Render the changelog in the admin interface

Make it easier for admins to read about new features that have been
added to Alaveteli from within Alaveteli itself.

Gemfile

@@ -114,6 +114,7 @@ gem 'recaptcha', '~> 5.15.0', require: 'recaptcha/rails'
 gem 'matrix', '~> 0.4.2'
 gem 'mini_magick', '~> 4.12.0'
 gem 'net-protocol', '~> 0.1.3'
+gem 'redcarpet', '~> 3.6.0'
 gem 'redis', '~> 4.8.1'
 gem 'rolify', '~> 6.0.1'
 gem 'ruby-msg', '~> 1.5.0', git: 'https://github.com/mysociety/ruby-msg.git', branch: 'ascii-encoding'

Gemfile.lock

@@ -420,6 +420,7 @@ GEM
     rainbow (3.1.1)
     rake (13.0.6)
     recaptcha (5.15.0)
+    redcarpet (3.6.0)
     redis (4.8.1)
     redlock (1.3.2)
       redis (>= 3.0.0, < 6.0)
@@ -627,6 +628,7 @@ DEPENDENCIES
   rails-controller-testing
   rails-i18n (~> 7.0.5)
   recaptcha (~> 5.15.0)
+  redcarpet (~> 3.6.0)
   redis (~> 4.8.1)
   rolify (~> 6.0.1)
   routing-filter (~> 0.7.0)

app/controllers/admin/changelog_controller.rb

@@ -0,0 +1,9 @@
+# Controller to render the changelog notes in a more human-friendly way within
+# the admin interface.
+class Admin::ChangelogController < AdminController
+  def index
+    markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML.new)
+    text = File.read(Rails.root + 'doc/CHANGES.md')
+    @changelog = markdown.render(text).html_safe
+  end
+end

app/views/admin/changelog/index.html.erb

@@ -0,0 +1,17 @@
+<% @title = 'Alaveteli Changelog' %>
+
+<h1><%= @title %></h1>
+
+<p>
+  The changelog documents the features and upgrade notes for each versioned
+  release of Alaveteli. Here you will see the changelog for the version of
+  Alaveteli you have installed. You can check GitHub for
+  <a href="https://github.com/mysociety/alaveteli/releases">newer releases of
+  Alaveteli</a> and preview upcoming changes in the
+  <a href="https://github.com/mysociety/alaveteli/blob/develop/doc/CHANGES.md">
+  development version of the changelog</a>.
+</p>
+
+<hr />
+
+<%= @changelog %>

app/views/layouts/admin.html.erb

@@ -44,13 +44,16 @@
     <div class="admin-footer">
       <div class="container">
         <div class="row">
-          <span class="span4 offset8">
+          <span class="span5 offset7">
             <ul class="nav nav-pills">
               <li>
                 <a href="http://alaveteli.org/docs/running/admin_manual/">
                   Admin Manual
                 </a>
               </li>
+              <li>
+                <%= link_to 'Changelog', admin_changelog_index_path %>
+              </li>
               <li>
                 <a href="http://alaveteli.org/community/">
                   Alaveteli Community

config/routes.rb

@@ -516,6 +516,12 @@ def matches?(request)
   end
   ####
 
+  #### Admin::Changelog controller
+  namespace :admin do
+    resources :changelog, only: [:index]
+  end
+
+  ####
   #### AdminTag controller
   namespace :admin do
     resources :tags, param: :tag, only: [:index, :show]

spec/controllers/admin/changelog_controller_spec.rb

@@ -0,0 +1,15 @@
+require 'spec_helper'
+
+RSpec.describe Admin::ChangelogController do
+  describe 'GET index' do
+    render_views
+
+    before do
+      get :index
+    end
+
+    it 'renders the changelog as HTML' do
+      expect(response.body).to match('<h2>Highlighted Features</h2>')
+    end
+  end
+end