Problems using Maruku in Rails 3

Question

I am new to Rails but have used PHP extensively over the years. I am building a simple blog (I know) to get my skills up in the MVC/Rails world.

I have the basics working but have spent the weekend trying to get Maruku to work eg a post body saved from a text area with Markdown Extra markup to the db and then back again to the browser.

I used the following code in my Post model but I get an error when I try to load /posts - "undefined local variable or method `maruku' for #"

class Post < ActiveRecord::Base
validates :name,  :presence => true
validates :title, :presence => true,
                :length => { :minimum => 5 }
validates :content,  :presence => true
validates :excerpt,  :presence => true

has_many :comments, :dependent => :destroy

maruku.new(:content).to_html

end

I also tried something similar in my Posts Controller that I found on here. Then called @post.content in my Show view but get an error:

body = maruku.new(post.body)
post.body = body.to_html

I am dead sure it's my noob brain being dead but any help or direction would be great as I have fought with this for two days now. BTW I am using maruku as I need Markdown Extra as my old blog posts are all formatted that way.

Thanks

UPDATED - PostsController

class PostsController < ApplicationController

# GET /posts
# GET /posts.xml
def index
@posts = Post.find(:all, :order => 'created_at DESC')

respond_to do |format|
format.html # index.html.erb
format.xml  { render :xml => @posts }
end
end

# GET /posts/1
# GET /posts/1.xml
def show
@post = Post.find(params[:id])

respond_to do |format|
format.html # show.html.erb
format.xml  { render :xml => @post }
end
end

# GET /posts/new
# GET /posts/new.xml
def new
@post = Post.new

respond_to do |format|
format.html # new.html.erb
format.xml  { render :xml => @post }
end
end

# GET /posts/1/edit
def edit
@post = Post.find(params[:id])
end


# POST /posts
# POST /posts.xml
def create
@post = Post.new(params[:post])

respond_to do |format|
if @post.save
format.html { redirect_to(@post, :notice => 'Post was successfully created.') }
format.xml  { render :xml => @post, :status => :created, :location => @post }
else
format.html { render :action => "new" }
format.xml  { render :xml => @post.errors, :status => :unprocessable_entity }
end
end
end

# PUT /posts/1
# PUT /posts/1.xml
def update
@post = Post.find(params[:id])

respond_to do |format|
if @post.update_attributes(params[:post])
format.html { redirect_to(@post, :notice => 'Post was successfully updated.') }
format.xml  { head :ok }
else
format.html { render :action => "edit" }
format.xml  { render :xml => @post.errors, :status => :unprocessable_entity }
end
end
end

# DELETE /posts/1
# DELETE /posts/1.xml
def destroy
@post = Post.find(params[:id])
@post.destroy

respond_to do |format|
format.html { redirect_to(posts_url) }
format.xml  { head :ok }
end
end
end

Answer 1

You need to use (note the case):

Maruku.new(...)

Constants in ruby begin in an upper case letter and variables begin in a lower case letter (you are accessing a class, which is a constant).

Also, ensure that you include the gem in your Gemfile (Rails 3 requires all libraries be specified in this file).

Finally, you can not use Maruku as you listed. Instead, try:

class Post < ActiveRecord::Base

  ...

  def content_html
      Maruku.new(self.content).to_html    
  end

end

Then in your view, you can access through <%= @post.content_html %>. Note, you should probably do a conversion to HTML using a callback (see Active Record Callbacks) for improved performance at some point, but this should get you up and running.