Merge pull request #6 from erayerdin/feat/overriding-manager-methods

Overriding Manager and QuerySet Methods

docs/usage.md

@@ -80,6 +80,8 @@ class FooView(TemplateView):
     This was only an example. You can already use custom template tags to get
     `Variable`s in templates, discussed in the next section.
 
+[^1]: See [installation](/#installation) section.
+
 ### Retrieving in Template
 
 In order to get a variable in a template, you need to first load
@@ -95,4 +97,20 @@ You can use `get_var` tag to get a `Variable`'s value:
 {% get_var "FOO" %}
 ```
 
-[^1]: See [installation](/#installation) section.
+## Updating A Variable
+
+You can update a single variable:
+
+```python
+variable.value = 5
+variable.save()
+# or
+variable.save(update_fields=("value",))
+```
+
+Or you can mass update on a `QuerySet`:
+
+```python
+variables = Variable.objects.filter(name__startswith="FOO")
+variables.update(value=5)
+```

persistent_settings/models.py

@@ -6,6 +6,31 @@ from django.db import models
 _LOGGER = logging.getLogger(__name__)
 
 
+def _change_value_kwarg(kwargs):
+    """
+    Changes `value` to `value_binary` by serializing it.
+    """
+
+    _LOGGER.debug("Removing `value_binary`...")
+    kwargs.pop("value_binary", None)
+
+    _LOGGER.debug("Serializing `value` to `value_binary`...")
+    value = kwargs.pop("value", None)
+    value_binary = pickle.dumps(value)
+    kwargs["value_binary"] = value_binary
+    return kwargs
+
+
+class _VariableQuerySet(models.QuerySet):
+    """
+    A special queryset for `Variable` model overriding default Django queryset.
+    """
+
+    def update(self, **kwargs):
+        _change_value_kwarg(kwargs)
+        return super().update(**kwargs)
+
+
 class _VariableManager(models.Manager):
     """
     A special manager for `Variable` model overriding default Django manager.
@@ -17,23 +42,13 @@ class _VariableManager(models.Manager):
         """
         return self.get(name=key).value
 
-    def create(self, **kwargs):
-        """
-        Creates a `Variable` instance.
+    def get_queryset(self):
+        _LOGGER.debug("Initializing `_VariableQuerySet`...")
+        return _VariableQuerySet(self.model, using=self._db)
 
-        Serializes `value` to `value_binary` field using `pickle`.
-
-        If no `value` is given, `None` is serialized.
-        """
-
-        _LOGGER.debug("Deleting `value_binary` kwarg...")
-        kwargs.pop("value_binary", None)
-
-        _LOGGER.debug("Serializing `value`...")
-        value = kwargs.pop("value", None)
-        value_binary = pickle.dumps(value)
-
-        return super().create(value_binary=value_binary, **kwargs)
+    def create(self, **kwargs):
+        _change_value_kwarg(kwargs)
+        return super().create(**kwargs)
 
 
 class Variable(models.Model):

project/settings.py

@@ -115,5 +115,18 @@ STATIC_URL = "/static/"
 
 #################
 
+LOGGING = {
+    "version": 1,
+    "disable_existing_loggers": False,
+    "handlers": {"stream": {"level": "DEBUG", "class": "logging.StreamHandler",},},
+    "loggers": {
+        "persistent_settings": {
+            "handlers": ["stream"],
+            "level": "DEBUG",
+            "propagate": True,
+        },
+    },
+}
+
 INSTALLED_APPS.append("persistent_settings")
 MIDDLEWARE.append("persistent_settings.middlewares.PersistentSettingsMiddleware")

project/tests/test_managers.py

+import pytest
+
+from persistent_settings import models
+
+
+@pytest.mark.describe("Overriding `_VariableManager`'s Default Methods")
+class TestOverrideVariableManager:
+    @pytest.mark.it("`create` method")
+    def test_create(self, db):
+        v = models.Variable.objects.create(name="FOO", value=5)
+        assert v.value == 5
+
+    @pytest.mark.it("`update` method")
+    def test_update(self, variable_factory):
+        for i in range(2):
+            variable_factory("bar", "FOO{}".format(i))
+
+        variables = models.Variable.objects.filter(name__startswith="FOO")
+        variables.update(value="baz")
+
+        for v in variables:
+            assert v.value == "baz"