Checklist

Before finalizing architecture:

• Requirements clearly understood
• Constraints identified
• Each decision has trade-off analysis
• Simpler alternatives considered
• ADRs written for significant decisions
• Team expertise matches chosen patterns

When to Use

This skill is applicable to execute the workflow or actions described in the overview.