Merge pull request #143 from developmentseed/CustomSerializer

add custom serializer to match GeoJSON spec

Author: vincentsarago

CHANGELOG.md

@@ -19,6 +19,8 @@ Note: Minor version `0.X.0` update might break the API, It's recommanded to pin
 
 ### Changed
 
+* update pydantic requirement to `~=2.0`
+
 * update pydantic `FeatureCollection` generic model to allow named features in the generated schemas.
 
     ```python
@@ -29,8 +31,6 @@ Note: Minor version `0.X.0` update might break the API, It's recommanded to pin
     FeatureCollection[Feature[Geometry, Properties]]
     ```
 
-* update pydantic requirement to `~=2.0`
-
 * raise `ValueError` in `geomtries.parse_geometry_obj` instead of `ValidationError`
 
     ```python
@@ -43,6 +43,19 @@ Note: Minor version `0.X.0` update might break the API, It's recommanded to pin
     >> ValueError("Unknown type: This type")
     ```
 
+* update JSON serializer to exclude null `bbox` and `id`
+
+    ```python
+    # before
+    Point(type="Point", coordinates=[0, 0]).json()
+    >> '{"type":"Point","coordinates":[0.0,0.0],"bbox":null}'
+
+    # now
+    Point(type="Point", coordinates=[0, 0]).model_dump_json()
+    >> '{"type":"Point","coordinates":[0.0,0.0]}'
+    ```
+
+
 ## [0.6.3] - 2023-07-02
 
 * limit pydantic requirement to `~=1.0`

geojson_pydantic/base.py

@@ -0,0 +1,68 @@
+"""pydantic BaseModel for GeoJSON objects."""
+from __future__ import annotations
+
+from typing import Any, Dict, List, Optional, Set
+
+from pydantic import BaseModel, SerializationInfo, field_validator, model_serializer
+
+from geojson_pydantic.types import BBox
+
+
+class _GeoJsonBase(BaseModel):
+    bbox: Optional[BBox] = None
+
+    # These fields will not be included when serializing in json mode
+    # `.model_dump_json()` or `.model_dump(mode="json")`
+    __geojson_exclude_if_none__: Set[str] = {"bbox"}
+
+    @property
+    def __geo_interface__(self) -> Dict[str, Any]:
+        """GeoJSON-like protocol for geo-spatial (GIS) vector data.
+
+        ref: https://gist.github.com/sgillies/2217756#__geo_interface
+        """
+        return self.model_dump(mode="json")
+
+    @field_validator("bbox")
+    def validate_bbox(cls, bbox: Optional[BBox]) -> Optional[BBox]:
+        """Validate BBox values are ordered correctly."""
+        # If bbox is None, there is nothing to validate.
+        if bbox is None:
+            return None
+
+        # A list to store any errors found so we can raise them all at once.
+        errors: List[str] = []
+
+        # Determine where the second position starts. 2 for 2D, 3 for 3D.
+        offset = len(bbox) // 2
+
+        # Check X
+        if bbox[0] > bbox[offset]:
+            errors.append(f"Min X ({bbox[0]}) must be <= Max X ({bbox[offset]}).")
+        # Check Y
+        if bbox[1] > bbox[1 + offset]:
+            errors.append(f"Min Y ({bbox[1]}) must be <= Max Y ({bbox[1 + offset]}).")
+        # If 3D, check Z values.
+        if offset > 2 and bbox[2] > bbox[2 + offset]:
+            errors.append(f"Min Z ({bbox[2]}) must be <= Max Z ({bbox[2 + offset]}).")
+
+        # Raise any errors found.
+        if errors:
+            raise ValueError("Invalid BBox. Error(s): " + " ".join(errors))
+
+        return bbox
+
+    @model_serializer(when_used="json", mode="wrap")
+    def clean_model(self, serializer: Any, _info: SerializationInfo) -> Dict[str, Any]:
+        """Custom Model serializer to match the GeoJSON specification.
+
+        Used to remove fields which are optional but cannot be null values.
+        """
+        # This seems like the best way to have the least amount of unexpected consequences.
+        # We want to avoid forcing values in `exclude_none` or `exclude_unset` which could
+        # cause issues or unexpected behavior for downstream users.
+        data: Dict[str, Any] = serializer(self)
+        for field in self.__geojson_exclude_if_none__:
+            if field in data and data[field] is None:
+                del data[field]
+        return data

geojson_pydantic/features.py

@@ -4,24 +4,22 @@
 
 from pydantic import BaseModel, Field, StrictInt, StrictStr, field_validator
 
-from geojson_pydantic.geo_interface import GeoInterfaceMixin
+from geojson_pydantic.base import _GeoJsonBase
 from geojson_pydantic.geometries import Geometry
-from geojson_pydantic.types import BBox, validate_bbox
 
 Props = TypeVar("Props", bound=Union[Dict[str, Any], BaseModel])
 Geom = TypeVar("Geom", bound=Geometry)
 
 
-class Feature(BaseModel, Generic[Geom, Props], GeoInterfaceMixin):
+class Feature(_GeoJsonBase, Generic[Geom, Props]):
     """Feature Model"""
 
     type: Literal["Feature"]
     geometry: Union[Geom, None] = Field(...)
     properties: Union[Props, None] = Field(...)
     id: Optional[Union[StrictInt, StrictStr]] = None
-    bbox: Optional[BBox] = None
 
-    _validate_bbox = field_validator("bbox")(validate_bbox)
+    __geojson_exclude_if_none__ = {"bbox", "id"}
 
     @field_validator("geometry", mode="before")
     def set_geometry(cls, geometry: Any) -> Any:
@@ -35,12 +33,11 @@ def set_geometry(cls, geometry: Any) -> Any:
 Feat = TypeVar("Feat", bound=Feature)
 
 
-class FeatureCollection(BaseModel, Generic[Feat], GeoInterfaceMixin):
+class FeatureCollection(_GeoJsonBase, Generic[Feat]):
     """FeatureCollection Model"""
 
     type: Literal["FeatureCollection"]
     features: List[Feat]
-    bbox: Optional[BBox] = None
 
     def __iter__(self) -> Iterator[Feat]:  # type: ignore [override]
         """iterate over features"""
@@ -53,5 +50,3 @@ def __len__(self) -> int:
     def __getitem__(self, index: int) -> Feat:
         """get feature at a given index"""
         return self.features[index]
-
-    _validate_bbox = field_validator("bbox")(validate_bbox)

geojson_pydantic/geo_interface.py

@@ -3,22 +3,20 @@
 
 import abc
 import warnings
-from typing import Any, Iterator, List, Literal, Optional, Union
+from typing import Any, Iterator, List, Literal, Union
 
-from pydantic import BaseModel, Field, field_validator
+from pydantic import Field, field_validator
 from typing_extensions import Annotated
 
-from geojson_pydantic.geo_interface import GeoInterfaceMixin
+from geojson_pydantic.base import _GeoJsonBase
 from geojson_pydantic.types import (
-    BBox,
     LinearRing,
     LineStringCoords,
     MultiLineStringCoords,
     MultiPointCoords,
     MultiPolygonCoords,
     PolygonCoords,
     Position,
-    validate_bbox,
 )
 
 
@@ -72,12 +70,11 @@ def _polygons_wkt_coordinates(
     )
 
 
-class _GeometryBase(BaseModel, abc.ABC, GeoInterfaceMixin):
+class _GeometryBase(_GeoJsonBase, abc.ABC):
     """Base class for geometry models"""
 
     type: str
     coordinates: Any
-    bbox: Optional[BBox] = None
 
     @abc.abstractmethod
     def __wkt_coordinates__(self, coordinates: Any, force_z: bool) -> str:
@@ -107,8 +104,6 @@ def wkt(self) -> str:
 
         return wkt
 
-    _validate_bbox = field_validator("bbox")(validate_bbox)
-
 
 class Point(_GeometryBase):
     """Point Model"""
@@ -249,12 +244,11 @@ def check_closure(cls, coordinates: List) -> List:
         return coordinates
 
 
-class GeometryCollection(BaseModel, GeoInterfaceMixin):
+class GeometryCollection(_GeoJsonBase):
     """GeometryCollection Model"""
 
     type: Literal["GeometryCollection"]
     geometries: List[Geometry]
-    bbox: Optional[BBox] = None
 
     def __iter__(self) -> Iterator[Geometry]:  # type: ignore [override]
         """iterate over geometries"""
@@ -286,8 +280,6 @@ def wkt(self) -> str:
         z = " Z " if "Z" in geometries else " "
         return f"{self.type.upper()}{z}{geometries}"
 
-    _validate_bbox = field_validator("bbox")(validate_bbox)
-
     @field_validator("geometries")
     def check_geometries(cls, geometries: List) -> List:
         """Add warnings for conditions the spec does not explicitly forbid."""

geojson_pydantic/geometries.py

@@ -1,47 +1,15 @@
 """Types for geojson_pydantic models"""
 
-from typing import List, Optional, Tuple, TypeVar, Union
+from typing import List, Tuple, Union
 
 from pydantic import Field
 from typing_extensions import Annotated
 
-T = TypeVar("T")
-
 BBox = Union[
     Tuple[float, float, float, float],  # 2D bbox
     Tuple[float, float, float, float, float, float],  # 3D bbox
 ]
 
-
-def validate_bbox(bbox: Optional[BBox]) -> Optional[BBox]:
-    """Validate BBox values are ordered correctly."""
-    # If bbox is None, there is nothing to validate.
-    if bbox is None:
-        return None
-
-    # A list to store any errors found so we can raise them all at once.
-    errors: List[str] = []
-
-    # Determine where the second position starts. 2 for 2D, 3 for 3D.
-    offset = len(bbox) // 2
-
-    # Check X
-    if bbox[0] > bbox[offset]:
-        errors.append(f"Min X ({bbox[0]}) must be <= Max X ({bbox[offset]}).")
-    # Check Y
-    if bbox[1] > bbox[1 + offset]:
-        errors.append(f"Min Y ({bbox[1]}) must be <= Max Y ({bbox[1 + offset]}).")
-    # If 3D, check Z values.
-    if offset > 2 and bbox[2] > bbox[2 + offset]:
-        errors.append(f"Min Z ({bbox[2]}) must be <= Max Z ({bbox[2 + offset]}).")
-
-    # Raise any errors found.
-    if errors:
-        raise ValueError("Invalid BBox. Error(s): " + " ".join(errors))
-
-    return bbox
-
-
 Position = Union[Tuple[float, float], Tuple[float, float, float]]
 
 # Coordinate arrays

geojson_pydantic/types.py

@@ -88,6 +88,4 @@ ignore = [
 ]
 
 [tool.ruff.per-file-ignores]
-"tests/test_geometries.py" = ["D1"]
-"tests/test_features.py" = ["D1"]
-"tests/test_package.py" = ["D1"]
+"tests/*.py" = ["D1"]