Emmett

Welcome to the first part of the tutorial. We will start a new hobo project, set up a model to hold blog entries, and add markdown formatting.

To create our new hobo project, we use this command:

$ hobo blog

You will see a load of output. This is the scripts of hobo and rails setting up everything we need to get started. We will now create a model to hold our posts with this command:

$ cd blog
$ script/generate hobo_model_resource entry name:string body_markdown:text body_html:html

You’ll be presented with more output. Hobo’s scripts have created several things for us. The most important at the moment is a new model, entry, which has three fields: A string field called name, a text field called body_markdown, and a html field called body_html. What’s the difference between text and html fields? Text fields are escaped when viewed. They are the same otherwise. Let’s make it so our posts are can be written in markdown. This is our first bit of coding! Open a new file in the project directory called app/models/markdown_wrapper.rb and insert the following ruby:

require 'rubygems'
require 'maruku'

class MarkdownWrapper
  def before_save(record)
    record.body_html = Maruku.new(record.body_markdown).to_html
  end
end

What this little piece of code does is every time our model is about to be saved, the text in body_text will be compiled into HTML by maruku and placed in body_html. There is one more thing to do to start to use it. Open app/models/entry.rb and add a line of before_save MarkdownWrapper.new after the line that reads hobo_model. Your code should look something like this:

class Entry < ActiveRecord::Base

  hobo_model # Don't put anything above this

  before_save MarkdownWrapper.new

  fields do
    name          :string
    body_markdown :text
    body_html     :html
    timestamps
  end


  # --- Permissions --- #

  def create_permitted?
    acting_user.administrator?
  end

  def update_permitted?
    acting_user.administrator?
  end

  def destroy_permitted?
    acting_user.administrator?
  end

  def view_permitted?(field)
    true
  end

end

See our fields in the fields do block? The timestamps are created_at and updated_at datetime fields, which are added by hobo. Now all we have to do is apply the changes to the database. We do that with this command:

$ script/generate hobo_migration

Hobo will generate the database migration for us. You will see that it is creating a users table in addition to our entries table. Enter m to save the migration and apply it to our database. It will ask you to name the migration. This can be whatever you want. I like to use initial on the first one. Let’s fire up the development server and take a look!

$ script/server

Navigate to http://localhost:3000/ and you’ll see the new hobo app! It will have you create a new administrator user. Then, you can create your blog posts! A lot of functionality has been accomplished with a few lines, but the interface is awkward. We will fix this in the next portion of the tutorial.