update layouts

layouts/partials/lazyimg.html

@@ -0,0 +1,61 @@
+{{/* Parameter Parsing */}}
+{{ $usage := `lazyimg:
+    Usage like:
+    - {{ partial "lazyimg" "image.jpg" }}
+    - {{ partial "lazyimg" (resources.Get "image.jpg") }}
+
+    ...or more verbose by specifying a dict overriding the site.Params.lazyimg, e.g.:
+    - {{ partial "lazyimg" (dict "resizer" "auto" "renderer" "lqip") }}
+    - {{ partial "lazyimg" (dict "img" "image.jpg" "responsiveSizes" (slice "320px" "640px") "resizer" "responsive") }}
+
+    Please ensure that image exists in ./assets directory.
+` }}
+
+{{/* Parse and normalize input parameters: */}}
+{{ $params := merge site.Params.lazyimg (dict 
+    "img" . 
+    "resizer" (default "responsive" site.Params.lazyimg.resizer) 
+    "renderer" (default "lqip" site.Params.lazyimg.renderer)
+)}}
+{{ if reflect.IsMap . }}
+    {{ $userParams := dict }}
+    {{/* Normalize by transforming all keys to lower-case: */}}
+    {{ range $k, $v := . -}}
+        {{ $userParams = $userParams | merge (dict (lower $k) $v) }}
+    {{- end -}}
+    {{ $params = merge $params $userParams }}
+{{ end }}
+
+{{/* Attempt to load image resource: */}}
+{{ $resType := (printf "%T" $params.img) }}
+{{ $resLoaded := in $resType "resource" }}
+{{ if not $resLoaded }}
+    {{ with $res := resources.Get $params.img }}
+        {{ $params = merge $params (dict "img" $res) }}
+        {{ $resLoaded = true }}
+    {{ end }}
+{{ end }}
+
+{{/* Handle error if not loaded yet: */}}
+{{ if not $resLoaded }}
+    {{/* Try if error-handler is able to resolve it */}}
+    {{ $params = partial (printf "error-handler/%s" site.Params.lazyimg.errorHandler) $params }}
+    {{ if $params }}
+        {{ $resLoaded = in (printf "%T" $params.img) "resource" }}
+    {{ end }}
+{{ end }}
+{{/* Only proceed if resource has been loaded: */}}
+{{ if $resLoaded }}
+    {{/* Special handling for WebP renderers: */}}
+    {{ if in $params.renderer "webp" }}
+        {{/* Override user-supplied target format */}}
+        {{ $resizeOptionsWebP := printf "%s webp" ($params.resizeoptions | replaceRE "(jpg|png|tif|bmp|gif)" "") }}
+        {{ $paramsWebP := merge $params (dict "resizeoptions" $resizeOptionsWebP) }}
+        {{ $imagesWebP := partial (printf "resizer/%s" $params.resizer) $paramsWebP }}
+        {{ $imagesRegular := partial (printf "resizer/%s" $params.resizer) $params }}
+        {{ partial (printf "renderer/%s" $params.renderer) (merge $params (dict "imgDict" $imagesWebP "imgDictFallback" $imagesRegular)) }}
+    {{ else }}
+        {{ $sizes := partial (printf "resizer/%s" $params.resizer) $params }}
+        {{ partial (printf "renderer/%s" $params.renderer) (merge $params (dict "imgDict" $sizes)) }}
+    {{ end }}
+{{ end }}