Update PictureField to support multiple aspect_ratios and file_types

Author: codingjoe

README.md

@@ -246,15 +246,15 @@ class PictureSerializer(serializers.Serializer):
     picture = PictureField()
 ```
 
-The response can be restricted to a single aspect ratio and image source, by
-providing the `aspect_ratio` and `image_source` arguments to the field.
+The response can be restricted to a fewer aspect ratios and file types, by
+providing the `aspect_ratios` and `file_types` arguments to the DRF field.
 
 ```python
 from rest_framework import serializers
 from pictures.contrib.rest_framework import PictureField
 
 class PictureSerializer(serializers.Serializer):
-    picture = PictureField(aspect_ratio="16/9", image_source="WEBP")
+    picture = PictureField(aspect_ratios=["16/9"], file_types=["WEBP"])
 ```
 
 You also may provide optional GET parameters to the serializer,

pictures/contrib/rest_framework.py

@@ -19,10 +19,10 @@ def default(obj):
 class PictureField(serializers.ReadOnlyField):
     """Read-only field for all aspect ratios and sizes of the image."""
 
-    def __init__(self, aspect_ratio=None, image_source=None, **kwargs):
-        self.aspect_ratio = aspect_ratio
-        self.image_source = image_source
+    def __init__(self, aspect_ratios=None, file_types=None, **kwargs):
         super().__init__(**kwargs)
+        self.aspect_ratios = aspect_ratios or []
+        self.file_types = file_types or []
 
     def to_representation(self, obj: PictureFieldFile):
         if not obj:
@@ -34,35 +34,20 @@ def to_representation(self, obj: PictureFieldFile):
             "height": obj.height,
         }
 
-        # if aspect_ratio is set, only return that aspect ratio to reduce payload size
-        if self.aspect_ratio and self.image_source:
-            try:
-                sizes = obj.aspect_ratios[self.aspect_ratio][self.image_source]
-            except KeyError as e:
-                raise ValueError(
-                    f"Invalid ratio {self.aspect_ratio} or image source {self.image_source}. Choices are: {', '.join(filter(None, obj.aspect_ratios.keys()))}"
-                ) from e
-            payload = {
-                **base_payload,
-                "ratios": {
-                    self.aspect_ratio: {
-                        "sources": {f"image/{self.image_source.lower()}": sizes}
-                    }
-                },
-            }
-        else:
-            payload = {
-                **base_payload,
-                "ratios": {
-                    ratio: {
-                        "sources": {
-                            f"image/{file_type.lower()}": sizes
-                            for file_type, sizes in sources.items()
-                        },
-                    }
-                    for ratio, sources in obj.aspect_ratios.items()
-                },
-            }
+        payload = {
+            **base_payload,
+            "ratios": {
+                ratio: {
+                    "sources": {
+                        f"image/{file_type.lower()}": sizes
+                        for file_type, sizes in sources.items()
+                        if file_type in self.file_types or not self.file_types
+                    },
+                }
+                for ratio, sources in obj.aspect_ratios.items()
+                if ratio in self.aspect_ratios or not self.aspect_ratios
+            },
+        }
 
         # if the request has query parameters, filter the payload
         try:

tests/contrib/test_rest_framework.py

@@ -13,7 +13,7 @@
 class ProfileSerializer(serializers.ModelSerializer):
     image = rest_framework.PictureField(source="picture")
     image_mobile = rest_framework.PictureField(
-        source="picture", aspect_ratio="3/2", image_source="WEBP"
+        source="picture", aspect_ratios=["3/2"], file_types=["WEBP"]
     )
 
     class Meta:
@@ -23,7 +23,7 @@ class Meta:
 
 class ProfileSerializerWithInvalidData(serializers.ModelSerializer):
     image_invalid = rest_framework.PictureField(
-        source="picture", aspect_ratio="21/11", image_source="GIF"
+        source="picture", aspect_ratios=["21/11"], file_types=["GIF"]
     )
 
     class Meta:
@@ -308,20 +308,3 @@ def test_to_representation__with_prefiltered_aspect_ratio_and_source(
                 }
             },
         }
-
-    @pytest.mark.django_db
-    def test_to_representation__with_prefiltered_aspect_ratio_and_source__raise_value_error(
-        self, image_upload_file, settings
-    ):
-        settings.PICTURES["USE_PLACEHOLDERS"] = False
-
-        profile = models.Profile.objects.create(picture=image_upload_file)
-
-        serializer = ProfileSerializerWithInvalidData(profile)
-        with pytest.raises(ValueError) as e:
-            serializer.data["image_invalid"]
-
-        assert (
-            str(e.value)
-            == "Invalid ratio 21/11 or image source GIF. Choices are: 1/1, 3/2, 16/9"
-        )