refractor code into different files

app/helpers/users_helper.rb

@@ -0,0 +1,58 @@
+module UsersHelper
+  ##
+  # Includes functions related to users
+  ##
+  # Set devise_mapping for devise so that we can call the devise help links (views/devise/shared/_links) from anywhere (eg sign_up form in proposals#new)
+  def devise_mapping
+    @devise_mapping ||= Devise.mappings[:user]
+  end
+
+  def omniauth_configured
+    providers = []
+    Devise.omniauth_providers.each do |provider|
+      provider_key = "#{provider}_key"
+      provider_secret = "#{provider}_secret"
+      unless Rails.application.secrets.send(provider_key).blank? || Rails.application.secrets.send(provider_secret).blank?
+        providers << provider
+      end
+      providers << provider if !ENV["OSEM_#{provider.upcase}_KEY"].blank? && !ENV["OSEM_#{provider.upcase}_SECRET"].blank?
+    end
+
+    return providers.uniq
+  end
+
+  # Receives a hash, generated from User model, function get_roles
+  # Outputs the roles of a user, including the conferences for which the user has the roles
+  # Eg. organizer(oSC13, oSC14), cfp(oSC12, oSC13)
+  def show_roles(roles)
+    roles.map{ |x| x[0].titleize + ' (' + x[1].join(', ') + ')' }.join ', '
+  end
+
+  def can_manage_volunteers(conference)
+    if (current_user.has_role? :organizer, conference) || (current_user.has_role? :volunteers_coordinator, conference)
+      true
+    else
+      false
+    end
+  end
+
+  def user_change_description(version)
+    if version.event == 'create'
+      link_to_user(version.item_id) + ' signed up'
+    elsif version.event == 'update'
+      if version.changeset.keys.include?('reset_password_sent_at')
+        'Someone requested password reset of'
+      elsif version.changeset.keys.include?('confirmed_at') && version.changeset['confirmed_at'][0].nil?
+        (version.whodunnit.nil? ? link_to_user(version.item_id) : link_to_user(version.whodunnit)) + ' confirmed account of'
+      elsif version.changeset.keys.include?('confirmed_at') && version.changeset['confirmed_at'][1].nil?
+        link_to_user(version.whodunnit) + ' unconfirmed account of'
+      else
+        link_to_user(version.whodunnit) + " updated #{updated_attributes(version)} of"
+      end
+    end
+  end
+
+  def users_role_change_description(version)
+    version.event == 'create' ? 'added' : 'removed'
+  end
+end