imageConfig vs fileExists workaround

tips & tricks
1

I have concern with the following behaviour of imageConfig vs fileExists and give a workaround:

The issue

TL;DR fileExists looks in the theme’s static directory as well as project root static dir but imageConfig only looks in project root static dir.

Reproducing

Given a file that is in a theme module’s static directory (apple-touch-icon.png), a site in subdirectory of the theme (called exampleSite),

using `replacements` to import the development theme into the site (in a `config.yaml)` 
module:
  replacements: "gitlab.com/danielfdickinson/dfd-hugo-theme-zen -> ../.."
  imports:
    - path: gitlab.com/danielfdickinson/dfd-hugo-theme-zen
      mounts:
        - source: archetypes
          target: archetypes
        - source: assets
          target: assets
        - source: i18n
          target: i18n
        - source: layouts
          target: layouts
        - source: static
          target: static
  mounts:
    - source: assets
      target: assets
    - source: i18n
      target: i18n
    - source: layouts
      target: layouts
    - source: static
      target: static

a site parameter named image with the value `apple-touch-icon.png

The following (condensed version of the real code, originally part of the Zen theme by @frjo) in a partial for <head>:

…
{{ $src := .Param "image" -}}
{{ if and $src (fileExists (path. Join "/static" $src)) -}}
{{ with (imageConfig (path.Join "static" $src)) -}}
  {{ $realwidth .Width -}}
  {{ $realheight .Height -}}
{{ end -}}
…

then hugo v0.111.3-5d4eb5154e1fed125ca8e9b5a0315c4180dab192+extended windows/amd64 BuildDate=2023-03-12T11:40:50Z VendorInfo=gohugoio throws the error:

…
error calling imageConfig: open C:\Users\DanielDickinson\Build\hugo-dfd-sites\dfd-hugo-theme-zen\exampleSite\static\apple-touch-icon.png: The system cannot find the file specified.
…

Workaround

I have created the following workaround for now:

{{ $srcPath := path.Join "/static" $src -}}
{{ $srcDir := path. Dir $srcPath -}}
{{ $dirFiles := readDir $srcDir -}}
{{ $fileInDir := in $dirFiles (path. Base $srcPath) -}}
{{ if and $src (fileExists (path.Join "/static" $src)) $fileInDir -}}
   {{- with (imageConfig (path.Join "static" $src)) -}}
      {{ $realwidth = .Width -}}
      {{ $realheight = .Height -}}
   {{ end -}}
{{ end -}}

which builds without errors and seems to be working as expected.

Questions

@jmooring Is this difference between fileExists and imageConfig (and apparently readDir) expected, or should I create a minimal reproducible test case and file a GitHub bug report?

I’ve run out of time to push the workaround and the version with issues until later tonight, but will do that.

2

I have not taken the time to understand the above, but I guess my first question is, why use fileExists or imageConfig at all?

3

The original code is from shortcodes I have added to the Zen theme.

The reason for using fileExists and imageConfig is to support images in “static”, “assets” as well as page resources. Where ever the user place a image the shortcode will do its best to display it.

1 Like
4

Understood. Personally, I find it easier to mount static to assets and use page or global resources for everything. That eliminates the need for both fileExists and imageConfig.

Additionally, fileExists looks at the OS file system, not Hugo’s virtual file system.