Angular V2

Angular Expert

Overview

This public intake copy packages plugins/antigravity-awesome-skills/skills/angular from https://github.com/sickn33/antigravity-awesome-skills into the native Omni Skills editorial shape without hiding its origin.

Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow.

This intake keeps the copied upstream files intact and uses metadata.json plus ORIGIN.md as the provenance anchor for review.

Angular Expert Master modern Angular development with Signals, Standalone Components, Zoneless applications, SSR/Hydration, and the latest reactive patterns.

Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: Safety, Angular Version Timeline, 1. Signals: The New Reactive Primitive, 2. Standalone Components, 3. Zoneless Angular, 4. Server-Side Rendering & Hydration.

When to Use This Skill

Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request.

• Building new Angular applications (v20+)
• Implementing Signals-based reactive patterns
• Creating Standalone Components and migrating from NgModules
• Configuring Zoneless Angular applications
• Implementing SSR, prerendering, and hydration
• Optimizing Angular performance

Operating Table

Workflow

This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow.

1. Assess the Angular version and project structure
2. Apply modern patterns (Signals, Standalone, Zoneless)
3. Implement with proper typing and reactivity
4. Validate with build and tests
5. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task.
6. Read the overview and provenance files before loading any copied upstream support files.
7. Load only the references, examples, prompts, or scripts that materially change the outcome for the current request.

Imported Workflow Notes

Imported: Instructions

1. Assess the Angular version and project structure
2. Apply modern patterns (Signals, Standalone, Zoneless)
3. Implement with proper typing and reactivity
4. Validate with build and tests

Imported: Safety

• Always test changes in development before production
• Gradual migration for existing apps (don't big-bang refactor)
• Keep backward compatibility during transitions

Examples

Example 1: Ask for the upstream workflow directly

Use @angular-v2 to handle <task>. Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer.

Explanation: This is the safest starting point when the operator needs the imported workflow, but not the entire repository.

Example 2: Ask for a provenance-grounded review

Review @angular-v2 against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why.

Explanation: Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection.

Example 3: Narrow the copied support files before execution

Use @angular-v2 for <task>. Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding.

Explanation: This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default.

Example 4: Build a reviewer packet

Review @angular-v2 using the copied upstream files plus provenance, then summarize any gaps before merge.

Explanation: This is useful when the PR is waiting for human review and you want a repeatable audit packet.

Best Practices

Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution.

• Keep the imported skill grounded in the upstream repository; do not invent steps that the source material cannot support.
• Prefer the smallest useful set of support files so the workflow stays auditable and fast to review.
• Keep provenance, source commit, and imported file paths visible in notes and PR descriptions.
• Point directly at the copied upstream files that justify the workflow instead of relying on generic review boilerplate.
• Treat generated examples as scaffolding; adapt them to the concrete task before execution.
• Route to a stronger native skill when architecture, debugging, design, or security concerns become dominant.

Troubleshooting

Problem: The operator skipped the imported context and answered too generically

Symptoms: The result ignores the upstream workflow in plugins/antigravity-awesome-skills/skills/angular, fails to mention provenance, or does not use any copied source files at all. Solution: Re-open metadata.json, ORIGIN.md, and the most relevant copied upstream files. Load only the files that materially change the answer, then restate the provenance before continuing.

Problem: The imported workflow feels incomplete during review

Symptoms: Reviewers can see the generated SKILL.md, but they cannot quickly tell which references, examples, or scripts matter for the current task. Solution: Point at the exact copied references, examples, scripts, or assets that justify the path you took. If the gap is still real, record it in the PR instead of hiding it.

Problem: The task drifted into a different specialization

Symptoms: The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. Solution: Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind.

Imported Troubleshooting Notes

Imported: Common Troubleshooting

Related Skills

• @00-andruia-consultant-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @10-andruia-skill-smith-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @20-andruia-niche-intelligence-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @2d-games - Use when the work is better handled by that native specialization after this imported skill establishes context.

Additional Resources

Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding.

• README.md
• metadata.json

Imported Reference Notes

Imported: Resources

• Angular.dev Documentation
• Angular Signals Guide
• Angular SSR Guide
• Angular Update Guide
• Angular Blog

Imported: Angular Version Timeline

Imported: 1. Signals: The New Reactive Primitive

Signals are Angular's fine-grained reactivity system, replacing zone.js-based change detection.

Core Concepts

import { signal, computed, effect } from "@angular/core";

// Writable signal
const count = signal(0);

// Read value
console.log(count()); // 0

// Update value
count.set(5); // Direct set
count.update((v) => v + 1); // Functional update

// Computed (derived) signal
const doubled = computed(() => count() * 2);

// Effect (side effects)
effect(() => {
  console.log(`Count changed to: ${count()}`);
});

Signal-Based Inputs and Outputs

import { Component, input, output, model } from "@angular/core";

@Component({
  selector: "app-user-card",
  standalone: true,
  template: `
    <div class="card">
      <h3>{{ name() }}</h3>
      <span>{{ role() }}</span>
      <button (click)="select.emit(id())">Select</button>
    </div>
  `,
})
export class UserCardComponent {
  // Signal inputs (read-only)
  id = input.required<string>();
  name = input.required<string>();
  role = input<string>("User"); // With default

  // Output
  select = output<string>();

  // Two-way binding (model)
  isSelected = model(false);
}

// Usage:
// <app-user-card [id]="'123'" [name]="'John'" [(isSelected)]="selected" />

Signal Queries (ViewChild/ContentChild)

import {
  Component,
  viewChild,
  viewChildren,
  contentChild,
} from "@angular/core";

@Component({
  selector: "app-container",
  standalone: true,
  template: `
    <input #searchInput />
    <app-item *ngFor="let item of items()" />
  `,
})
export class ContainerComponent {
  // Signal-based queries
  searchInput = viewChild<ElementRef>("searchInput");
  items = viewChildren(ItemComponent);
  projectedContent = contentChild(HeaderDirective);

  focusSearch() {
    this.searchInput()?.nativeElement.focus();
  }
}

When to Use Signals vs RxJS

Imported: 2. Standalone Components

Standalone components are self-contained and don't require NgModule declarations.

Creating Standalone Components

import { Component } from "@angular/core";
import { CommonModule } from "@angular/common";
import { RouterLink } from "@angular/router";

@Component({
  selector: "app-header",
  standalone: true,
  imports: [CommonModule, RouterLink], // Direct imports
  template: `
    <header>
      <a routerLink="/">Home</a>
      <a routerLink="/about">About</a>
    </header>
  `,
})
export class HeaderComponent {}

Bootstrapping Without NgModule

// main.ts
import { bootstrapApplication } from "@angular/platform-browser";
import { provideRouter } from "@angular/router";
import { provideHttpClient } from "@angular/common/http";
import { AppComponent } from "./app/app.component";
import { routes } from "./app/app.routes";

bootstrapApplication(AppComponent, {
  providers: [provideRouter(routes), provideHttpClient()],
});

Lazy Loading Standalone Components

// app.routes.ts
import { Routes } from "@angular/router";

export const routes: Routes = [
  {
    path: "dashboard",
    loadComponent: () =>
      import("./dashboard/dashboard.component").then(
        (m) => m.DashboardComponent,
      ),
  },
  {
    path: "admin",
    loadChildren: () =>
      import("./admin/admin.routes").then((m) => m.ADMIN_ROUTES),
  },
];

Imported: 3. Zoneless Angular

Zoneless applications don't use zone.js, improving performance and debugging.

Enabling Zoneless Mode

// main.ts
import { bootstrapApplication } from "@angular/platform-browser";
import { provideZonelessChangeDetection } from "@angular/core";
import { AppComponent } from "./app/app.component";

bootstrapApplication(AppComponent, {
  providers: [provideZonelessChangeDetection()],
});

Zoneless Component Patterns

import { Component, signal, ChangeDetectionStrategy } from "@angular/core";

@Component({
  selector: "app-counter",
  standalone: true,
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: `
    <div>Count: {{ count() }}</div>
    <button (click)="increment()">+</button>
  `,
})
export class CounterComponent {
  count = signal(0);

  increment() {
    this.count.update((v) => v + 1);
    // No zone.js needed - Signal triggers change detection
  }
}

Key Zoneless Benefits

• Performance: No zone.js patches on async APIs
• Debugging: Clean stack traces without zone wrappers
• Bundle size: Smaller without zone.js (~15KB savings)
• Interoperability: Better with Web Components and micro-frontends

Imported: 4. Server-Side Rendering & Hydration

SSR Setup with Angular CLI

ng add @angular/ssr

Hydration Configuration

// app.config.ts
import { ApplicationConfig } from "@angular/core";
import {
  provideClientHydration,
  withEventReplay,
} from "@angular/platform-browser";

export const appConfig: ApplicationConfig = {
  providers: [provideClientHydration(withEventReplay())],
};

Incremental Hydration (v20+)

import { Component } from "@angular/core";

@Component({
  selector: "app-page",
  standalone: true,
  template: `
    <app-hero />

    @defer (hydrate on viewport) {
      <app-comments />
    }

    @defer (hydrate on interaction) {
      <app-chat-widget />
    }
  `,
})
export class PageComponent {}

Hydration Triggers

Imported: 5. Modern Routing Patterns

Functional Route Guards

// auth.guard.ts
import { inject } from "@angular/core";
import { Router, CanActivateFn } from "@angular/router";
import { AuthService } from "./auth.service";

export const authGuard: CanActivateFn = (route, state) => {
  const auth = inject(AuthService);
  const router = inject(Router);

  if (auth.isAuthenticated()) {
    return true;
  }

  return router.createUrlTree(["/login"], {
    queryParams: { returnUrl: state.url },
  });
};

// Usage in routes
export const routes: Routes = [
  {
    path: "dashboard",
    loadComponent: () => import("./dashboard.component"),
    canActivate: [authGuard],
  },
];

Route-Level Data Resolvers

import { inject } from '@angular/core';
import { ResolveFn } from '@angular/router';
import { UserService } from './user.service';
import { User } from './user.model';

export const userResolver: ResolveFn<User> = (route) => {
  const userService = inject(UserService);
  return userService.getUser(route.paramMap.get('id')!);
};

// In routes
{
  path: 'user/:id',
  loadComponent: () => import('./user.component'),
  resolve: { user: userResolver }
}

// In component
export class UserComponent {
  private route = inject(ActivatedRoute);
  user = toSignal(this.route.data.pipe(map(d => d['user'])));
}

Imported: 6. Dependency Injection Patterns

Modern inject() Function

import { Component, inject } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { UserService } from './user.service';

@Component({...})
export class UserComponent {
  // Modern inject() - no constructor needed
  private http = inject(HttpClient);
  private userService = inject(UserService);

  // Works in any injection context
  users = toSignal(this.userService.getUsers());
}

Injection Tokens for Configuration

import { InjectionToken, inject } from "@angular/core";

// Define token
export const API_BASE_URL = new InjectionToken<string>("API_BASE_URL");

// Provide in config
bootstrapApplication(AppComponent, {
  providers: [{ provide: API_BASE_URL, useValue: "https://api.example.com" }],
});

// Inject in service
@Injectable({ providedIn: "root" })
export class ApiService {
  private baseUrl = inject(API_BASE_URL);

  get(endpoint: string) {
    return this.http.get(`${this.baseUrl}/${endpoint}`);
  }
}

Imported: 7. Component Composition & Reusability

Content Projection (Slots)

@Component({
  selector: 'app-card',
  template: `
    <div class="card">
      <div class="header">
        <!-- Select by attribute -->
        <ng-content select="[card-header]"></ng-content>
      </div>
      <div class="body">
        <!-- Default slot -->
        <ng-content></ng-content>
      </div>
    </div>
  `
})
export class CardComponent {}

// Usage
<app-card>
  <h3 card-header>Title</h3>
  <p>Body content</p>
</app-card>

Host Directives (Composition)

// Reusable behaviors without inheritance
@Directive({
  standalone: true,
  selector: '[appTooltip]',
  inputs: ['tooltip'] // Signal input alias
})
export class TooltipDirective { ... }

@Component({
  selector: 'app-button',
  standalone: true,
  hostDirectives: [
    {
      directive: TooltipDirective,
      inputs: ['tooltip: title'] // Map input
    }
  ],
  template: `<ng-content />`
})
export class ButtonComponent {}

Imported: 8. State Management Patterns

Signal-Based State Service

import { Injectable, signal, computed } from "@angular/core";

interface AppState {
  user: User | null;
  theme: "light" | "dark";
  notifications: Notification[];
}

@Injectable({ providedIn: "root" })
export class StateService {
  // Private writable signals
  private _user = signal<User | null>(null);
  private _theme = signal<"light" | "dark">("light");
  private _notifications = signal<Notification[]>([]);

  // Public read-only computed
  readonly user = computed(() => this._user());
  readonly theme = computed(() => this._theme());
  readonly notifications = computed(() => this._notifications());
  readonly unreadCount = computed(
    () => this._notifications().filter((n) => !n.read).length,
  );

  // Actions
  setUser(user: User | null) {
    this._user.set(user);
  }

  toggleTheme() {
    this._theme.update((t) => (t === "light" ? "dark" : "light"));
  }

  addNotification(notification: Notification) {
    this._notifications.update((n) => [...n, notification]);
  }
}

Component Store Pattern with Signals

import { Injectable, signal, computed, inject } from "@angular/core";
import { HttpClient } from "@angular/common/http";
import { toSignal } from "@angular/core/rxjs-interop";

@Injectable()
export class ProductStore {
  private http = inject(HttpClient);

  // State
  private _products = signal<Product[]>([]);
  private _loading = signal(false);
  private _filter = signal("");

  // Selectors
  readonly products = computed(() => this._products());
  readonly loading = computed(() => this._loading());
  readonly filteredProducts = computed(() => {
    const filter = this._filter().toLowerCase();
    return this._products().filter((p) =>
      p.name.toLowerCase().includes(filter),
    );
  });

  // Actions
  loadProducts() {
    this._loading.set(true);
    this.http.get<Product[]>("/api/products").subscribe({
      next: (products) => {
        this._products.set(products);
        this._loading.set(false);
      },
      error: () => this._loading.set(false),
    });
  }

  setFilter(filter: string) {
    this._filter.set(filter);
  }
}

Imported: 9. Forms with Signals (Coming in v22+)

Current Reactive Forms

import { Component, inject } from "@angular/core";
import { FormBuilder, Validators, ReactiveFormsModule } from "@angular/forms";

@Component({
  selector: "app-user-form",
  standalone: true,
  imports: [ReactiveFormsModule],
  template: `
    <form [formGroup]="form" (ngSubmit)="onSubmit()">
      <input formControlName="name" placeholder="Name" />
      <input formControlName="email" type="email" placeholder="Email" />
      <button [disabled]="form.invalid">Submit</button>
    </form>
  `,
})
export class UserFormComponent {
  private fb = inject(FormBuilder);

  form = this.fb.group({
    name: ["", Validators.required],
    email: ["", [Validators.required, Validators.email]],
  });

  onSubmit() {
    if (this.form.valid) {
      console.log(this.form.value);
    }
  }
}

Signal-Aware Form Patterns (Preview)

// Future Signal Forms API (experimental)
import { Component, signal } from '@angular/core';

@Component({...})
export class SignalFormComponent {
  name = signal('');
  email = signal('');

  // Computed validation
  isValid = computed(() =>
    this.name().length > 0 &&
    this.email().includes('@')
  );

  submit() {
    if (this.isValid()) {
      console.log({ name: this.name(), email: this.email() });
    }
  }
}

Imported: 10. Performance Optimization

Change Detection Strategies

@Component({
  changeDetection: ChangeDetectionStrategy.OnPush,
  // Only checks when:
  // 1. Input signal/reference changes
  // 2. Event handler runs
  // 3. Async pipe emits
  // 4. Signal value changes
})

Defer Blocks for Lazy Loading

@Component({
  template: `
    <!-- Immediate loading -->
    <app-header />

    <!-- Lazy load when visible -->
    @defer (on viewport) {
      <app-heavy-chart />
    } @placeholder {
      <div class="skeleton" />
    } @loading (minimum 200ms) {
      <app-spinner />
    } @error {
      <p>Failed to load chart</p>
    }
  `
})

NgOptimizedImage

import { NgOptimizedImage } from '@angular/common';

@Component({
  imports: [NgOptimizedImage],
  template: `
    <img
      ngSrc="hero.jpg"
      width="800"
      height="600"
      priority
    />

    <img
      ngSrc="thumbnail.jpg"
      width="200"
      height="150"
      loading="lazy"
      placeholder="blur"
    />
  `
})

Imported: 11. Testing Modern Angular

Testing Signal Components

import { ComponentFixture, TestBed } from "@angular/core/testing";
import { CounterComponent } from "./counter.component";

describe("CounterComponent", () => {
  let component: CounterComponent;
  let fixture: ComponentFixture<CounterComponent>;

  beforeEach(async () => {
    await TestBed.configureTestingModule({
      imports: [CounterComponent], // Standalone import
    }).compileComponents();

    fixture = TestBed.createComponent(CounterComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it("should increment count", () => {
    expect(component.count()).toBe(0);

    component.increment();

    expect(component.count()).toBe(1);
  });

  it("should update DOM on signal change", () => {
    component.count.set(5);
    fixture.detectChanges();

    const el = fixture.nativeElement.querySelector(".count");
    expect(el.textContent).toContain("5");
  });
});

Testing with Signal Inputs

import { ComponentFixture, TestBed } from "@angular/core/testing";
import { ComponentRef } from "@angular/core";
import { UserCardComponent } from "./user-card.component";

describe("UserCardComponent", () => {
  let fixture: ComponentFixture<UserCardComponent>;
  let componentRef: ComponentRef<UserCardComponent>;

  beforeEach(async () => {
    await TestBed.configureTestingModule({
      imports: [UserCardComponent],
    }).compileComponents();

    fixture = TestBed.createComponent(UserCardComponent);
    componentRef = fixture.componentRef;

    // Set signal inputs via setInput
    componentRef.setInput("id", "123");
    componentRef.setInput("name", "John Doe");

    fixture.detectChanges();
  });

  it("should display user name", () => {
    const el = fixture.nativeElement.querySelector("h3");
    expect(el.textContent).toContain("John Doe");
  });
});

Imported: Best Practices Summary

Imported: Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.