画像の縦横比と遅延読み込み

{% liquid
  # theme-check-disable ImgLazyLoading 
  # theme-check-disable RemoteAsset
%}

{% comment %}
  Renders an image tag throught the Shopify's, image_url filter
  https://shopify.dev/docs/api/liquid/filters/image_url

  Accepts:
  - img: {object} The image object to apply the filter
  - size: {Number} (Optional) The preferred image size which the image width/height will be handled. (default is 600)
  - orientation: {String} (Optional) The image orientation. (default is square)
  - loading {String} {Optional} The image loading mode. Either lazy or eager. (default is lazy)
  - scale {Boolean} {Optional}. Useful if your images are looking blurred. (default is false)
  - class: {String} (Optional) An optional class to apply to the Img element

  Usage:
  {% render 'image-url' img: product.featured_image, size: 600, orientation: 'square', loading: 'lazy', scale: false, class: "mb-4"  %}
{% endcomment %}

{% liquid
  assign size = size | default: 600
  assign orientation = orientation | default: 'square'
  assign loading = loading | default: 'lazy'

  case orientation
    when 'ratio-1x1'
      assign width = size
      assign height = size 
    when 'ratio-4x3'
      assign width = size
      assign height = size | divided_by: 4 | times: 3 | round
    when 'ratio-16x9'
      assign width = size
      assign height = size | divided_by: 16 | times: 9 | round
      when 'ratio-21x9'
      assign width = size
      assign height = size | divided_by: 21 | times: 9 | round
    when 'ratio-3x4'
      assign width = size | divided_by: 4 | times: 3 | round
      assign height = size
    when 'ratio-9x16'
      assign width = size | divided_by: 16 | times: 9 | round
      assign height = size
    when 'ratio-9x21'
      assign width = size | divided_by: 21 | times: 9 | round
      assign height = size
    else
      assign width  = size
      assign height = size | divided_by: img.aspect_ratio | round
  endcase

  if scale
    assign width_scaled = width | times: 2
    assign height_scaled = height | times: 2
  else
    assign width_scaled = width
    assign height_scaled = height
  endif
%}

<img
  src="{{ img | image_url: width: width_scaled, height: height_scaled, crop: 'center' }}"
  class="img-fluid {{ class }}"
  alt="{{ img.alt }}"
  width="{{ width }}"
  height="{{ height }}"
  loading="{{ loading }}">

{% liquid
  # theme-check-enable ImgLazyLoading 
  # theme-check-enable RemoteAsset
%}