Add the ability for field types to update themselves

2 files changed, 148 insertions, 2 deletions

diff --git a/lesana/types.py b/lesana/types.py
index 500f21e..7f182ea 100644
--- a/lesana/types.py
+++ b/lesana/types.py
@@ -27,6 +27,16 @@ class LesanaType:
     def empty(self):
         raise NotImplementedError
 
+    def update(self, value):
+        """
+        Return an updated value, as appropriate for the field.
+
+        Default is to return the value itself, but types can use their
+        configuration to e.g. increment a numerical value or return the
+        current date(time).
+        """
+        return value
+
     def _to_index_text(self, value):
         """
         Prepare a value for indexing.
@@ -212,11 +222,24 @@ class LesanaDatetime(LesanaType):
             )
 
     def empty(self):
-        if self.field.get('auto', False) == 'creation':
+        if self.field.get('auto', False) in ('creation', 'update'):
             return datetime.datetime.now(datetime.timezone.utc)
 
         return None
 
+    def update(self, value):
+        """
+        Return an updated value.
+
+        If the field settings ``auto`` is ``update`` return the current
+        datetime, otherwise the old value.
+
+        """
+        if self.field.get('auto', False) == 'update':
+            return datetime.datetime.now(datetime.timezone.utc)
+
+        return value
+
 
 class LesanaDate(LesanaType):
     """
@@ -239,11 +262,24 @@ class LesanaDate(LesanaType):
             )
 
     def empty(self):
-        if self.field.get('auto', False) == 'creation':
+        if self.field.get('auto', False) in ('creation', 'update'):
             return datetime.date.today()
 
         return None
 
+    def update(self, value):
+        """
+        Return an updated value.
+
+        If the field settings ``auto`` is ``update`` return the current
+        date, otherwise the old value.
+
+        """
+        if self.field.get('auto', False) == 'update':
+            return datetime.date.today()
+
+        return value
+
 
 class LesanaBoolean(LesanaType):
     """
diff --git a/tests/test_types.py b/tests/test_types.py
index 9663288..260167c 100644
--- a/tests/test_types.py
+++ b/tests/test_types.py
@@ -42,6 +42,9 @@ class testTypes(unittest.TestCase):
         s = checker.load(None)
         self.assertEqual(s, None)
 
+        v = checker.update("Hello World!")
+        self.assertEqual(v, "Hello World!")
+
     def test_text(self):
         checker = types.LesanaText(self._get_field_def('text'), {})
 
@@ -54,6 +57,9 @@ class testTypes(unittest.TestCase):
         s = checker.load(None)
         self.assertEqual(s, None)
 
+        v = checker.update("Hello World!")
+        self.assertEqual(v, "Hello World!")
+
     def test_int(self):
         checker = types.LesanaInt(self._get_field_def('integer'), {})
 
@@ -73,6 +79,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(10)
+        self.assertEqual(v, 10)
+
     def test_float(self):
         checker = types.LesanaFloat(self._get_field_def('float'), {})
 
@@ -95,6 +104,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(10.5)
+        self.assertEqual(v, 10.5)
+
     def test_decimal(self):
         checker = types.LesanaDecimal(self._get_field_def('decimal'), {})
 
@@ -117,6 +129,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(decimal.Decimal("10.5"))
+        self.assertEqual(v, decimal.Decimal("10.5"))
+
     def test_timestamp(self):
         checker = types.LesanaTimestamp(self._get_field_def('timestamp'), {})
 
@@ -147,6 +162,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(today)
+        self.assertEqual(v, today)
+
     def test_datetime(self):
         checker = types.LesanaDatetime(self._get_field_def('datetime'), {})
 
@@ -176,6 +194,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(now)
+        self.assertEqual(v, now)
+
     def test_datetime_auto(self):
         field_def = self._get_field_def('datetime')
         field_def['auto'] = 'creation'
@@ -193,6 +214,42 @@ class testTypes(unittest.TestCase):
         v = checker.empty()
         self.assertEqual(v, None)
 
+        # auto=update fields should also be filled at creation time
+        field_def['auto'] = 'update'
+        checker = types.LesanaDatetime(field_def, {})
+        v = checker.empty()
+        self.assertIsInstance(v, datetime.datetime)
+        self.assertEqual(v.tzinfo, datetime.timezone.utc)
+        self.assertEqual(v.year, now.year)
+
+    def test_datetime_auto_update(self):
+        field_def = self._get_field_def('datetime')
+        field_def['auto'] = 'update'
+        checker = types.LesanaDatetime(field_def, {})
+
+        now = datetime.datetime.now()
+        past = datetime.datetime(2016, 12, 10, 21, 2)
+        # we pass a date in the past
+        v = checker.update(past)
+        self.assertIsInstance(v, datetime.datetime)
+        self.assertEqual(v.tzinfo, datetime.timezone.utc)
+        # and we want to get a date in the present
+        self.assertEqual(v.year, now.year)
+
+        # with auto=False we want our old date instead
+        field_def['auto'] = False
+        checker = types.LesanaDatetime(field_def, {})
+
+        v = checker.update(past)
+        self.assertEqual(v, past)
+
+        # and the same should happen with auto=creation
+        field_def['auto'] = 'creation'
+        checker = types.LesanaDatetime(field_def, {})
+
+        v = checker.update(past)
+        self.assertEqual(v, past)
+
     def test_date(self):
         checker = types.LesanaDate(self._get_field_def('date'), {})
 
@@ -222,6 +279,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(today)
+        self.assertEqual(v, today)
+
     def test_date_auto(self):
         field_def = self._get_field_def('date')
         field_def['auto'] = 'creation'
@@ -238,6 +298,41 @@ class testTypes(unittest.TestCase):
         v = checker.empty()
         self.assertEqual(v, None)
 
+        # auto=update fields should also be filled at creation time
+        field_def['auto'] = 'update'
+        checker = types.LesanaDate(field_def, {})
+
+        v = checker.empty()
+        self.assertIsInstance(v, datetime.date)
+        self.assertEqual(v, today)
+
+    def test_date_auto_update(self):
+        field_def = self._get_field_def('date')
+        field_def['auto'] = 'update'
+        checker = types.LesanaDate(field_def, {})
+
+        today = datetime.date.today()
+        past = datetime.date(2016, 12, 10)
+        # we pass a date in the past
+        v = checker.update(past)
+        self.assertIsInstance(v, datetime.date)
+        # and we want to get a date in the present
+        self.assertEqual(v, today)
+
+        # with auto=False we want our old date instead
+        field_def['auto'] = False
+        checker = types.LesanaDate(field_def, {})
+
+        v = checker.update(past)
+        self.assertEqual(v, past)
+
+        # and the same should happen with auto=creation
+        field_def['auto'] = 'creation'
+        checker = types.LesanaDate(field_def, {})
+
+        v = checker.update(past)
+        self.assertEqual(v, past)
+
     def test_boolean(self):
         checker = types.LesanaBoolean(self._get_field_def('boolean'), {})
 
@@ -254,6 +349,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(True)
+        self.assertEqual(v, True)
+
     def test_file(self):
         checker = types.LesanaFile(self._get_field_def('file'), {})
 
@@ -268,6 +366,9 @@ class testTypes(unittest.TestCase):
 
         # TODO: check for invalid file paths
 
+        v = checker.update("relative/path/to/file")
+        self.assertEqual(v, "relative/path/to/file")
+
     def test_url(self):
         checker = types.LesanaURL(self._get_field_def('url'), {})
 
@@ -282,6 +383,9 @@ class testTypes(unittest.TestCase):
 
         # TODO: check for invalid URLs
 
+        v = checker.update("http://example.org")
+        self.assertEqual(v, "http://example.org")
+
     def test_yaml(self):
         checker = types.LesanaYAML(self._get_field_def('yaml'), {})
 
@@ -298,6 +402,9 @@ class testTypes(unittest.TestCase):
         v = checker.load(None)
         self.assertEqual(v, None)
 
+        v = checker.update(some_data)
+        self.assertEqual(v, some_data)
+
     def test_list(self):
         field_def = self._get_field_def('yaml')
         # we use one type that is easy to check for correct validation
@@ -318,6 +425,9 @@ class testTypes(unittest.TestCase):
             with self.assertRaises(types.LesanaValueError):
                 checker.load(d)
 
+        v = checker.update(some_data)
+        self.assertEqual(v, some_data)
+
     def test_list_unknown_subtype(self):
         field_def = self._get_field_def('yaml')
         # we use one type that is easy to check for correct validation