adds an age property to the demographcis model

.envrc

@@ -0,0 +1,2 @@
+layout python python3.4
+

changelog.md

@@ -1,3 +1,8 @@
+### 0.14.0 (Major Release)
+
+Adds a `age` property to demographics that returns the patient's age.
+
+
 ### 0.13.0 (Major Release)
 
 #### Removes support for Python 2.x

opal/models.py

@@ -9,6 +9,7 @@
 import logging
 import random
 import os
+from dateutil.relativedelta import relativedelta
 
 from django.utils import timezone
 from django.db import models, transaction
@@ -1413,6 +1414,15 @@ class Demographics(PatientSubrecord):
     def name(self):
         return '{0} {1}'.format(self.first_name, self.surname)
 
+    @property
+    def age(self):
+        if self.date_of_birth:
+            today = datetime.date.today()
+            return relativedelta(
+                today,
+                self.date_of_birth
+            ).years
+
     class Meta:
         abstract = True
         verbose_name_plural = "Demographics"

opal/tests/test_models.py

@@ -819,6 +819,16 @@ def test_name(self):
                                 middle_name='Obsidian')
         self.assertEqual('Jane Doe', d.name)
 
+    def test_age_no_date_of_birth(self):
+        d = models.Demographics(date_of_birth=None)
+        self.assertIsNone(d.age)
+
+    @patch("opal.models.datetime")
+    def test_age(self, dt):
+        dt.date.today.return_value = datetime.date(2017, 3, 1)
+        d = models.Demographics(date_of_birth=datetime.date(2016, 1, 28))
+        self.assertEqual(d.age, 1)
+
 
 class ExternalSystemTestCase(OpalTestCase):
     def test_get_footer(self):