Support for slugging from multiple fields

localized_fields/fields/autoslug_field.py

@@ -1,12 +1,14 @@
-from typing import Callable, Tuple
+from typing import Callable, Tuple, Union
 from datetime import datetime
 
 from django import forms
 from django.conf import settings
+from django.utils import translation
 from django.utils.text import slugify
 
 from .field import LocalizedField
 from ..value import LocalizedValue
+from ..util import resolve_object_property
 
 
 class LocalizedAutoSlugField(LocalizedField):
@@ -147,7 +149,7 @@ class LocalizedAutoSlugField(LocalizedField):
         ]
 
     @staticmethod
-    def _get_populate_from_value(instance, field_name: str, language: str):
+    def _get_populate_from_value(instance, field_name: Union[str, Tuple[str]], language: str):
         """Gets the value to create a slug from in the specified language.
 
         Arguments:
@@ -164,5 +166,17 @@ class LocalizedAutoSlugField(LocalizedField):
             The text to generate a slug for.
         """
 
-        value = getattr(instance, field_name, None)
-        return value.get(language)
+        def get_field_value(name):
+            value = resolve_object_property(instance, name)
+            with translation.override(language):
+                return str(value)
+
+        if isinstance(field_name, tuple) or isinstance(field_name, list):
+            value = '-'.join([
+                value
+                for value in [get_field_value(name) for name in field_name]
+                if value
+            ])
+            return value
+
+        return get_field_value(field_name)

localized_fields/util.py

@@ -19,3 +19,26 @@ def get_language_codes() -> List[str]:
         lang_code
         for lang_code, _ in settings.LANGUAGES
     ]
+
+
+def resolve_object_property(obj, path: str):
+    """Resolves the value of a property on an object.
+
+    Is able to resolve nested properties. For example,
+    a path can be specified:
+
+        'other.beer.name'
+
+    Raises:
+        AttributeError:
+            In case the property could not be resolved.
+
+    Returns:
+        The value of the specified property.
+    """
+
+    value = obj
+    for path_part in path.split('.'):
+        value = getattr(value, path_part)
+
+    return value

tests/test_slug_fields.py

@@ -1,6 +1,7 @@
 import copy
 
 from django import forms
+from django.db import models
 from django.conf import settings
 from django.test import TestCase
 from django.db.utils import IntegrityError
@@ -31,6 +32,7 @@ class LocalizedSlugFieldTestCase(TestCase):
             'LocalizedAutoSlugFieldTestModel',
             {
                 'title': LocalizedField(),
+                'name': models.CharField(max_length=255),
                 'slug': LocalizedAutoSlugField(populate_from='title')
             }
         )
@@ -39,6 +41,7 @@ class LocalizedSlugFieldTestCase(TestCase):
             'LocalizedUniqueSlugFieldTestModel',
             {
                 'title': LocalizedField(),
+                'name': models.CharField(max_length=255),
                 'slug': LocalizedUniqueSlugField(populate_from='title')
             }
         )
@@ -155,6 +158,22 @@ class LocalizedSlugFieldTestCase(TestCase):
     def test_formfield_unique(cls):
         cls._test_formfield(LocalizedUniqueSlugField)
 
+    @classmethod
+    def test_populate_multiple_from_fields_auto(cls):
+        cls._test_populate_multiple_from_fields(LocalizedAutoSlugField)
+
+    @classmethod
+    def test_populate_multiple_from_fields_unique(cls):
+        cls._test_populate_multiple_from_fields(LocalizedUniqueSlugField)
+
+    @classmethod
+    def test_populate_multiple_from_fields_fk_auto(cls):
+        cls._test_populate_multiple_from_fields_fk(LocalizedAutoSlugField)
+
+    @classmethod
+    def test_populate_multiple_from_fields_fk_unique(cls):
+        cls._test_populate_multiple_from_fields_fk(LocalizedUniqueSlugField)
+
     @staticmethod
     def _test_populate(model):
         """Tests whether the populating feature works correctly."""
@@ -165,6 +184,67 @@ class LocalizedSlugFieldTestCase(TestCase):
 
         assert obj.slug.get('en') == slugify(obj.title)
 
+    @staticmethod
+    def _test_populate_multiple_from_fields(field_type):
+        """Tests whether populating the slug from multiple
+        fields works correctly."""
+
+        model = get_fake_model(
+            '_test_populate_multiple_from_fields_' + str(field_type),
+            {
+                'title': LocalizedField(),
+                'name': models.CharField(max_length=255),
+                'slug': field_type(populate_from=('title', 'name'))
+            }
+        )
+
+        obj = model()
+        for lang_code, lang_name in settings.LANGUAGES:
+            obj.name = 'swen'
+            obj.title.set(lang_code, 'title %s' % lang_name)
+
+        obj.save()
+
+        for lang_code, lang_name in settings.LANGUAGES:
+            assert obj.slug.get(lang_code) == 'title-%s-swen' % lang_name.lower()
+
+    @staticmethod
+    def _test_populate_multiple_from_fields_fk(field_type):
+        """Tests whether populating the slug from multiple
+        fields works correctly."""
+
+        model_fk = get_fake_model(
+            '_test_populate_multiple_from_fields_fk_other_' + str(field_type),
+            {
+                'name': LocalizedField(),
+            }
+        )
+
+        model = get_fake_model(
+            '_test_populate_multiple_from_fields_fk_' + str(field_type),
+            {
+                'title': LocalizedField(),
+                'other': models.ForeignKey(model_fk),
+                'slug': field_type(populate_from=('title', 'other.name'))
+            }
+        )
+
+        other = model_fk.objects.create(name={settings.LANGUAGE_CODE: 'swen'})
+        # for lang_code, lang_name in settings.LANGUAGES:
+        #     other.name.set(lang_code, 'swen')
+
+        # other.save()
+
+        obj = model()
+        for lang_code, lang_name in settings.LANGUAGES:
+            obj.other_id = other.id
+            obj.title.set(lang_code, 'title %s' % lang_name)
+
+        obj.save()
+
+        for lang_code, lang_name in settings.LANGUAGES:
+            assert obj.slug.get(lang_code) == 'title-%s-swen' % lang_name.lower()
+
     @staticmethod
     def _test_populate_multiple_languages(model):
         """Tests whether the populating feature correctly