Merge branch 'master' into UPDATE_prevent_using_i18n_virt_field_as_fo…

…rm_field

docs/index.rst

@@ -24,6 +24,7 @@ Table of contents
     :caption: Documentation
 
     pages/getting-started
+    pages/working-with-models
     pages/performance
     pages/inner-workings
     pages/known-issues

docs/pages/working-with-models.rst

@@ -0,0 +1,26 @@
+Working with models recipes.
+============================
+
+Inheritance of translation models.
+----------------------------------
+
+In case when you are working with models Inheritance and you want to change
+behavior of TranslationField declared in parent model, you should use
+`i18n_field_params` attribute and declare there parameters
+for child model field.
+
+Example of use: ::
+
+    class ParentModel(models.Model):
+        info = models.CharField(max_length=255)
+
+        i18n = TranslationField(fields=("info", ), required_languages=("en",))
+
+
+    class ChildModel(ParentModel):
+        child_info = models.CharField(max_length=255)
+
+        i18n_field_params = {
+            "fields": ("info", "child_info"),
+            "required_languages": ("nl",)
+        }

modeltrans/translator.py

@@ -35,6 +35,16 @@ def get_translated_models(app_name):
             yield model
 
 
+def get_i18n_field_param(Model, i18n_field, param_name):
+    """
+    Return i18n_param from Model.i18n_field_params dict if exists
+    or get param from i18n_field
+    """
+    if hasattr(Model, "i18n_field_params") and param_name in Model.i18n_field_params:
+        return Model.i18n_field_params[param_name]
+    return getattr(i18n_field, param_name)
+
+
 def translate_model(Model):
     i18n_field = get_i18n_field(Model)
 
@@ -52,7 +62,9 @@ def translate_model(Model):
     validate(Model)
 
     add_manager(Model)
-    add_virtual_fields(Model, i18n_field.fields, i18n_field.required_languages)
+    fields_to_translate = get_i18n_field_param(Model, i18n_field, "fields")
+    required_languages = get_i18n_field_param(Model, i18n_field, "required_languages")
+    add_virtual_fields(Model, fields_to_translate, required_languages)
     patch_constructor(Model)
 
     translate_meta_ordering(Model)

tests/app/models.py

@@ -158,3 +158,12 @@ class Meta:
 class Article(AbstractArticle):
 
     pass
+
+
+class ChildArticle(Article):
+    """
+    Child Article for Django Models Inheritance testing
+    """
+
+    child_title = models.CharField(max_length=255)
+    i18n_field_params = {"fields": ["title", "child_title"], "required_languages": ("nl",)}

tests/test_models.py

@@ -8,7 +8,7 @@
 from django.utils.translation import override
 
 from modeltrans.fields import TranslationField
-from tests.app.models import Blog, NullableTextModel, TextModel
+from tests.app.models import Article, Blog, ChildArticle, NullableTextModel, TextModel
 
 from .utils import CreateTestModel
 
@@ -268,6 +268,33 @@ def test_defer_i18n(self):
             blog.title_i18n
 
 
+class TranslatedFieldInheritanceTest(TestCase):
+    def test_child_model_i18n_fields(self):
+        self.assertFalse(hasattr(Article, "child_title_nl"))
+        self.assertTrue(hasattr(ChildArticle, "child_title_nl"))
+
+    def test_child_model_required_languages(self):
+        self.assertTrue(Article._meta.get_field("title_nl").blank)
+        self.assertFalse(ChildArticle._meta.get_field("title_nl").blank)
+
+    def test_diff_i18n_parent_child_models_instances(self):
+        """
+        Test different behavior of Article and ChildArticle instances
+        """
+        article = Article(title="Title")
+        article.full_clean()
+        article.save()
+        child_article = ChildArticle(title="Title", child_title="Child title")
+        with self.assertRaises(ValidationError):
+            child_article.full_clean()
+        child_article.title_nl = "Title NL"
+        child_article.child_title_nl = "Child title NL"
+        child_article.full_clean()
+        child_article.save()
+        self.assertFalse("child_title_nl" in article.i18n)
+        self.assertTrue("child_title_nl" in child_article.i18n)
+
+
 class RefreshFromDbTest(TestCase):
     def test_refresh_from_db(self):
         b = Blog.objects.create(title="Falcon", i18n={"title_nl": "Valk", "title_de": "Falk"})

tests/test_translating.py

@@ -38,6 +38,7 @@ def test_get_translated_models(self):
         expected = {
             app_models.Article,
             app_models.Blog,
+            app_models.ChildArticle,
             app_models.Category,
             app_models.Person,
             app_models.TextModel,

tox.ini

@@ -20,6 +20,11 @@ basepython =
     py35: python3.5
     py36: python3.6
     py37: python3.7
+
+# workaround for Error installing '...django-tables2': editable mode is not supported for pyproject.toml-style projects.
+# https://github.com/pypa/pip/issues/6434
+install_command = python -m pip install --no-use-pep517 {opts} {packages}
+
 usedevelop = true
 pip_pre = true
 setenv =