1 files changed, 19 insertions, 0 deletions
diff --git a/users/app/models/login_format_validation.rb b/users/app/models/login_format_validation.rb
new file mode 100644
index 0000000..1d02bd1
--- /dev/null
+++ b/users/app/models/login_format_validation.rb
@@ -0,0 +1,19 @@
+module LoginFormatValidation
+  extend ActiveSupport::Concern
+
+  included do
+    # Have multiple regular expression validations so we can get specific error messages:
+    validates :login,
+      :format => { :with => /\A.{2,}\z/,
+        :message => "Login must have at least two characters"}
+    validates :login,
+      :format => { :with => /\A[a-z\d_\.-]+\z/,
+        :message => "Only lowercase letters, digits, . - and _ allowed."}
+    validates :login,
+      :format => { :with => /\A[a-z].*\z/,
+        :message => "Login must begin with a lowercase letter"}
+    validates :login,
+      :format => { :with => /\A.*[a-z\d]\z/,
+        :message => "Login must end with a letter or digit"}
+  end
+end