Add support for storing Float values (#80)

alexarnautu · web-flow · commit e4bd26ece29f · 2020-03-10T09:21:11.000+02:00
* Add LocalizedFloatValue

* Add LocalizedFloatField

* Add tests for float field

* Create LocalizedNumericValue with __int__ and __float__ methods
diff --git a/localized_fields/fields/__init__.py b/localized_fields/fields/__init__.py
@@ -5,6 +5,7 @@
 from .text_field import LocalizedTextField
 from .file_field import LocalizedFileField
 from .integer_field import LocalizedIntegerField
+from .float_field import LocalizedFloatField
 
 
 __all__ = [
@@ -14,7 +15,8 @@
     'LocalizedCharField',
     'LocalizedTextField',
     'LocalizedFileField',
-    'LocalizedIntegerField'
+    'LocalizedIntegerField',
+    'LocalizedFloatField'
 ]
 
 try:
diff --git a/localized_fields/fields/float_field.py b/localized_fields/fields/float_field.py
@@ -0,0 +1,91 @@
+from typing import Optional, Union, Dict
+
+from django.conf import settings
+from django.db.utils import IntegrityError
+
+from .field import LocalizedField
+from ..value import LocalizedValue, LocalizedFloatValue
+from ..forms import LocalizedIntegerFieldForm
+
+
+class LocalizedFloatField(LocalizedField):
+    """Stores float as a localized value."""
+
+    attr_class = LocalizedFloatValue
+
+    @classmethod
+    def from_db_value(cls, value, *_) -> Optional[LocalizedFloatValue]:
+        db_value = super().from_db_value(value)
+        if db_value is None:
+            return db_value
+
+        # if we were used in an expression somehow then it might be
+        # that we're returning an individual value or an array, so
+        # we should not convert that into an :see:LocalizedFloatValue
+        if not isinstance(db_value, LocalizedValue):
+            return db_value
+
+        return cls._convert_localized_value(db_value)
+
+    def to_python(self, value: Union[Dict[str, int], int, None]) -> LocalizedFloatValue:
+        """Converts the value from a database value into a Python value."""
+
+        db_value = super().to_python(value)
+        return self._convert_localized_value(db_value)
+
+    def get_prep_value(self, value: LocalizedFloatValue) -> dict:
+        """Gets the value in a format to store into the database."""
+
+        # apply default values
+        default_values = LocalizedFloatValue(self.default)
+        if isinstance(value, LocalizedFloatValue):
+            for lang_code, _ in settings.LANGUAGES:
+                local_value = value.get(lang_code)
+                if local_value is None:
+                    value.set(lang_code, default_values.get(lang_code, None))
+
+        prepped_value = super().get_prep_value(value)
+        if prepped_value is None:
+            return None
+
+        # make sure all values are proper floats
+        for lang_code, _ in settings.LANGUAGES:
+            local_value = prepped_value[lang_code]
+            try:
+                if local_value is not None:
+                    float(local_value)
+            except (TypeError, ValueError):
+                raise IntegrityError('non-float value in column "%s.%s" violates '
+                                     'float constraint' % (self.name, lang_code))
+
+            # convert to a string before saving because the underlying
+            # type is hstore, which only accept strings
+            prepped_value[lang_code] = str(local_value) if local_value is not None else None
+
+        return prepped_value
+
+    def formfield(self, **kwargs):
+        """Gets the form field associated with this field."""
+        defaults = {
+            'form_class': LocalizedIntegerFieldForm
+        }
+
+        defaults.update(kwargs)
+        return super().formfield(**defaults)
+
+    @staticmethod
+    def _convert_localized_value(value: LocalizedValue) -> LocalizedFloatValue:
+        """Converts from :see:LocalizedValue to :see:LocalizedFloatValue."""
+
+        float_values = {}
+        for lang_code, _ in settings.LANGUAGES:
+            local_value = value.get(lang_code, None)
+            if local_value is None or local_value.strip() == '':
+                local_value = None
+
+            try:
+                float_values[lang_code] = float(local_value)
+            except (ValueError, TypeError):
+                float_values[lang_code] = None
+
+        return LocalizedFloatValue(float_values)
diff --git a/localized_fields/value.py b/localized_fields/value.py
@@ -206,7 +206,31 @@ def localized(self):
         return self.get(translation.get_language())
 
 
-class LocalizedIntegerValue(LocalizedValue):
+class LocalizedNumericValue(LocalizedValue):
+    def __int__(self):
+        """Gets the value in the current language as an integer."""
+        value = self.translate()
+        if value is None:
+            return self.default_value
+
+        return int(value)
+
+    def __str__(self) -> str:
+        """Returns string representation of value"""
+
+        value = self.translate()
+        return str(value) if value is not None else ''
+
+    def __float__(self):
+        """Gets the value in the current language as a float"""
+        value = self.translate()
+        if value is None:
+            return self.default_value
+
+        return float(value)
+
+
+class LocalizedIntegerValue(LocalizedNumericValue):
     """All values are integers."""
 
     default_value = None
@@ -221,17 +245,19 @@ def translate(self):
 
         return int(value)
 
-    def __int__(self):
-        """Gets the value in the current language as an integer."""
 
-        value = self.translate()
-        if value is None:
-            return self.default_value
+class LocalizedFloatValue(LocalizedNumericValue):
+    """All values are floats"""
 
-        return int(value)
+    default_value = None
 
-    def __str__(self) -> str:
-        """Returns string representation of value"""
+    def translate(self):
+        """
+        Gets the value in the current language, or in the configured
+        fallback language.
+        """
+        value = super().translate()
+        if value is None or (isinstance(value, str) and value.strip() == ''):
+            return None
 
-        value = self.translate()
-        return str(value) if value is not None else ''
+        return float(value)
diff --git a/tests/test_float_field.py b/tests/test_float_field.py
@@ -0,0 +1,176 @@
+from django.test import TestCase
+from django.db.utils import IntegrityError
+from django.conf import settings
+from django.db import connection
+from django.utils import translation
+
+from localized_fields.fields import LocalizedFloatField
+
+from .fake_model import get_fake_model
+
+
+class LocalizedFloatFieldTestCase(TestCase):
+    """Tests whether the :see:LocalizedFloatField
+    and :see:LocalizedFloatValue works properly."""
+
+    TestModel = None
+
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+
+        cls.TestModel = get_fake_model({
+            'score': LocalizedFloatField()
+        })
+
+    def test_basic(self):
+        """Tests the basics of storing float values."""
+
+        obj = self.TestModel()
+        for index, (lang_code, _) in enumerate(settings.LANGUAGES):
+            obj.score.set(lang_code, index + 1.0)
+        obj.save()
+
+        obj = self.TestModel.objects.all().first()
+        for index, (lang_code, _) in enumerate(settings.LANGUAGES):
+            assert obj.score.get(lang_code) == index + 1.0
+
+    def test_primary_language_required(self):
+        """Tests whether the primary language is required by
+        default and all other languages are optiona."""
+
+        # not filling in anything should raise IntegrityError,
+        # the primary language is required
+        with self.assertRaises(IntegrityError):
+            obj = self.TestModel()
+            obj.save()
+
+        # when filling all other languages besides the primary language
+        # should still raise an error because the primary is always required
+        with self.assertRaises(IntegrityError):
+            obj = self.TestModel()
+            for lang_code, _ in settings.LANGUAGES:
+                if lang_code == settings.LANGUAGE_CODE:
+                    continue
+                obj.score.set(lang_code, 23.0)
+            obj.save()
+
+    def test_default_value_none(self):
+        """Tests whether the default value for optional languages
+        is NoneType."""
+
+        obj = self.TestModel()
+        obj.score.set(settings.LANGUAGE_CODE, 1234.0)
+        obj.save()
+
+        for lang_code, _ in settings.LANGUAGES:
+            if lang_code == settings.LANGUAGE_CODE:
+                continue
+
+            assert obj.score.get(lang_code) is None
+
+    def test_translate(self):
+        """Tests whether casting the value to an float
+        results in the value being returned in the currently
+        active language as an float."""
+
+        obj = self.TestModel()
+        for index, (lang_code, _) in enumerate(settings.LANGUAGES):
+            obj.score.set(lang_code, index + 1.0)
+        obj.save()
+
+        obj.refresh_from_db()
+        for index, (lang_code, _) in enumerate(settings.LANGUAGES):
+            with translation.override(lang_code):
+                assert float(obj.score) == index + 1.0
+                assert obj.score.translate() == index + 1.0
+
+    def test_translate_primary_fallback(self):
+        """Tests whether casting the value to an float
+        results in the value begin returned in the active
+        language and falls back to the primary language
+        if there is no value in that language."""
+
+        obj = self.TestModel()
+        obj.score.set(settings.LANGUAGE_CODE, 25.0)
+
+        secondary_language = settings.LANGUAGES[-1][0]
+        assert obj.score.get(secondary_language) is None
+
+        with translation.override(secondary_language):
+            assert obj.score.translate() == 25.0
+            assert float(obj.score) == 25.0
+
+    def test_get_default_value(self):
+        """Tests whether getting the value in a specific
+        language properly returns the specified default
+        in case it is not available."""
+
+        obj = self.TestModel()
+        obj.score.set(settings.LANGUAGE_CODE, 25.0)
+
+        secondary_language = settings.LANGUAGES[-1][0]
+        assert obj.score.get(secondary_language) is None
+        assert obj.score.get(secondary_language, 1337.0) == 1337.0
+
+    def test_completely_optional(self):
+        """Tests whether having all languages optional
+        works properly."""
+
+        model = get_fake_model({
+            'score': LocalizedFloatField(null=True, required=[], blank=True)
+        })
+
+        obj = model()
+        obj.save()
+
+        for lang_code, _ in settings.LANGUAGES:
+            assert getattr(obj.score, lang_code) is None
+
+    def test_store_string(self):
+        """Tests whether the field properly raises
+        an error when trying to store a non-float."""
+
+        for lang_code, _ in settings.LANGUAGES:
+            obj = self.TestModel()
+            with self.assertRaises(IntegrityError):
+                obj.score.set(lang_code, 'haha')
+                obj.save()
+
+    def test_none_if_illegal_value_stored(self):
+        """Tests whether None is returned for a language
+        if the value stored in the database is not an
+        float."""
+
+        obj = self.TestModel()
+        obj.score.set(settings.LANGUAGE_CODE, 25.0)
+        obj.save()
+
+        with connection.cursor() as cursor:
+            table_name = self.TestModel._meta.db_table
+            cursor.execute("update %s set score = 'en=>haha'" % table_name)
+
+        obj.refresh_from_db()
+        assert obj.score.get(settings.LANGUAGE_CODE) is None
+
+    def test_default_value(self):
+        """Tests whether a default is properly set
+        when specified."""
+
+        model = get_fake_model({
+            'score': LocalizedFloatField(default={settings.LANGUAGE_CODE: 75.0})
+        })
+
+        obj = model.objects.create()
+        assert obj.score.get(settings.LANGUAGE_CODE) == 75.0
+
+        obj = model()
+        for lang_code, _ in settings.LANGUAGES:
+            obj.score.set(lang_code, None)
+        obj.save()
+
+        for lang_code, _ in settings.LANGUAGES:
+            if lang_code == settings.LANGUAGE_CODE:
+                assert obj.score.get(lang_code) == 75.0
+            else:
+                assert obj.score.get(lang_code) is None
