Jekyll - generating JSON files alongside the HTML files

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
# [email protected]
# 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

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.