Roles into their own controller. Rework interface. Add flash messages to ajax calls. Add description to roles. Possible to edit roles in use.

app/controllers/admin/roles_controller.rb

@@ -0,0 +1,87 @@
+module Admin
+  class RolesController < Admin::BaseController
+    load_and_authorize_resource :conference, find_by: :short_title
+    before_action :set_selection
+    # Show flash message with ajax calls
+    after_action :prepare_unobtrusive_flash, only: :toggle_user
+
+    def index
+      @roles = Role.where(resource: @conference)
+    end
+
+    def show
+      @users = @role.users
+    end
+
+    def edit
+      @users = @role.users
+    end
+
+    def update
+      role_name = @role.name
+
+      if @role.update_attributes(role_params)
+        flash[:notice] = 'Successfully updated role ' + @role.name
+        redirect_to admin_conference_role_path(@conference.short_title, @role.name)
+      else
+        @role.name = role_name
+        flash[:error] = 'Could not update role! ' + @role.errors.full_messages.to_sentence
+        render :edit
+      end
+    end
+
+    def toggle_user
+      user = User.find_by(email: user_params[:email])
+      state = user_params[:state]
+
+      unless user
+        flash[:error] = 'Could not find user. Please provide a valid email!'
+        redirect_to(admin_conference_role_path(@conference.short_title, @role.name)) && return
+      end
+
+      # The conference must have at least 1 organizer
+      if @role.name == 'organizer' && state == 'false' && @role.users.count == 1
+        flash[:error] = 'The conference must have at least 1 organizer!'
+        redirect_to(admin_conference_role_path(@conference.short_title, @role.name)) && return
+      end
+
+      # Remove user
+      if state == 'false'
+        if user.remove_role @role.name, @conference
+          flash[:notice] = "Successfully removed role #{@role.name} from user #{user.email}"
+        else
+          flash[:error] = "Could not remove role #{@role.name} from user #{user.email}"
+        end
+      elsif user.has_role? @role.name, @conference
+        flash[:error] = "User #{user.email} already has the role #{@role.name}"
+        # Add user
+      elsif user.add_role @role.name, @conference
+        flash[:notice] = "Successfully added role #{@role.name} to user #{user.email}"
+      else
+        flash[:error] = "Coud not add role #{@role.name} to #{user.email}"
+      end
+
+      respond_to do |format|
+        format.js
+        format.html { redirect_to admin_conference_role_path(@conference.short_title, @role.name) }
+      end
+    end
+
+    protected
+
+    def set_selection
+      # Set 'organizer' as default role, when there is no other selection
+      @selection = params[:id] ? params[:id].parameterize.underscore : 'organizer'
+
+      @role = Role.find_by(name: @selection, resource: @conference)
+    end
+
+    def role_params
+      params.require(:role).permit(:name, :description, user_ids: [])
+    end
+
+    def user_params
+      params.require(:user).permit(:email, :state)
+    end
+  end
+end