support an array for collections frontmatter key

[thescientist13]

Type of Change

Enhancement

Summary

Currently, Greenwood supports defining content collections through a frontmatter key

---
collection: navigation
order: 2
---

# About Page

Lorum Ipsum

However, it was observed / requested that content could belong in more than one collection, so allowing it be an array would be really nice.

---
collection:
  - navigation
  - other
order: 2
---

# About Page

Lorum Ipsum

Details

Aside from implementing this, would also want to update the documentation to demonstrate this capability / option.

[lschierer]

This would fill a significant hole in mirroring the PageSpec functionality of ikiwiki. I have a very old install of that I used heavily from about 2005 to 2018 that I recently needed to adjust something on, and last night I briefly looked at what it would take to move it to a platform more consistent with everything else that I'm now doing.

[thescientist13]

Great, thanks for sharing your case that is definitely helpful.

Let me queue this up for the next release line (0.32.0), and can probably get it out in an alpha at least in the next couple of weeks.

[lschierer]

to elaborate slightly, since I had configured ikiwiki to use git for dates anyway, by running some slightly scary find | sed commands across the repository, I can change a bunch of ikiwiki meta tags to frontmatter fields with reasonable levels of manual intervention despite just about 3k files. From there I can use the info in git's metadata, the compilation, and content-by-route to replace nearly everything except the matching on tags. While I could probably reimplement that with custom front matter, the collections (with getContentByCollection already existng) are filling very nearly the same role as the way ikiwiki used tags.

there's lots of things that ikiwiki plugins could do that would still require custom development work, but I wasn't using many plugins that do much except enforce good behavior (on either my part as the author or on the tool's part in the form of output). So this isn't a generic conversion solution, but I think that's one of the things I like about both Greenwood and Ikiwiki - there's lots of room for personal use cases.