Matthew Consterdine's

Jekyll is fantastic, easy to use, and extensible. However, some Jekyll hosts such as GitHub Pages do not allow people to use custom plugins - and I want category and year pages. But rightly so. Allowing custom plugins would require hosts to allow users to run arbitrary Ruby code on their build servers and possibly create a mess. This problem is solvable, but it’s ultimately simpler to just ban them entirely.

This constrained environment forces you to get creative. On this blog I use the fantastic jekyll-compress-html template which minifies the very post you are reading. I have written by own template to automatically replace standard markdown or HTML images with lazily loaded ones. And finally, I have written a small (it’s only a hundred or so lines ;) ) Makefile to automatically, among other-things, generate year and category pages:

# Find categories and years
CATTARGETS  = $(shell grep -h '^categories:' -r _posts/ | awk -F ':' \
              '{print $$2}' | tr ' ' '\n' | sed '/^$$/d' | sort | uniq | \
              awk '{print "categories/"$$1".html"}')
YEARTARGETS = $(shell find _posts/ -regextype egrep -regex '.*/[0-9]{4}.[^/]*' \
              -printf '%P\n' | cut -c-4 | sort | uniq | \
              awk '{print "years/"$$1".html"}')

# Generate category pages
cat: cat-clean $(CATTARGETS)
categories/%.html: _templates/category.html
	cp $< $@
	sed -i 's/#####CATEGORY#####/$*/' $@

# Generate year pages
year: year-clean $(YEARTARGETS)
years/%.html: _templates/year.html
	cp $< $@
	sed -i 's/#####YEAR#####/$*/' $@

To use, simply create _templates/category.html and a _templates/year.html templates and run make cat year. The code assumes your posts start with the date and they are stored in the default _posts/. When run #####CATEGORY##### and #####YEAR##### will be replaced with the templated value.