SDC components - Images

Canvas provides the canvas:image component for consistent image handling across SDC components. This component is designed for developers creating SDCs and handles responsive images, lazy loading, and modern image optimization automatically.

Using the image component

The canvas:image component is included in other SDC components using Twig’s include function. It provides a standardized way to render images with proper attributes and performance optimizations.

Basic usage

{% include 'canvas:image' with {
  src: 'https://example.com/image.jpg',
  alt: 'Example image',
  width: 600,
  height: 400,
} only %}

Usage with prop values

{% include 'canvas:image' with image|merge({
  loading: 'lazy',
  sizes: '(max-width: 768px) 100vw, 50vw',
  class: 'card--image',
  attributes: create_attribute({
    'data-testid': 'card-component-image',
  }),
} only %}

Component properties

The canvas:image component accepts the following properties:

Required properties

• src: Image source URL. Can be relative, absolute, local, remote, or stream wrapper URI
  • Examples: https://placehold.co/600x400, /sites/default/files/llama.jpg, public://llama.jpg

Optional properties

• alt: Alternative text for accessibility
• width: Image width in pixels (integer)
• height: Image height in pixels (integer)
• sizes: Responsive image sizes attribute (e.g., auto 100vw)
• loading: HTML loading attribute (lazy or eager, defaults to lazy)
• class: Additional CSS classes
• attributes: Drupal attributes object for additional HTML attributes

Defining image props in your SDC

When creating your own SDC component that uses images, define the image properties in your component metadata:

$schema: https://git.drupalcode.org/project/drupal/-/raw/HEAD/core/assets/schemas/v1/metadata.schema.json
name: Card
props:
  type: object
  properties:
    image:
      $ref: json-schema-definitions://canvas.module/image
      type: object
      title: Card image
      examples:
        - src: https://placehold.co/400x300
          alt: Card placeholder image
          width: 400
          height: 300

Responsive image settings

The canvas:image component automatically handles responsive behavior and performance optimizations. You can enhance this with additional properties:

Lazy loading

The component defaults to lazy loading. For above-the-fold images, use eager loading:

{% include 'canvas:image' with image|merge({
  loading: 'eager',  {# For hero images or critical content #}
}) only %}

Responsive sizing

Use the sizes attribute to optimize image loading for different viewport sizes:

{% include 'canvas:image' with image|merge({
  sizes: '(max-width: 480px) 100vw, (max-width: 768px) 50vw, 33vw',
  loading: 'lazy',
}) only %}

Best practices

• Always provide meaningful alt text for accessibility
• Use eager loading only for above-the-fold images
• Specify appropriate sizes for responsive images
• Include width and height to prevent layout shifts