Two versions of each blog post in Jekyll - ruby

I need two versions of each of my posts in a very simple Jekyll setup: The public facing version and a barebones version with branding specifically for embedding.
I have one layout for each type:
post.html
post_embed.html
I could accomplish this just fine by making duplicates of each post file with different layouts in the front matter, but that's obviously a terrible way to do it. There must be a simpler solution, either at the level of the command line or in the front matter?
Update:
This SO question covers creating JSON files for each post. I really just need a generator to loop through each post, alter one value in the YAML front matter (embed_page=True) and feed it back to the same template. So each post is rendered twice, once with embed_page true and one with it false. Still don't have a full grasp of generators.

Here's my Jekyll plugin to accomplish this. It's probably absurdly inefficient, but I've been writing in Ruby for all of two days.
module Jekyll
# override write and destination functions to taking optional argument for pagename
class Post
def destination(dest, pagename)
# The url needs to be unescaped in order to preserve the correct filename
path = File.join(dest, CGI.unescape(self.url))
path = File.join(path, pagename) if template[/\.html$/].nil?
path
end
def write(dest, pagename="index.html")
path = destination(dest, pagename)
puts path
FileUtils.mkdir_p(File.dirname(path))
File.open(path, 'w') do |f|
f.write(self.output)
end
end
end
# the cleanup function was erasing our work
class Site
def cleanup
end
end
class EmbedPostGenerator < Generator
safe true
priority :low
def generate(site)
site.posts.each do |post|
if post.data["embeddable"]
post.data["is_embed"] = true
post.render(site.layouts, site.site_payload)
post.write(site.dest, "embed.html")
post.data["is_embed"] = false
end
end
end
end
end

Related

Ruby encapsulate/package existing code into a namespace

I've been looking all around and didn't found any kind of answer to the problem i'm facing in Ruby. I'm writing an app that use core modules sets that are available in different versions. If I'm sourcing a core set version after an another one both code version will be sourced at the same and will clash with each other. That is quite normal and I'm ok with this.
One approach could be to unload the previous version to load the new one but I'd like to keep all the ones loaded into specific namespaces (to avoid time consuming to unload/reload code all the time). 2 possible solutions to me (or maybe other)
Either source the code then move it into a version namespace (some clues to do it see below but doesn't work yet)
Or source the code directly into a version namespace (don't know how to do it exactly, maybe with module_eval but need to recode the require process with dependencies). Does any solution seems possible ?
Here is a very simple poc of what I'm trying to achieve
file : coreset_1.0.0.rb
module CoreA
def self.who_am_i?; self.to_s; end
def self.get_coreb; CoreB end
end
module CoreB
def self.who_am_i?; self.to_s; end
end
file : coreset_2.0.0.rb (got some changes)
module CoreA
def self.my_name; self.to_s; end
def self.get_coreb; CoreB end
end
module CoreB
def self.my_name; self.to_s; end
end
file : coreManager.rb
module CoreManager
def self.load_version(arg_version)
#Create a module set for the selected version
core_set_name = CoreSet + '_' + arg_version.gsub('.', '_')
core_set = eval("Module #{core_set_name}; end; #{core_set_name}"
#Load the requested code
require "coreset_#{arg_version}.rb"
#Move loaded code into it core set module
core_set.const_set(:CoreA, Object.send(:remove_const, :CoreA))
core_set.const_set(:CoreB, Object.send(:remove_const,:CoreB))
#Return the created core set
core_set
end
end
If running the code :
require 'coreManager.rb'
core_set = CoreManager.load_version("1.0.0")
puts core_set::CoreA.who_am_i?
puts core_set::CoreA.get_coreB
it returns :
CoreA #not CoreSet_1_0_0::CoreA
uninitialized constant CoreA::CoreB (NameError)
If running something statically defined, it works
module CoreSet
module CoreA
def self.who_am_i?; self.to_s; end
def self.get_coreb; CoreB end
end
module CoreB
def self.who_am_i?; self.to_s; end
end
end
CoreSet::CoreA.get_coreb
It returns as expected :
CoreSet::CoreB
Depite of what is usually said :"a module is a constant", it seems to be more than that. What are the differencies and how to make the dynamic version working ?
Any other ideas ?
Thanks for your help folks :)
There are several things broken in your code (which is ok for POC, I guess), but the main one is that require loads constants and globals into the global namespace.
So, your Core<X> modules are not namespaced this way, as you might expect. There is Kernel#load method that allows "wrapped" execution of the loaded file, but it's wrapped into an anonymous module, so you can prevent the global namespace from being polluted, but you cannot "target" the constants to be defined into a particular namespace this way.
What you could try is to load the code as text and then eval it within the dynamically created module, matching your version. For example, look at this quick and very dirty sketch (coreset_...rb files are expected to sit into coresets directory):
module CoreSet; end
class CoreManager
class << self
def load_version(ver)
raise "Vesion #{ver} unknown" unless exists?(ver)
file = filename(ver)
code = File.read(file)
versioned_wrapper = Module.new do
class_eval code
end
CoreSet.const_set("V_#{ver.gsub('.', '_')}", versioned_wrapper)
end
private
def exists?(ver)
File.exists? filename(ver)
end
def filename(ver)
"coresets/coreset_#{ver.gsub('.', '_')}.rb"
end
end
end
CoreManager.load_version("1.0.0")
CoreManager.load_version("2.0.0")
p CoreSet::V_1_0_0::CoreA.who_am_i? # => "CoreSet::V_1_0_0::CoreA"
p CoreSet::V_1_0_0::CoreA.get_coreb # => CoreSet::V_1_0_0::CoreB
p CoreSet::V_2_0_0::CoreA.my_name # => "CoreSet::V_2_0_0::CoreA"
p CoreSet::V_2_0_0::CoreA.get_coreb # => CoreSet::V_2_0_0::CoreB
But, DON'T do this at home, please :) At least, I would think twice.
If all you need is to have all the versions loaded at once (you need namespaces exactly for this, right?) what stops you from defining them statically, like CoreSet::V1::Core<X> etc and use the idiomatic and safe ways to (auto)load them? :) Playing with dynamic nested constants definition (and, especially, their removing) is one of the easiest ways to shoot your own foot...
Ok I finally came to a solution that may help others or that can be discussed.
Getting the error uninitialized constant CoreA::CoreB (NameError) leads me to take the problem under a new angle. If I'm not able to access to CoreB module from CoreA (because the module nesting has been broken when redefining module constants into the CoreSet module) then why not referencing in each core module the other ones in the set ? And finaly it works without any dirty hack, I'm just creating pointers and the Ruby Core find it natively ;)
module CoreManager
def self.load_version(arg_version)
#Create a module set for the selected version
core_set_name = CoreSet + '_' + arg_version.gsub('.', '_')
core_set = eval("Module #{core_set_name}; end; #{core_set_name}"
#Load the requested code
toplevel_consts = Object.constants
require "coreset_#{arg_version}.rb"
core_modules = Object.constants - toplevel_consts
#Move the core modules to the set namespace
core_modules.collect! do |core_module|
core_module_sym = core_module.to_s.to_sym
core_set.const_set(core_module_sym, Object.send(:remove_const, core_module_sym))
eval("#{core_set}::#{core_module}")
end
#Create connexion between set cores to skirt broken module nesting
core_modules.each do |current_core|
core_modules.each do |other_core|
current_core.const_set(other_core.to_s.to_sym, other_core) unless current_core == other_core
end
end
#Return the created core set
core_set
end
end

Calling one jekyll plugin from another

I'm writing a jekyll plugin to create a custom tag. It takes an argument and spits out a string of HTML. I've got it mostly working - I can pass it arguments and get back HTML based on those arguments. Great.
Here's what has me stumped: I want to include the render of another plugin as part of my own.
My aspirational plugin is jekyll_icon_list, the plugin I want to use is jekyll-inline-svg. Here's the (abbreviated) code:
require 'jekyll_icon_list/version'
require 'jekyll'
require 'jekyll-inline-svg'
module JekyllIconList
class IconList < Liquid::Tag
def initialize(tag_name, raw_args, tokens)
#raw_args = raw_args
#tokens = tokens
super
end
def parse_arguments(raw_args, settings)
# (Unrelated stuff)
end
def generate_image(icon, settings, context)
# (Unrelated stuff)
# Problem Here:
Liquid::Tag.parse(
'svg',
icon,
#tokens,
Liquid::ParseContext.new
).render(context)
end
def render(context)
# Builds my HTML, using generate_image in the process
end
end
end
Liquid::Template.register_tag('iconlist', JekyllIconList::IconList)
This doesn't throw any errors, but it also doesn't return anything at all.
Other things I've tried:
Jekyll::Tags::JekylInlineSvg.new(
returns a private method error. Jekyll doesn't want me making my own tags directly.
'{% svg #{icon} %}'
Returns exactly that literally with the icon substituted in; jekyll clearly doesn't parse the same file twice.
I'm trying to figure it out from Jekyll's source, but I'm not so practiced at reading source code and keep hitting dead ends. Can anyone point me in the right direction? Much appreciated.
Answering my own question:
def build_svg(icon_filename)
tag = "{% svg #{icon_filename} %}"
liquid_parse(tag)
end
def liquid_parse(input)
Liquid::Template.parse(input).render(#context)
end
Basically create a tiny template consisting of the tag you want to call, and hand it off to Liquid for parsing.
Below is the dirty way, which I used before I found the proper way:
Jekyll::Tags::JekyllInlineSvg.send(:new, 'svg', icon_filename, #tokens).render(context)
I found this question and answer, and while it's correct, I wanted to provide a full end-to-end example.
I wanted to wrap Jekyll Scholar's {% cite %} tags in my own content:
module Jekyll
class RenderTimeTag < Liquid::Tag
def initialize(tag_name, text, tokens)
super
#text = text
end
def build_cite(content, context)
tag = "{% cite #{content} %}"
return liquid_parse(tag, context)
end
def liquid_parse(input, context)
template = Liquid::Template.parse(input)
template.render(context)
end
def render(context)
citation = build_cite(#text, context)
# Yeah, I know this is bad HTML:
"<span tabindex=\"0\" class=\"citeblock\">#{citation}</span>"
end
end
end
Liquid::Template.register_tag('pretty_cite', Jekyll::RenderTimeTag)

Preprocessing markup files in jekyll

I would like to write a preprocessor that operates on a range of markup languages before they're processed into HTML by Jekyll. Ideally the user would simply create a file called _posts/xxyyzz.md.wmd, and Jekyll would preprocess it into xxyyzz.md using a plugin I provide, and then process that into HTML in the usual way.
It looks like Jekyll's Converter framework doesn't allow that, because the output_ext function is only given the final extension "wmd", preventing it from returning ".md" for ".md.wmd", ".textile" for ".textile.wmd", etc.
Is there a way to implement a chain of processing steps like this?
EDIT: grammar
Maybe you can try to use a Generator plugin that uses your wmd converter:
require "yourWmdConverter"
module Jekyll
class ConvertWmd < Jekyll::Generator
def initialize(config)
config['convert_wmd'] ||= true
end
def generate(site)
#site = site
site.posts.docs.each { |post| convertWmd post }
end
private
def convertWmd(post)
post.content = yourWmdConverter post.content
end
end
end

read json in Ruby and set variables for use in another class

The need here is to read a json file and to make the variables which is done from one class and use them with in another class. What I have so far is
helper.rb
class MAGEINSTALLER_Helper
#note nonrelated items removed
require 'fileutils'
#REFACTOR THIS LATER
def load_settings()
require 'json'
file = File.open("scripts/installer_settings.json", "rb")
contents = file.read
file.close
#note this should be changed for a better content check.. ie:valid json
#so it's a hack for now
if contents.length > 5
begin
parsed = JSON.parse(contents)
rescue SystemCallError
puts "must redo the settings file"
else
puts parsed['bs_mode']
parsed.each do |key, value|
puts "#{key}=>#{value}"
instance_variable_set("#" + key, value) #better way?
end
end
else
puts "must redo the settings file"
end
end
#a method to provide feedback simply
def download(from,to)
puts "completed download for #{from}\n"
end
end
Which is called in a file of Pre_start.rb
class Pre_start
#note nonrelated items removed
def initialize(params=nil)
puts 'World'
mi_h = MAGEINSTALLER_Helper.new
mi_h.load_settings()
bs_MAGEversion=instance_variable_get("#bs_MAGEversion") #doesn't seem to work
file="www/depo/newfile-#{bs_MAGEversion}.tar.gz"
if !File.exist?(file)
mi_h.download("http://www.dom.com/#{bs_MAGEversion}/file-#{bs_MAGEversion}.tar.gz",file)
else
puts "mage package exists"
end
end
end
the josn file is valid json and is a simple object (note there is more just showing the relevant)
{
"bs_mode":"lite",
"bs_MAGEversion":"1.8.0.0"
}
The reason I need to have a json settings file is that I will need to pull settings from a bash script and later a php script. This file is the common thread that is used to pass settings each share and need to match.
Right now I end up with an empty string for the value.
The instance_variable_setis creating the variable inside MAGEINSTALLER_Helper class. That's the reason why you can't access these variables.
You can refactor it into a module, like this:
require 'fileutils'
require 'json'
module MAGEINSTALLER_Helper
#note nonrelated items removed
#REFACTOR THIS LATER
def load_settings()
content = begin
JSON.load_file('scripts/installer_settings.json')
rescue
puts 'must redo the settings file'
{} # return an empty Hash object
end
parsed.each {|key, value| instance_variable_set("##{key}", value)}
end
#a method to provide feedback simply
def download(from,to)
puts "completed download for #{from}\n"
end
end
class PreStart
include MAGEINSTALLER_Helper
#note nonrelated items removed
def initialize(params=nil)
puts 'World'
load_settings # The method is available inside the class
file="www/depo/newfile-#{#bs_MAGEversion}.tar.gz"
if !File.exist?(file)
download("http://www.dom.com/#{#bs_MAGEversion}/file-#{#bs_MAGEversion}.tar.gz",file)
else
puts "mage package exists"
end
end
end
I refactored a little bit to more Rubish style.
On this line:
bs_MAGEversion=instance_variable_get("#bs_MAGEversion") #doesn't seem to work
instance_variable_get isn't retrieving from the mi_h Object, which is where your value is stored. The way you've used it, that line is equivalent to:
bs_MAGEversion=#bs_MAGEversion
Changing it to mi_h.instance_variable_get would work. It would also be painfully ugly ruby. But I sense that's not quite what you're after. If I read you correctly, you want this line:
mi_h.load_settings()
to populate #bs_MAGEversion and #bs_mode in your Pre_start object. Ruby doesn't quite work that way. The closest thing to what you're looking for here would probably be a mixin, as described here:
http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_modules.html
We do something similar to this all the time in code at work. The problem, and solution, is proper use of variables and scoping in the main level of your code. We use YAML, you're using JSON, but the idea is the same.
Typically we define a constant, like CONFIG, which we load the YAML into, in our main code, and which is then available in all the code we require. For you, using JSON instead:
require 'json'
require_relative 'helper'
CONFIG = JSON.load_file('path/to/json')
At this point CONFIG would be available to the top-level code and in "helper.rb" code.
As an alternate way of doing it, just load your JSON in either file. The load-time is negligible and it'll still be the same data.
Since the JSON data should be static for the run-time of the program, it's OK to use it in a CONSTANT. Storing it in an instance variable only makes sense if the data would vary from instance to instance of the code, which makes no sense when you're loading data from a JSON or YAML-type file.
Also, notice that I'm using a method from the JSON class. Don't go through the rigamarole you're using to try to copy the JSON into the instance variable.
Stripping your code down as an example:
require 'fileutils'
require 'json'
CONTENTS = JSON.load_file('scripts/installer_settings.json')
class MAGEINSTALLER_Helper
def download(from,to)
puts "completed download for #{from}\n"
end
end
class Pre_start
def initialize(params=nil)
file = "www/depo/newfile-#{ CONFIG['bs_MAGEversion'] }.tar.gz"
if !File.exist?(file)
mi_h.download("http://www.dom.com/#{ CONFIG['bs_MAGEversion'] }/file-#{ CONFIG['bs_MAGEversion'] }.tar.gz", file)
else
puts "mage package exists"
end
end
end
CONFIG can be initialized/loaded in either file, just do it from the top-level before you need to access the contents.
Remember, Ruby starts executing it at the top of the first file and reads downward. Code that is outside of def, class and module blocks gets executed as it's encountered, so the CONFIG initialization will happen as soon as Ruby sees that code. If that happens before you start calling your methods and creating instances of classes then your code will be happy.

Accessing/Dealing with Variables in Ruby

Let me preface by stating I'm a "new" programmer - an IT guy trying his hand at his first "real" problem after working through various tutorials.
So - here is what I'm trying to do. I'm watching a directory for a .csv file - it will be in this format: 999999_888_filename.csv
I want to return each part of the "_" filename as a variable to pass on to another program/script for some other task. I have come up w/ the following code:
require 'rubygems'
require 'fssm'
class Watcher
def start
monitor = FSSM::Monitor.new(:directories => true)
monitor.path('/data/testing/uploads') do |path|
path.update do |base, relative, ftype|
output(relative)
end
path.create do |base, relative, ftype|
output(relative)
end
path.delete { |base, relative, ftype| puts "DELETED #{relative} (#{ftype})" }
end
monitor.run
end
def output(relative)
puts "#{relative} added"
values = relative.split('_',)
sitenum = values[0]
numrecs = values[1]
filename = values[2]
puts sitenum
end
end
My first "puts" gives me the full filename (it's just there to show me the script is working), and the second puts returns the 'sitenum'. I want to be able to access this "outside" of this output method. I have this file (named watcher.rb) in a libs/ folder and I have a second file in the project root called 'monitor.rb' which contains simply:
require './lib/watcher'
watcher = Watcher.new
watcher.start
And I can't figure out how to access my 'sitenum', 'numrecs' and 'filename' from this file. I'm not sure if it needs to be a variable, instance variable or what. I've played around w/ attr_accessible and other things, and nothing works. I decided to ask here since I've been spinning my wheels for a couple of things, and I'm starting to confuse myself by searching on my own.
Thanks in advance for any help or advice you may have.
At the top of the Watcher class, you're going to want to define three attr_accessor declarations, which give the behavior you want. (attr_reader if you're only reading, attr_writer if you're only writing, attr_accessor if both.)
class Watcher
attr_accessor :sitenum, :numrecs, :filename
...
# later on, use # for class variables
...
#sitenum = 5
...
end
Now you should have no problem with watcher.sitenum etc. Here's an example.
EDIT: Some typos.
In addition to Jordan Scales' answer, these variable should initialized
class Watcher
attr_accessor :sitenum, :numrecs, :filename
def initialize
#sitenum = 'default value'
#numrecs = 'default value'
#filename = 'default value'
end
...
end
Otherwise you'll get uninformative value nil

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