Angular Academy · Lesson

Single-Slot Content Projection

Project content with ng-content.

Single-Slot Content Projection is a free Angular Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Angular Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

What Is Content Projection?

Content projection lets a component receive markup from its parent and render it inside its own template. It is Angular's equivalent of "slots" in web components.

The parent writes content between the component's tags, and the component decides where that content appears.

Why You Need It

Reusable wrappers like cards, dialogs, and panels do not know their content ahead of time. Content projection makes them flexible containers.

Build a card once, fill it with anything
Keep layout logic in the component
Keep content in the consumer

The ng-content Element

The <ng-content> element marks the spot where projected content is placed. A single-slot setup uses exactly one <ng-content> with no select attribute.

@Component({
  selector: 'app-card',
  template: '<div class="card"><ng-content></ng-content></div>'
})
export class CardComponent {}

Using the Component

Whatever the parent places between the component tags is projected into the slot.

<app-card>
  <h2>Hello</h2>
  <p>This text is projected into the card.</p>
</app-card>

Single Slot = One Outlet

With a single unnamed slot, all projected nodes go into the one <ng-content>. There is no filtering; order is preserved exactly as the parent wrote it.

Default Content

You can place fallback markup inside <ng-content>. Modern Angular renders this default content only when the consumer projects nothing into that slot.

<div class="card">
  <ng-content>No content provided.</ng-content>
</div>

Styling Projected Content

Projected content belongs to the parent's view, so it is styled by the parent's styles, not the card's. To reach projected nodes from the card, use ::ng-deep sparingly or rely on global styles.

Content vs View

Angular distinguishes content children (projected in) from view children (declared in the template). This matters for queries like contentChild vs viewChild.

icon = contentChild(IconComponent);

Lifecycle: ngAfterContentInit

Projected content is available after ngAfterContentInit() runs. Use it (or ngAfterContentChecked) to safely read content children.

ngAfterContentInit() {
  console.log('Projected content ready');
}

A Real Panel Example

Here is a complete reusable panel. The consumer fully controls the inside; the panel controls the shell.

@Component({
  selector: 'app-panel',
  template: '<section class="panel"><ng-content></ng-content></section>',
  styles: ['.panel { border: 1px solid #ccc; padding: 16px; }']
})
export class PanelComponent {}

Common Mistake

Placing the same unnamed <ng-content> twice does not duplicate content. Angular only projects into the last matching slot. Use multi-slot projection if you need multiple regions.

Quick Check

Test your understanding of single-slot projection.

Recap

You learned that content projection uses <ng-content> to render parent-supplied markup inside a component. Single-slot projection uses one unnamed outlet, projected content belongs to the parent view, and it becomes available in ngAfterContentInit.

Frequently asked questions

Is the “Single-Slot Content Projection” lesson free?

Yes — the full text of “Single-Slot Content Projection” is free to read here on the web, and the Angular Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Angular Academy course, upgrade to CoddyKit PRO.

What will I learn in “Single-Slot Content Projection”?

Project content with ng-content. You practise Angular Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Angular Academy?

No prior experience is required. Angular Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Single-Slot Content Projection” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Angular Academy lesson?

Yes. Every Angular Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

All lessons in this course

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