refs #107 Add a mechanism to validate data in UrlProxy

agnocomplete/core.py

@@ -17,7 +17,9 @@
 from .constants import AGNOCOMPLETE_MAX_PAGESIZE
 from .constants import AGNOCOMPLETE_DEFAULT_QUERYSIZE
 from .constants import AGNOCOMPLETE_MIN_QUERYSIZE
-from .exceptions import AuthenticationRequiredAgnocompleteException, SkipItem
+from .exceptions import AuthenticationRequiredAgnocompleteException
+from .exceptions import SkipItem
+from .exceptions import ItemNotFound
 
 
 logger = logging.getLogger(__name__)
@@ -641,3 +643,25 @@ def selected(self, ids):
                             )
                         )
         return data
+
+    def validate(self, value):
+        """
+        From a value available on the remote server, the method returns the
+        complete item matching the value.
+        If case the value is not available on the server side or filtered
+        through :meth:`item`, the class:`agnocomplete.exceptions.ItemNotFound`
+        is raised.
+        """
+
+        url = self.get_item_url(value)
+        try:
+            data = self.http_call(url=url)
+        except requests.HTTPError:
+            raise ItemNotFound()
+
+        data = self.get_http_result(data)
+
+        try:
+            return self.item(data)
+        except SkipItem:
+            raise ItemNotFound()

agnocomplete/exceptions.py

@@ -37,3 +37,7 @@ class SkipItem(Exception):
     Occurs when Item has to be skipped when building the final Payload
     """
     pass
+
+
+class ItemNotFound(Exception):
+    pass

agnocomplete/fields.py

@@ -3,13 +3,15 @@
 
 """
 from django import forms
+from django.core.exceptions import ValidationError
 
 import six
 
 from .core import AgnocompleteBase
 from .constants import AGNOCOMPLETE_USER_ATTRIBUTE
 from .widgets import AgnocompleteSelect, AgnocompleteMultiSelect
 from .register import get_agnocomplete_registry
+from .exceptions import ItemNotFound
 from .exceptions import UnregisteredAgnocompleteException
 
 
@@ -246,3 +248,21 @@ def clean(self, value):
         qs = super(AgnocompleteModelMultipleField, self).clean(pks)
 
         return qs
+
+
+class AgnocompleteUrlProxyMixin(object):
+    """
+    This mixin can be used with a field which actually using
+    :class:`agnocomplete.core.AutocompletUrlProxy`. The main purpose is to
+    provide a mechanism to validate the value through the Autocomplete.
+    """
+
+    def clean(self, value):
+        try:
+            return self.agnocomplete.validate(value)
+        except ItemNotFound:
+            raise ValidationError(
+                self.error_messages['invalid_choice'],
+                code='invalid_choice',
+                params={'value': value}
+            )