FEATURE: Admin interface for adding custom fields for users

app/controllers/admin/user_fields_controller.rb

@@ -0,0 +1,30 @@
+class Admin::UserFieldsController < Admin::AdminController
+
+  def create
+    field = UserField.create!(params.require(:user_field).permit(:name, :field_type))
+    render_serialized(field, UserFieldSerializer)
+  end
+
+  def index
+    render_serialized(UserField.all, UserFieldSerializer, root: 'user_fields')
+  end
+
+  def update
+    field_params = params.require(:user_field)
+
+    field = UserField.where(id: params.require(:id)).first
+    field.name = field_params[:name]
+    field.field_type = field_params[:field_type]
+    field.save
+
+    render_serialized(field, UserFieldSerializer)
+  end
+
+  def destroy
+    field = UserField.where(id: params.require(:id)).first
+    field.destroy if field.present?
+    render nothing: true
+  end
+
+end
+