Add placeholders URLs to low level API and contrib DRF

pictures/models.py

@@ -11,10 +11,12 @@
 from django.core.files.storage import Storage
 from django.db.models import ImageField
 from django.db.models.fields.files import ImageFieldFile
+from django.urls import reverse
 from PIL import Image, ImageOps
 
 __all__ = ["PictureField", "PictureFieldFile"]
 
+
 from pictures import conf, utils
 
 
@@ -33,6 +35,18 @@ def __post_init__(self):
 
     @property
     def url(self) -> str:
+        if conf.get_settings().USE_PLACEHOLDERS:
+            return reverse(
+                "pictures:placeholder",
+                kwargs={
+                    "alt": Path(self.parent_name).stem,
+                    "width": self.width,
+                    "ratio": f"{self.aspect_ratio.numerator}x{self.aspect_ratio.denominator}"
+                    if self.aspect_ratio
+                    else None,
+                    "file_type": self.file_type,
+                },
+            )
         return self.storage.url(self.name)
 
     @property

tests/contrib/test_rest_framework.py

@@ -18,7 +18,8 @@ class Meta:
         fields = ["picture"]
 
 
-def test_default():
+def test_default(settings):
+    settings.PICTURES["USE_PLACEHOLDERS"] = False
     assert (
         rest_framework.default(
             obj=SimplePicture(
@@ -41,7 +42,8 @@ def test_default__type_error():
 
 class TestPictureField:
     @pytest.mark.django_db
-    def test_to_representation(self, image_upload_file):
+    def test_to_representation(self, image_upload_file, settings):
+        settings.PICTURES["USE_PLACEHOLDERS"] = False
 
         profile = models.Profile.objects.create(picture=image_upload_file)
         serializer = ProfileSerializer(profile)

tests/test_models.py

@@ -37,12 +37,17 @@ class TestSimplePicture:
         width=800,
     )
 
-    def test_url(self):
+    def test_url(self, settings):
+        settings.PICTURES["USE_PLACEHOLDERS"] = False
         assert (
             self.picture_with_ratio.url
             == "/media/testapp/simplemodel/image/4_3/800w.webp"
         )
 
+    def test_url__placeholder(self, settings):
+        settings.PICTURES["USE_PLACEHOLDERS"] = True
+        assert self.picture_with_ratio.url == "/_pictures/image/4x3/800w.WEBP"
+
     def test_height(self):
         assert self.picture_with_ratio.height == 600
         assert not self.picture_without_ratio.height