Sort by first element in front matter slice

[Greg_Kr]

I can’t seem to figure this one out. It might not even be possible in its current form.

I am trying to sort content in my template by the first element of a slice in my content’s front matter.

My content front matter:
—
title: Example
dates:
- 2019-05-30T14:30:00.000Z
- 2019-06-03T11:30:00.000Z
- 2019-06-03T11:30:00.000Z

I can’t seem to figure out how to sort by the first element in the dates slice.

Thanks for any help!

[davidsneighbour]

WHAT are you trying to sort? The three dates or three posts that are indicated by those dates?

Simple sorting would be

{{ range sort .Params.dates }}{{ . }} {{ end }}
{{ range sort .Params.dates "asc" }}{{ . }} {{ end }}
{{ range sort .Params.dates "desc" }}{{ . }} {{ end }}

but I am not sure what exactly you want to sort here.

[Greg_Kr]

Sorry for not being clear.

I am trying to sort all the content (of that type) by the first element of the dates slice.

[davidsneighbour]

There is a function called first that returns the first x slices. Use it with 1 and it should get you the first parameter.

first

The sort function then:

sort

should run as follows (only logic, not working in real life):

{{ range $your-posts $their-first-slice "sortdir" }}

That seems to be quite complicated. I hope someone with more Go knowledge can help.

[Greg_Kr]

I was thinking about that as well, however the sort template function doesn’t support sorting by the provided value but only a key. And unfortunately it is not possible to specify an element of a slice by it’s index in the key.

I have extended hugo to support this, see pull request.