Docs: Add documentation for Widget Optimization

src/.vuepress/sidebars/widgets.js

@@ -46,7 +46,15 @@ module.exports = [
           'rendering-repeaters',
           'rendering-html-attribute',
           'rendering-inline-editing',
+        ]
+      },
+      'widget-optimization',
+      {
+        collapsable: false,
+        sidebarDepth: -1,
+        children: [
           'widget-output-caching',
+          'widget-inner-wrapper',
         ]
       },
     ]

src/widgets/widget-inner-wrapper.md

@@ -0,0 +1,94 @@
+# Widget DOM Optimization
+
+<Badge type="tip" vertical="top" text="Elementor Core" /> <Badge type="warning" vertical="top" text="Intermediate" />
+
+Elementor widgets define define their own markup in the `render()` method. However, Elementor wraps each widget in two `<div>` elements, the outer `<div class="elementor-widget">` element and the inner `<div class="elementor-widget-container">` element. These additional wrapper allow Elementor to add additional styles like background, margins, borders, motion effect etc.
+
+Two wrapper for each widget increase the overall DOM size, reducing page performance. To overcome this, developers can use the `has_widget_inner_wrapper()` method to control the number of wrapper elements the widget has.
+
+By switching to a single wrapper, a widget can reduces the DOM size and optimize it's footprint on the page. However, existing widgets that rely on the inner `.elementor-widget-container` wrapping element to style widgets, can keep backwards compatibility.
+
+## Widget Markup
+
+The current, unoptimized widget markup includes two wrapping elements:
+
+```html
+<div class="elementor-widget elementor-widget-{widget-name}">
+	<div class="elementor-widget-container">
+		...
+	</div>
+</div>
+```
+
+The optimized markup, has only one wrapping element:
+
+```html
+<div class="elementor-widget elementor-widget-{widget-name}">
+	...
+</div>
+```
+
+By default, Elementor uses the unoptimized markup for backward compatibility.
+
+## Examples
+
+### Optimized Widget DOM
+
+To reduce the DOM size, developers can use the `has_widget_inner_wrapper()` method in the widget class, as shown below:
+
+```php
+<?php
+class Elementor_Test_Widget extends \Elementor\Widget_Base {
+
+	protected function has_widget_inner_wrapper(): bool {
+		return false;
+	}
+
+}
+```
+
+This implementation instructs Elementor to render the widget with a single `<div>` wrapper.
+
+### Retaining Unoptimized Widget DOM (for BC)
+
+Legacy widgets that rely on the `.elementor-widget-container` class can continue using the unoptimized DOM by setting the method to return `true`:
+
+```php{4-6,16}
+<?php
+class Elementor_Test_Widget extends \Elementor\Widget_Base {
+
+	protected function has_widget_inner_wrapper(): bool {
+		return true;
+	}
+
+	protected function register_controls(): void {
+
+		$this->add_control(
+			'color',
+			[
+				'label' => esc_html__( 'Color', 'textdomain' ),
+				'type' => \Elementor\Controls_Manager::COLOR,
+				'selectors' => [
+					'{{WRAPPER}} > .elementor-widget-container h3' => 'color: {{VALUE}};',
+				],
+			]
+		);
+	}
+
+	protected function render(): void {
+		?>
+		<h3>
+			...
+		</h3>
+		<?php
+	}
+}
+```
+
+This widget can't use the optimized DOM capability as is uses the inner `.elementor-widget-container` CSS class to style the widget. Therefore, setting `has_widget_inner_wrapper()` to `true` will make sure that Elementor won't remove the inner wrapper for this widget.
+
+## Notes
+
+Please note that retaining unoptimized DOM is a temporary solution that allows addon developers to maintain compatibility while updating their code. The ultimate goal is to transition all widgets to use the optimized single-wrapper structure.
+
+Optimized DOM for widget wrappers is not only setting `has_widget_inner_wrapper()` to `false`, it requires removal of `.elementor-widget-container` from all files, including PHP, CSS and JS.

src/widgets/widget-optimization.md

@@ -0,0 +1,23 @@
+# Widget Optimization
+
+<Badge type="tip" vertical="top" text="Elementor Core" /> <Badge type="warning" vertical="top" text="Intermediate" />
+
+Elementor offers several methods and best practices to optimize widgets and improve performance. The optimizations are not implemented for all the widgets to keep backwards compatibility for older websites. In addition, each widget has its own characteristics. The widget developer needs to add some extra for Elementor to make sure Elementor knows how to process it.
+
+## Performance Optimization Methods
+
+Elementor has two performance optimization methods:
+
+```php
+class Elementor_Test_Widget extends \Elementor\Widget_Base {
+
+	public function has_widget_inner_wrapper(): bool {}
+
+	protected function is_dynamic_content(): bool {}
+
+}
+```
+
+* **DOM Optimization** - The `has_widget_inner_wrapper()` method lets you determine whether the widget uses optimized DOM structure or not.
+
+* **Element Output Caching** - The `is_dynamic_content()` method lets you determine whether the widget returns dynamic content, to cache the element HTML output or not.

src/widgets/widget-structure.md

@@ -40,6 +40,8 @@ class Elementor_Test_Widget extends \Elementor\Widget_Base {
 
 	public function get_style_depends(): array {}
 
+	public function has_widget_inner_wrapper(): bool {}
+
 	protected function is_dynamic_content(): bool {}
 
 	protected function register_controls(): void {}