Implement AdapterMethodField; close #13

Author: alexei

adapters/fields.py

@@ -10,6 +10,7 @@
 
 
 __all__ = [
+    'AdapterMethodField',
     'BooleanField',
     'CharField',
     'DateField',
@@ -22,6 +23,19 @@
 ]
 
 
+class AdapterMethodField(BaseField):
+    def __init__(self, method_name=None):
+        self.method_name = method_name
+
+    def bind(self, field_name, adapter):
+        self.field_name = field_name
+        self.adapter = adapter
+
+    def get_attribute(self, obj):
+        metod_name = self.method_name or 'get_' + self.field_name
+        return getattr(self.adapter, metod_name)(obj)
+
+
 class BooleanField(BaseField):
     def adapt(self, data):
         return bool(data)

tests/fixtures.py

@@ -58,3 +58,22 @@ class PersonDictAdapter(adapters.Adapter):
 class ListToDictAdapter(adapters.Adapter):
     first_name = adapters.VerbatimField(source='0')
     last_name = adapters.VerbatimField(source='2')
+
+
+class MethodicalAdapter(adapters.Adapter):
+    min = adapters.AdapterMethodField()
+    max = adapters.AdapterMethodField()
+    sum = adapters.AdapterMethodField(method_name='compute_sum')
+    avg = adapters.AdapterMethodField(method_name='compute_avg')
+
+    def get_min(self, data):
+        return min(data)
+
+    def get_max(self, data):
+        return max(data)
+
+    def compute_sum(self, data):
+        return sum(data)
+
+    def compute_avg(self, data):
+        return sum(data) / len(data)

tests/test_adapter.py

@@ -1,7 +1,6 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import unicode_literals
-from __future__ import absolute_import
 
 import unittest
 

tests/test_fields.py

@@ -6,10 +6,11 @@
 from decimal import Decimal
 import unittest
 
-import adapters
-
 import dateutil.tz
 
+import adapters
+import fixtures
+
 
 class FieldsTest(unittest.TestCase):
     def test_char_field(self):
@@ -129,3 +130,14 @@ def test_datetime_field_from_string(self):
         actual = adapters.DateTimeField().adapt(data)
         expected = datetime.datetime(1986, 7, 25, 13, 14)
         self.assertEqual(actual, expected)
+
+    def test_adapter_method_field(self):
+        data = [1, 2, 3, 4, 5]
+        actual = fixtures.MethodicalAdapter().adapt(data)
+        expected = {
+            'min': 1,
+            'max': 5,
+            'sum': 15,
+            'avg': 3,
+        }
+        self.assertDictEqual(actual, expected)