Add some custom FormEncode validators.

tailbone/forms/validators.py

@@ -0,0 +1,76 @@
+# -*- coding: utf-8 -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2015 Lance Edgar
+#
+#  This file is part of Rattail.
+#
+#  Rattail is free software: you can redistribute it and/or modify it under the
+#  terms of the GNU Affero General Public License as published by the Free
+#  Software Foundation, either version 3 of the License, or (at your option)
+#  any later version.
+#
+#  Rattail is distributed in the hope that it will be useful, but WITHOUT ANY
+#  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#  FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#  more details.
+#
+#  You should have received a copy of the GNU Affero General Public License
+#  along with Rattail.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+"""
+Custom FormEncode Validators
+"""
+
+from __future__ import unicode_literals
+
+from rattail.db import model
+
+import formencode
+from formencode import validators
+
+from tailbone.db import Session
+
+
+class ValidCustomer(validators.FancyValidator):
+    """
+    Validator for customer field.
+    """
+
+    def _to_python(self, value, state):
+        if not value:
+            return None
+        customer = Session.query(model.Customer).get(value)
+        if not customer:
+            raise formencode.Invalid("Customer not found", value, state)
+        return customer
+
+
+class ValidProduct(validators.FancyValidator):
+    """
+    Validator for product field.
+    """
+
+    def _to_python(self, value, state):
+        if not value:
+            return None
+        product = Session.query(model.Product).get(value)
+        if not product:
+            raise formencode.Invalid("Product not found", value, state)
+        return product
+
+
+class ValidUser(validators.FancyValidator):
+    """
+    Validator for product field.
+    """
+
+    def to_python(self, value, state):
+        if not value:
+            return None
+        user = Session.query(model.User).get(value)
+        if not user:
+            raise formencode.Invalid("User not found.", value, state)
+        return user