ActiveVersioning Workflow

ActiveVersioning Workflow is an extension of ActiveVersioning that provides version workflow for ActiveAdmin-based CMSes.

ActiveVersioning Workflow is designed for ActiveAdmin, ActiveMaterial, and Rails 4.2+ applications, so ensure you have the following in your gemfile:

gem 'activeadmin', github: 'activeadmin'
gem 'devise' # Necessary if using standard ActiveAdmin configuration
gem 'active_material', git: 'git@github.com:vigetlabs/active_material.git'

These should all be installed and configured as well.

Add this line to your application's Gemfile:

gem 'active_versioning_workflow', git: 'git@github.com:vigetlabs/active_versioning_workflow.git'

And then execute:

$ bundle install
$ rails generate active_versioning:workflow
$ bundle exec rake db:migrate

After installing all the necessary gems, there are a handful of things to do in order to get versioning workflow in place for an ActiveAdmin resource:

1. Configure models for versioning
2. Pull in necessary styles and javascript
3. Add versioned routes to the routes file
4. Include the workflow controller module to the ActiveAdmin resource
5. Configure how versioned resources are displayed in ActiveAdmin
6. Set up live preview (optional)

First off, if you haven't already configured the models you'd like to have versioned, follow the steps in the ActiveVersioning README.

We'll need to pull in some CSS and JS for versioning to look and function correctly in ActiveAdmin.

In app/assets/javascripts/active_admin.js.coffee, add:

#= require active_versioning/workflow

In app/assets/stylesheets/active_admin.scss, add the following after the other ActiveAdmin-related import statements:

@import "active_versioning/workflow";

The generator for ActiveVersioning Workflow includes a router module that provides a versioned_routes method inside the main Rails routes block. It takes a list of underscored model names and generates version routes for each of the given models:

Rails.application.routes.draw do
  self.class.send(:include, ActiveVersioning::Workflow::Router) # Inserted after running the generator
  devise_for :admin_users, ActiveAdmin::Devise.config           # Inserted by an ActiveAdmin install
  ActiveAdmin.routes(self)                                      # Inserted by an ActiveAdmin install

  namespace :admin do
    versioned_routes :posts

    # If the Post model was namespaced -- something like Blog::Post -- you'd need to do the following based on how AA sets up routes:
    versioned_routes :blog_posts
  end
end

In a fresh ActiveAdmin-based Rails app, this is what your routes file would look like in order to manage a versioned Post model in ActiveAdmin under the :admin namespace (default namespace for ActiveAdmin). If you have ActiveAdmin configured differently and are using different namespaces, you'll want to use versioned_routes in the appropriate context.

In this example, we'd get routes like /admin/posts/1/versions and /admin/posts/1/versions/1.

Note: If you are using a different attribute for admin URLs (eg: slug or friendly_id), then you'll need to manually specify this in app/admin/version.rb after running the generator. Running with the Post example, that would look like so:

ActiveAdmin.register Version do
  # ...

  controller do
    # Override the finder option if all your versioned models use the same thing, like `finder: :find_by_slug!` for example.
    ActiveVersioning.versioned_models.each do |model|
      belongs_to model.name.underscore.gsub('/', '_').to_sym, class_name: model.name, polymorphic: true, finder: :find_by_id!
    end

    # Otherwise, either replace the above block or explicitly add a `belongs_to` statement for each non-standard model:
    belongs_to :post, polymorphic: true, finder: :find_by_slug!

    # ...
  end
end

Running with the example of a versioned Post model, we should have a file that registers the Post model with ActiveAdmin (generated with the rails generate active_admin:resource Post command and probably lives at app/admin/post.rb). At the top of the register block, include the controller module:

ActiveAdmin.register Post do
  include ActiveVersioning::Workflow::Controller
end

This adds the necessary actions to the admin controller for our resource so we can work with versions.

Use the draft_actions method over the default actions method at the end of the form block:

ActiveAdmin.register Post do
  include ActiveVersioning::Workflow::Controller

  form do |f|
    inputs do
      input :title
      input :body
    end

    draft_actions
  end
end

This pulls a label from t('active_versioning.actions.draft'), which is included in the generated locale file for ActiveVersioning Workflow. It defaults to "Save Draft".

Finally, we'll want to configure the show page for our versioned resource. This is done in a similar style to the regular show block in ActiveAdmin, except that we'll use show_version and version_attributes_panel:

ActiveAdmin.register Post do
  include ActiveVersioning::Workflow::Controller

  permit_params :title, :body

  show_version do |version|
    version_attributes_panel(version) do
      attributes_table_for(version) do
        row :title
        row :body
      end
    end
  end
end

When all is said and done, this will give us an awesome interface for version workflow in ActiveAdmin:

ActiveVersioning Workflow allows for some optional basic previewing functionality that leverages the non-admin controller for a resource. If you'd like to take advantage of previewing, here's how you'll want to set it up:

class PostsController < ApplicationController
  extend ActiveVersioning::Workflow::Previewable

  preview_resource :post

  def show
  end

  private

  def post
    @post ||= Post.find(params[:id])
  end
  helper_method :post
end

The extend adds the necessary functionality and preview_resource class method to the controller. Previewing only works for show pages where there's a single resource to preview, so you'll need a show method (and the corresponding route in your routes file) and then point the preview_resource at the reader method for the versioned resource.

In the ActiveAdmin draft panel, you'll see an extra preview button:

This will open a new window with our PostsController#show rendered out with the current draft version of our post.

You'll also be able to use actions_with_preview in place of actions inside the default index block in an ActiveAdmin resource definition:

ActiveAdmin.register Post do
  include ActiveVersioning::Workflow::Controller

  permit_params :title, :body

  index do
    column :title

    actions_with_preview
  end
end

If you're using the above preview functionality, you can also tap into some optional -- somewhat experimental -- real-time live preview on edit pages.

To use the real-time live preview, there's some additional setup required.

Mount ActiveVersioning Workflow's routes:

# config/routes.rb

mount ActiveVerioning::Workflow::Engine, as: 'active_versioning'

Inside a JS file included into the asset pipeline, invoke the previewer with:

//= require active_versioning/live-preview

var updater = ActivePreview({
  // URL to the page to preview
  url: "http://example.com/preview",

  // Where to find live-preview.html
  frameSrc: "/active-versioning/live-preview.html"
});

// Use updater however you want to emit an update. For example, with Colonel Kurtz
var editor = new ColonelKurtz();

editor.listen(updater);