Jekyll - generating JSON files alongside the HTML files - ruby

Question

I'd like to make Jekyll create an HTML file and a JSON file for each page and post. This is to offer a JSON API of my Jekyll blog - e.g. a post can be accessed either at /posts/2012/01/01/my-post.html or /posts/2012/01/01/my-post.json
Does anyone know if there's a Jekyll plugin, or how I would begin to write such a plugin, to generate two sets of files side-by-side?

Answer 1

I was looking for something like this too, so I learned a bit of ruby and made a script that generates JSON representations of Jekyll blog posts. I’m still working on it, but most of it is there.
I put this together with Gruntjs, Sass, Backbonejs, Requirejs and Coffeescript. If you like, you can take a look at my jekyll-backbone project on Github.
# encoding: utf-8
#
# Title:
# ======
# Jekyll to JSON Generator
#
# Description:
# ============
# A plugin for generating JSON representations of your
# site content for easy use with JS MVC frameworks like Backbone.
#
# Author:
# ======
# Jezen Thomas
# jezenthomas#gmail.com
# http://jezenthomas.com
module Jekyll
require 'json'
class JSONGenerator < Generator
safe true
priority :low
def generate(site)
# Converter for .md > .html
converter = site.getConverterImpl(Jekyll::Converters::Markdown)
# Iterate over all posts
site.posts.each do |post|
# Encode the HTML to JSON
hash = { "content" => converter.convert(post.content)}
title = post.title.downcase.tr(' ', '-').delete("’!")
# Start building the path
path = "_site/dist/"
# Add categories to path if they exist
if (post.data['categories'].class == String)
path << post.data['categories'].tr(' ', '/')
elsif (post.data['categories'].class == Array)
path << post.data['categories'].join('/')
end
# Add the sanitized post title to complete the path
path << "/#{title}"
# Create the directories from the path
FileUtils.mkpath(path) unless File.exists?(path)
# Create the JSON file and inject the data
f = File.new("#{path}/raw.json", "w+")
f.puts JSON.generate(hash)
end
end
end
end

Answer 2

There are two ways you can accomplish this, depending on your needs. If you want to use a layout to accomplish the task, then you want to use a Generator. You would loop through each page of your site and generate a new .json version of the page. You could optionally make which pages get generated conditional upon the site.config or the presence of a variable in the YAML front matter of the pages. Jekyll uses a generator to handle slicing blog posts up into indices with a given number of posts per page.
The second way is to use a Converter (same link, scroll down). The converter will allow you to execute arbitrary code on your content to translate it to a different format. For an example of how this works, check out the markdown converter that comes with Jekyll.
I think this is a cool idea!

Answer 3

Take a look at JekyllBot and the following code.
require 'json'
module Jekyll
class JSONPostGenerator < Generator
safe true
def generate(site)
site.posts.each do |post|
render_json(post,site)
end
site.pages.each do |page|
render_json(page,site)
end
end
def render_json(post, site)
#add `json: false` to YAML to prevent JSONification
if post.data.has_key? "json" and !post.data["json"]
return
end
path = post.destination( site.source )
#only act on post/pages index in /index.html
return if /\/index\.html$/.match(path).nil?
#change file path
path['/index.html'] = '.json'
#render post using no template(s)
post.render( {}, site.site_payload)
#prepare output for JSON
post.data["related_posts"] = related_posts(post,site)
output = post.to_liquid
output["next"] = output["next"].id unless output["next"].nil?
output["previous"] = output["previous"].id unless output["previous"].nil?
#write
#todo, figure out how to overwrite post.destination
#so we can just use post.write
FileUtils.mkdir_p(File.dirname(path))
File.open(path, 'w') do |f|
f.write(output.to_json)
end
end
def related_posts(post, site)
related = []
return related unless post.instance_of?(Post)
post.related_posts(site.posts).each do |post|
related.push :url => post.url, :id => post.id, :title => post.to_liquid["title"]
end
related
end
end
end
Both should do exactly what you want.