Feature/allow renaming expandable foreign keys

.bumpversion.cfg

@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.20.0
+current_version = 0.21.0
 
 [bumpversion:file:setup.py]
 

CHANGELOG.md

@@ -6,7 +6,9 @@ and this project adheres to [Semantic
 Versioning](https://semver.org/spec/v2.0.0.html).
 
 
-# [Unrelased]
+# [0.21.0]
+### Added
+- [PR 42](/~https://github.com/salesforce/django-declarative-apis/pull/42) Add inst_field_name to expandable fields
 ### Changed
 - [PR 39](/~https://github.com/salesforce/django-declarative-apis/pull/39) Add long_description to setup 
 - [PR 40](/~https://github.com/salesforce/django-declarative-apis/pull/40) Remove use of root logger

django_declarative_apis/machinery/filtering.py

@@ -21,40 +21,44 @@
 
 
 class _ExpandableForeignKey:
-    def __init__(self, display_key, model_class):
+    def __init__(self, display_key, model_class, inst_field_name):
         self.display_key = display_key
         self.model_class = model_class
+        self.inst_field_name = inst_field_name
 
 
-def expandable(model_class=None, display_key=None):
+def expandable(model_class=None, display_key=None, inst_field_name=None):
     if model_class and not issubclass(model_class, (models.Model,)):
         raise ValueError("model_class must be an instance of a Django Model")
     if model_class and display_key:
         try:
             model_class._meta.get_field(display_key)
         except models.FieldDoesNotExist as e:  # noqa
             raise ValueError(f"{display_key} is not a field on {model_class.__name__}")
-    return _ExpandableForeignKey(display_key, model_class)
+    return _ExpandableForeignKey(display_key, model_class, inst_field_name)
 
 
 def _get_unexpanded_field_value(inst, field_name, field_type):
     if not field_type.model_class:
         return DEFAULT_UNEXPANDED_VALUE
 
     display_key = field_type.display_key or field_type.model_class._meta.pk.name
-    is_multiple = isinstance(inst.__class__._meta.get_field(field_name), ManyToOneRel)
+    inst_field_name = field_type.inst_field_name or field_name
+    is_multiple = isinstance(
+        inst.__class__._meta.get_field(inst_field_name), ManyToOneRel
+    )
 
     if is_multiple:
         # special case for keys that have multiple values (for instance, inverse fk relations)
-        obj = getattr(inst, field_name)
+        obj = getattr(inst, inst_field_name)
         return [{display_key: getattr(v, display_key)} for v in obj.all()]
 
     if display_key == field_type.model_class._meta.pk.name:
         # special case - we know this is a primary key, so we can get it without retrieving the object
-        return {display_key: getattr(inst, field_name + "_id")}
+        return {display_key: getattr(inst, inst_field_name + "_id")}
     else:
         # we're not returning the PK - have to actually retrieve the model
-        obj = getattr(inst, field_name)
+        obj = getattr(inst, inst_field_name)
         return {display_key: getattr(obj, display_key)}
 
 
@@ -67,8 +71,12 @@ def _get_filtered_field_value(
 
     if isinstance(field_type, types.FunctionType):
         val = field_type(inst)
-    elif isinstance(field_type, _ExpandableForeignKey) and not expand_this:
-        val = _get_unexpanded_field_value(inst, field_name, field_type)
+    elif isinstance(field_type, _ExpandableForeignKey):
+        if expand_this:
+            inst_field_name = field_type.inst_field_name or field_name
+            val = getattr(inst, inst_field_name)
+        else:
+            val = _get_unexpanded_field_value(inst, field_name, field_type)
     else:
         try:
             val = getattr(inst, field_name)

setup.py

@@ -20,7 +20,7 @@
 
 setuptools.setup(
     name="django-declarative-apis",
-    version="0.20.0",  # set by bumpversion
+    version="0.21.0",  # set by bumpversion
     author="Drew Shafer",
     url="https://salesforce.com",
     description="Simple, readable, declarative APIs for Django",

tests/filters.py

@@ -38,6 +38,34 @@
     },
 }
 
+RENAMED_EXPANDABLE_MODEL_FIELDS = {
+    str: ALWAYS,
+    int: ALWAYS,
+    dict: ALWAYS,
+    models.TestModel: {
+        "pk": ALWAYS,
+        "int_field": ALWAYS,
+        "renamed_expandable_dict": expandable(inst_field_name="expandable_dict"),
+        "renamed_expandable_string": expandable(inst_field_name="expandable_string"),
+    },
+    models.ParentModel: {
+        "nonstandard_id": ALWAYS,
+        "name": ALWAYS,
+        "favorite": expandable(model_class=models.ChildModel, display_key="name"),
+        "children": expandable(model_class=models.ChildModel, display_key="name"),
+    },
+    models.ChildModel: {
+        "pk": ALWAYS,
+        "renamed_test": expandable(
+            model_class=models.TestModel, inst_field_name="test"
+        ),
+        "name": ALWAYS,
+        "renamed_parent": expandable(
+            model_class=models.ParentModel, inst_field_name="parent"
+        ),
+    },
+}
+
 DEFAULT_FILTERS_NO_EXPANDABLE = {
     str: ALWAYS,
     int: ALWAYS,

tests/test_filters.py

@@ -180,3 +180,45 @@ def test_expandable_absent_if_no_expandable_fields(self):
         self.assertEqual(
             filtered["expandable_string"], models.TestModel.EXPANDABLE_STRING_RETURN
         )
+
+    def test_rename_expandable_foreign_key(self):
+        filtered = filtering.apply_filters_to_object(
+            self.p1c1, filters.RENAMED_EXPANDABLE_MODEL_FIELDS
+        )
+
+        self.assertEqual(filtered["renamed_test"], {"id": self.p1c1.test.pk})
+        self.assertEqual(
+            filtered["renamed_parent"], {"nonstandard_id": self.p1c1.parent.pk}
+        )
+
+        filtered = filtering.apply_filters_to_object(
+            self.p1c1,
+            filters.RENAMED_EXPANDABLE_MODEL_FIELDS,
+            expand_header="renamed_test,renamed_parent",
+        )
+        self.assertTrue(2, len(filtered["renamed_test"]))
+        self.assertIn("int_field", filtered["renamed_test"])
+        self.assertNotIn("renamed_expandable_dict", filtered["renamed_test"])
+        self.assertTrue(4, len(filtered["renamed_parent"]))
+
+        filtered = filtering.apply_filters_to_object(
+            self.p1c1,
+            filters.RENAMED_EXPANDABLE_MODEL_FIELDS,
+            expand_header="renamed_test,renamed_test.renamed_expandable_dict",
+        )
+        self.assertTrue(3, len(filtered["renamed_test"]))
+        self.assertIn("renamed_expandable_dict", filtered["renamed_test"])
+        self.assertEqual(
+            self.test_model.expandable_dict,
+            filtered["renamed_test"]["renamed_expandable_dict"],
+        )
+        self.assertNotIn("renamed_expandable_string", filtered["renamed_test"])
+
+        filtered = filtering.apply_filters_to_object(
+            self.p1c1,
+            filters.RENAMED_EXPANDABLE_MODEL_FIELDS,
+            expand_header="renamed_test,renamed_test.renamed_expandable_dict,renamed_test.renamed_expandable_string",
+        )
+        self.assertTrue(4, len(filtered["renamed_test"]))
+        self.assertIn("renamed_expandable_dict", filtered["renamed_test"])
+        self.assertIn("renamed_expandable_string", filtered["renamed_test"])