Nested Layouts

Nested layouts allow you to compose templates in multiple layers. Each layer can define its own structure and pass control to child templates.

1. Basic Concept

$admin = $tpl->slot('content','admin');
$admin->slot('content','dashboard');

Hierarchy:

base → admin → dashboard

2. Layout Structure Example

base.html

<div class="container">
  <div data-slot="content"></div>
</div>

admin.html

<div class="admin-panel">
  <h2>Admin</h2>
  <div data-slot="content"></div>
</div>

dashboard.html

<div>
  <h3 id="title"></h3>
</div>

3. Data Binding in Nested Templates

$admin = $tpl->slot('content','admin');
$dashboard = $admin->slot('content','dashboard');

$dashboard->pick('title')->content('Dashboard');

4. Assignment Inheritance

$tpl->pick('appName')->content('My App');

$admin = $tpl->slot('content','admin');
$dashboard = $admin->slot('content','dashboard');

👉 dashboard can still access appName

5. Multiple Nested Levels

$level1 = $tpl->slot('content','layout1');
$level2 = $level1->slot('content','layout2');
$level3 = $level2->slot('content','page');

👉 Unlimited nesting supported

6. Nested + Includes

$admin = $tpl->slot('content','admin');

$header = $admin->include('#header','header');
$header->pick('user')->content('Tamil');

7. Nested + Loops

$order = $tpl->addLoopItem('orders');

$child = $order->slot('content','order-item');
$child->pick('name')->content('Pizza');

8. Nested + Data Files

// data.php
$admin = $this->slot('content','admin');
$admin->slot('content','dashboard');

9. Execution Flow (Important)

Rendering happens in this order:

1. Base template loads
2. Slot replaced with child template
3. Child template renders
4. Process repeats recursively

10. Common Mistakes

11. Rules

• Slot names must match exactly
• Each slot replaces inner content
• Only first matching slot is used

12. Best Practices

• Keep nesting shallow (2–3 levels ideal)
• Use meaningful layout names (admin, app, page)
• Avoid deeply nested chains unless necessary

13. Real-World Example (Restaurant App)

$app = $tpl->slot('content','app-layout');

$orders = $app->slot('content','orders-page');

$orders->pick('table')->content('Table 5');

14. Performance Notes

• Each level adds DOM processing
• Avoid deep nesting in large pages