Hugo - using index with complex key to get data

Question

Assuming the following urls.toml file in data folder:

[Group]
    link = "http://example.com"
    [Group.A]
        link = "http://example.com"

I know that I can access the link value in Group.A in my shortcode like this:

{{ index .Site.Data.urls.Group.A "link" }}

But, I would like to access the link in a way similar to the following:

{{ index .Site.Data.urls "Group.A.link" }}

The reason for this is to enable me to pass the "Group.A.link" as a parameter to my "url" shortcode within the content markdown like this:

{{< url "Group.A.link" >}}

Otherwise, I won't be able to use nesting for logical organisation in the urls.toml data file.

Thanks in advance.

Answer 1

After having looked at Hugo's code (Index function) I found a very simple solution. If we want to pass a complex comma-separated key, all we need to do is split it when calling index. Example:

Using the url shortcode in markdown:

{{< url "Group.A.link" >}}

Code of the url shortcode:

{{ index .Site.Data.urls (split (.Get 0) ".")}}

Answer 2

You can use nested calls of index COLLECTION "key" to narrow your way down.
Meaning,

(index (index (index .Site.Data.urls "Group") "A") "link")

would work given your urls.toml structure.

The trick is making it somewhat dynamic, so you don't need to worry too much about depth.

The snippet below might serve as a potential starting point for a shortcode. However, it doesn't have any safe-guards. I'd recommend to add a few checks to get meaningful errors/warnings if things go wrong.

{{ $path := .Get 0 }}
{{/* split the string to have indices to follow the path */}}
{{/* if $path is "A.B.C", $pathSlice wil be ["A" "B" "C"] */}}
{{ $pathSlice := split $path "." }}
{{ $currentValue := .Site.Data.urls }}
{{ range $pathSlice }}
    {{/* recommended homework: check that $currentValue is a dict otherwise handle with defaults and/or warnings */}}
    {{ $currentValue = index $currentValue . }}
{{ end }}

<p>et voila: {{ $currentValue }}</p>