feat: add responsive image support (#1283)

* feat: create responsive-image helper

* feat: new responsive-image helper

* feat: Implement responsive image rendering in page content using a new partial and configure image processing widths.

* feat: add `sizes` attribute for enhanced image responsiveness

* feat: add responsive image to page header too

* Check for `.Enabled` before processing image

* style: remove wrong article-list--tile width and height

* feat: add `helper/thumbnail-image` for responsive thumbnails

* feat: enable content image processing and update responsive image `sizes` attributes for improved display.

* fix: get src from the attributes so external image can work correctly

* fix: add missing data-title-escaped

* Update layouts/_partials/article/components/header.html

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* feat: remove default `true` for thumbnail resize parameter.

* Update layouts/_markup/render-image.html

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update layouts/_partials/helper/thumbnail-image.html

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* add original width and height to thumbnail pictures, for case that resize is not enabled

* Update layouts/_partials/helper/thumbnail-image.html

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

assets/scss/partials/article.scss

@@ -207,8 +207,8 @@
         border-radius: var(--card-border-radius);
         overflow: hidden;
         position: relative;
-        height: 350px;
         width: 250px;
+        height: 150px;
         box-shadow: var(--shadow-l1);
         transition: box-shadow 0.3s ease;
         background-color: var(--card-background);

assets/scss/partials/layout/article.scss

@@ -242,8 +242,6 @@
         margin-right: 15px;
         flex-shrink: 0;
         overflow: hidden;
-        width: 250px;
-        height: 150px;
 
         .article-title {
             font-size: 1.8rem;

assets/scss/partials/layout/list.scss

@@ -56,8 +56,6 @@
         width: max-content;
 
         article {
-            width: 250px;
-            height: 150px;
             margin-right: 20px;
             flex-shrink: 0;
 

config/_default/params.toml

@@ -75,10 +75,12 @@ SortBy             = "default"
     toggle  = true
     default = "auto"
 
-[imageProcessing.cover]
+[imageProcessing]
+    [imageProcessing.content]
+        widths  = [800, 1600, 2400]
         enabled = true
 
-[imageProcessing.content]
+    [imageProcessing.thumbnail]
         enabled = true
 
 # GDPR Cookie Consent Configuration

layouts/_markup/render-image.html

@@ -2,23 +2,29 @@
 {{- $alt := .PlainText | safeHTML -}}
 {{- $title := .Title | markdownify -}}
 
-{{/* SVG and external images won't work with gallery layout, because their width and height attributes are unknown */}}
+{{/* There are some types of images that don't have width and height attributes, such as SVG */}}
 {{- $galleryImage := and $image.Height $image.Width -}}
 
-<img src="{{ $image.Permalink }}"
+{{- $attributes := dict -}}
-	{{ with $image.Width }}width="{{ . }}"{{ end }}
+{{- if $galleryImage -}}
-	{{ with $image.Height }}height="{{ . }}"{{ end }}
+    {{- $attributes = (dict 
-	loading="lazy"
+        "data-flex-grow" (div (mul $image.Width 100) $image.Height) 
-	{{ with $alt }}
+        "data-flex-basis" (printf "%dpx" (div (mul $image.Width 240) $image.Height))
-		alt="{{ . }}"
+    ) -}}
-	{{ end }}
+{{- end -}}
-    {{ with $title }}
+
-        title="{{ . }}"
+{{ partial "helper/responsive-image" (dict 
-        data-title-escaped="{{ . | htmlEscape }}"
+    "Resource" $image.Resource
-    {{ end }}
+    "Widths" (cond .Page.Site.Params.ImageProcessing.Content.Enabled .Page.Site.Params.ImageProcessing.Content.Widths nil)
-	{{ if $galleryImage }}
+    "Attributes" (merge $attributes (dict 
-		class="gallery-image" 
+        "src" $image.Permalink
-		data-flex-grow="{{ div (mul $image.Width 100) $image.Height }}"
+        "width" $image.Width
-		data-flex-basis="{{ div (mul $image.Width 240) $image.Height }}px"
+        "height" $image.Height
-	{{ end }}
+        "alt" $alt
->
+        "title" $title
+        "data-title-escaped" ($title | htmlEscape)
+        "class" (cond $galleryImage "gallery-image" "")
+        "loading" "lazy"
+        "sizes" "(max-width: 767px) calc(100vw - 30px), (max-width: 1023px) 700px, (max-width: 1279px) 950px, 1232px"
+    ))
+) }}

layouts/_partials/article-list/compact.html

@@ -14,8 +14,19 @@
         {{- $image := partial "helper/image" (dict "Image" .Params.image "Resources" .Resources) -}}
         {{ if $image }}
         <div class="article-image">
-            <img src="{{ $image.Permalink }}" width="{{ $image.Width }}" height="{{ $image.Height }}" alt="{{ .Title }}"
+            {{ partial "helper/thumbnail-image" (dict 
-                loading="lazy">
+                "Resource" $image.Resource
+                "Width" 60
+                "Height" 60
+                "Resize" .Site.Params.ImageProcessing.Thumbnail.Enabled
+                "Attributes" (dict
+                    "src" $image.Permalink
+                    "alt" .Title
+                    "loading" "lazy"
+                    "width" $image.Width
+                    "height" $image.Height
+                )
+            ) }}
         </div>
         {{ end }}
     </a>

layouts/_partials/article-list/tile.html

@@ -3,8 +3,19 @@
     <a href="{{ .context.RelPermalink }}">
         {{ if $image }}
         <div class="article-image">
-            <img src="{{ $image.Permalink }}" width="{{ $image.Width }}" height="{{ $image.Height }}" loading="lazy"
+            {{ partial "helper/thumbnail-image" (dict 
-                alt="Featured image of post {{ .context.Title }}">
+                "Resource" $image.Resource
+                "Width" 250
+                "Height" 150
+                "Resize" .context.Site.Params.ImageProcessing.Thumbnail.Enabled
+                "Attributes" (dict
+                    "src" $image.Permalink
+                    "alt" (printf "Featured image of post %s" .context.Title)
+                    "loading" "lazy"
+                    "width" $image.Width
+                    "height" $image.Height
+                )
+            ) }}
         </div>
         {{ end }}
 

layouts/_partials/article/components/header.html

@@ -5,8 +5,18 @@
     {{ if $image }}
     <div class="article-image">
         <a href="{{ $Page.RelPermalink }}">
-            <img src="{{ $image.Permalink }}" width="{{ $image.Width }}" height="{{ $image.Height }}" loading="lazy"
+            {{ partial "helper/responsive-image" (dict
-                alt="Featured image of post {{ $Page.Title }}" />
+                "Resource" $image.Resource
+                "Widths" (cond $Page.Site.Params.ImageProcessing.Content.Enabled $Page.Site.Params.ImageProcessing.Content.Widths nil)
+                "Attributes" (dict
+                    "src" $image.Permalink
+                    "width" $image.Width
+                    "height" $image.Height
+                    "alt" (printf "Featured image of post %s" $Page.Title)
+                    "loading" "lazy"
+                    "sizes" "(max-width: 767px) calc(100vw - 30px), (max-width: 1023px) 700px, (max-width: 1279px) 950px, 1232px"
+                )
+            ) }}
         </a>
     </div>
     {{ end }}

layouts/_partials/helper/responsive-image.html

@@ -0,0 +1,33 @@
+{{- /*
+Params:
+    Resource: Hugo image resource object (Optional, for processing)
+    Widths: Slice of widths to generate for srcset
+    Attributes: Map of HTML attributes for the <img> tag
+*/ -}}
+
+{{- $resource := .Resource -}}
+{{- $widths := .Widths -}}
+{{- $attributes := .Attributes | default dict -}}
+
+{{/* Generate srcset if Resource and Widths are provided */}}
+{{- if and $widths $resource (reflect.IsImageResourceProcessable $resource) -}}
+    {{- $srcset := slice -}}
+    {{- range $widths -}}
+        {{- if lt . $resource.Width -}}
+            {{- $resized := $resource.Resize (printf "%dx" .) -}}
+            {{- $srcset = $srcset | append (printf "%s %dw" $resized.RelPermalink .) -}}
+        {{- end -}}
+    {{- end -}}
+    
+    {{- if gt (len $srcset) 0 -}}
+        {{- $permalink := default $resource.RelPermalink (index $attributes "src") -}}
+        {{- $srcset = $srcset | append (printf "%s %dw" $permalink $resource.Width) -}}
+        {{- $attributes = merge $attributes (dict "srcset" (delimit $srcset ", ")) -}}
+    {{- end -}}
+{{- end -}}
+
+<img {{- range $k, $v := $attributes -}}
+    {{- if $v -}}
+        {{- printf " %s=%q" (lower $k) (printf "%v" $v) | safeHTMLAttr -}}
+    {{- end -}}
+{{- end -}}>

layouts/_partials/helper/thumbnail-image.html

@@ -0,0 +1,41 @@
+{{- /*
+Params:
+    Resource: Hugo image resource object (Optional, for processing)
+    Width: Image width (Required)
+    Height: Image height (Required)
+    Resize: Whether to perform resize (Optional, default: false)
+    Attributes: Map of HTML attributes for the <img> tag
+*/ -}}
+
+{{- $resource := .Resource -}}
+{{- $width := .Width -}}
+{{- $height := .Height -}}
+{{- $resize := .Resize -}}
+{{- $attributes := .Attributes | default dict -}}
+
+{{- if and $resize $resource (reflect.IsImageResourceProcessable $resource) $width $height -}}
+    {{/* Create thumbnail with 1x/2x descriptors */}}
+    {{- $srcset := slice -}}
+    {{- range (slice 1 2) -}}
+        {{- $w := mul $width . -}}
+        {{- $h := mul $height . -}}
+        {{- if and (le $w $resource.Width) (le $h $resource.Height) -}}
+            {{- $resized := $resource.Fill (printf "%dx%d" $w $h) -}}
+            {{- $srcset = $srcset | append (printf "%s %dx" $resized.RelPermalink .) -}}
+            
+            {{- if eq . 1 -}}
+                {{- $attributes = merge $attributes (dict "src" $resized.RelPermalink) -}}
+            {{- end -}}
+        {{- end -}}
+    {{- end -}}
+    
+    {{- if gt (len $srcset) 0 -}}
+        {{- $attributes = merge $attributes (dict "width" $width "height" $height "srcset" (delimit $srcset ", ")) -}}
+    {{- end -}}
+{{- end -}}
+
+<img {{- range $k, $v := $attributes -}}
+    {{- if $v -}}
+        {{- printf " %s=%q" (lower $k) (printf "%v" $v) | safeHTMLAttr -}}
+    {{- end -}}
+{{- end -}}>