Introduce permanent and customizable procedure url

app/validators/procedure_path_format_validator.rb

@@ -0,0 +1,16 @@
+class ProcedurePathFormatValidator < ActiveModel::Validator
+
+  def path_regex
+    /^[a-z0-9_]{3,30}$/
+  end
+
+  def validate(record)
+    return false if record.path.blank?
+    record.errors[:path] << "Path invalide" unless path_regex.match(record.path)
+  end
+
+  def validate_string(path)
+    return false if path.blank?
+    path_regex.match(path)
+  end
+end