This post contains the more detailed technical planning and how successfull those ideas were.

The Plan

These are the points from the last post that I want to hit with my implementation:

Create a new gallery by adding a folder of pictures.
Support a nested folder/gallery structure.
- Find nested galleries.
- Build a page tree to navigate through galleries.
- Custom thumbnail for each gallery.
Optimize picture files for multiple display sizes.
Allow mixing in some text into the gallery index pages.
Expose everything through jekyll’s layout system.
Allow easy linking to specific pictures from any page across the site.
Provide the same tools for individual pictures attached to pages (rather than being hosted in a full gallery).

Implementation Map

Following the insights from my work leading the last post, this is how I expect the new plugin to work:

setup: a _galleries folder hosting all pictures
generator: load that folder into the site object
generator: build a page tree referencing each of the folders/galleries
code: have a StaticFile equivalent for managing picture rendering on write
generator: add such image file instances for each picture
layout: provide page templates for a gallery and a picture page
let jekyll render everything
???
profit!

Project Start Up

created a new github repo for cheesy-gallery and set up a new gem, travis, codecov, rubocop and dependabot (homepage).
created a new project for cheesy-gallery to capture the even more detailed planning: https://github.com/DavidS/cheesy-gallery/projects/1
Started on building a simple integration test setup with a test site and a quick build step on travis.
Managed to knock out the first programming step on the board, even though I was severly distracted by watching TV :-D

Current status

So the plugin already can correctly recreate the directory structure of the _galleries input folder and use a provided layout. Given my current architectural understanding of jekyll, I’m pretty chuffed to get this done in a (very relaxed) weekend.

The most important insight of this work was realising that - and understanding why - jekyll plugins can’t supply layouts. Initially my expectation was that I could add GalleryPage instances, declare/request a gallery layout and provide a _layouts/gallery.html liquid template in the gem. As it turns out, jekyll has no provisions for this. The key limitation, I believe, is that the gallery.html liquid template would have to link up the the default.html layout from the theme. Since between the user and the theme there is no true “main” template that this could link up to. Is it a page or a default or maybe something completely else? My next though now is that I’ll manually design a layout to render a gallery and a picture page and provide that as an example. At the same time it might be nice to have a set of liquid tags that render a default view and reduce the maintenance amount for site owners. This would also reduce the API surface that I’d need to maintain.

Next steps

As next steps, I’ve planned out list and show images in gallery page and Page Tree Nav with more details of expected implementation.