reflex/reflex/utils/serializers.py
2023-12-12 14:03:40 -08:00

313 lines
7.5 KiB
Python

"""Serializers used to convert Var types to JSON strings."""
from __future__ import annotations
import json
import types as builtin_types
from datetime import date, datetime, time, timedelta
from typing import Any, Callable, Dict, List, Set, Tuple, Type, Union, get_type_hints
from reflex.base import Base
from reflex.utils import exceptions, format, types
# Mapping from type to a serializer.
# The serializer should convert the type to a JSON object.
SerializedType = Union[str, bool, int, float, list, dict]
Serializer = Callable[[Type], SerializedType]
SERIALIZERS: dict[Type, Serializer] = {}
def serializer(fn: Serializer) -> Serializer:
"""Decorator to add a serializer for a given type.
Args:
fn: The function to decorate.
Returns:
The decorated function.
Raises:
ValueError: If the function does not take a single argument.
"""
# Get the global serializers.
global SERIALIZERS
# Check the type hints to get the type of the argument.
type_hints = get_type_hints(fn)
args = [arg for arg in type_hints if arg != "return"]
# Make sure the function takes a single argument.
if len(args) != 1:
raise ValueError("Serializer must take a single argument.")
# Get the type of the argument.
type_ = type_hints[args[0]]
# Make sure the type is not already registered.
registered_fn = SERIALIZERS.get(type_)
if registered_fn is not None and registered_fn != fn:
raise ValueError(
f"Serializer for type {type_} is already registered as {registered_fn.__qualname__}."
)
# Register the serializer.
SERIALIZERS[type_] = fn
# Return the function.
return fn
def serialize(value: Any) -> SerializedType | None:
"""Serialize the value to a JSON string.
Args:
value: The value to serialize.
Returns:
The serialized value, or None if a serializer is not found.
"""
# Get the serializer for the type.
serializer = get_serializer(type(value))
# If there is no serializer, return None.
if serializer is None:
return None
# Serialize the value.
return serializer(value)
def get_serializer(type_: Type) -> Serializer | None:
"""Get the serializer for the type.
Args:
type_: The type to get the serializer for.
Returns:
The serializer for the type, or None if there is no serializer.
"""
global SERIALIZERS
# First, check if the type is registered.
serializer = SERIALIZERS.get(type_)
if serializer is not None:
return serializer
# If the type is not registered, check if it is a subclass of a registered type.
for registered_type, serializer in reversed(SERIALIZERS.items()):
if types._issubclass(type_, registered_type):
return serializer
# If there is no serializer, return None.
return None
def has_serializer(type_: Type) -> bool:
"""Check if there is a serializer for the type.
Args:
type_: The type to check.
Returns:
Whether there is a serializer for the type.
"""
return get_serializer(type_) is not None
@serializer
def serialize_type(value: type) -> str:
"""Serialize a python type.
Args:
value: the type to serialize.
Returns:
The serialized type.
"""
return value.__name__
@serializer
def serialize_str(value: str) -> str:
"""Serialize a string.
Args:
value: The string to serialize.
Returns:
The serialized string.
"""
return value
@serializer
def serialize_primitive(value: Union[bool, int, float, None]) -> str:
"""Serialize a primitive type.
Args:
value: The number/bool/None to serialize.
Returns:
The serialized number/bool/None.
"""
return format.json_dumps(value)
@serializer
def serialize_base(value: Base) -> str:
"""Serialize a Base instance.
Args:
value : The Base to serialize.
Returns:
The serialized Base.
"""
return value.json()
@serializer
def serialize_list(value: Union[List, Tuple, Set]) -> str:
"""Serialize a list to a JSON string.
Args:
value: The list to serialize.
Returns:
The serialized list.
"""
# Dump the list to a string.
fprop = format.json_dumps(list(value))
# Unwrap var values.
return format.unwrap_vars(fprop)
@serializer
def serialize_dict(prop: Dict[str, Any]) -> str:
"""Serialize a dictionary to a JSON string.
Args:
prop: The dictionary to serialize.
Returns:
The serialized dictionary.
Raises:
InvalidStylePropError: If the style prop is invalid.
"""
# Import here to avoid circular imports.
from reflex.event import EventHandler
prop_dict = {}
for key, value in prop.items():
if types._issubclass(type(value), Callable):
raise exceptions.InvalidStylePropError(
f"The style prop `{format.to_snake_case(key)}` cannot have " # type: ignore
f"`{value.fn.__qualname__ if isinstance(value, EventHandler) else value.__qualname__ if isinstance(value, builtin_types.FunctionType) else value}`, "
f"an event handler or callable as its value"
)
prop_dict[key] = value
# Dump the dict to a string.
fprop = format.json_dumps(prop_dict)
# Unwrap var values.
return format.unwrap_vars(fprop)
@serializer
def serialize_datetime(dt: Union[date, datetime, time, timedelta]) -> str:
"""Serialize a datetime to a JSON string.
Args:
dt: The datetime to serialize.
Returns:
The serialized datetime.
"""
return str(dt)
try:
from pandas import DataFrame
def format_dataframe_values(df: DataFrame) -> List[List[Any]]:
"""Format dataframe values to a list of lists.
Args:
df: The dataframe to format.
Returns:
The dataframe as a list of lists.
"""
return [
[str(d) if isinstance(d, (list, tuple)) else d for d in data]
for data in list(df.values.tolist())
]
@serializer
def serialize_dataframe(df: DataFrame) -> dict:
"""Serialize a pandas dataframe.
Args:
df: The dataframe to serialize.
Returns:
The serialized dataframe.
"""
return {
"columns": df.columns.tolist(),
"data": format_dataframe_values(df),
}
except ImportError:
pass
try:
from plotly.graph_objects import Figure
from plotly.io import to_json
@serializer
def serialize_figure(figure: Figure) -> list:
"""Serialize a plotly figure.
Args:
figure: The figure to serialize.
Returns:
The serialized figure.
"""
return json.loads(str(to_json(figure)))["data"]
except ImportError:
pass
try:
import base64
import io
from PIL.Image import Image as Img
@serializer
def serialize_image(image: Img) -> str:
"""Serialize a plotly figure.
Args:
image: The image to serialize.
Returns:
The serialized image.
"""
buff = io.BytesIO()
image.save(buff, format=getattr(image, "format", None) or "PNG")
image_bytes = buff.getvalue()
base64_image = base64.b64encode(image_bytes).decode("utf-8")
mime_type = getattr(image, "get_format_mimetype", lambda: "image/png")()
return f"data:{mime_type};base64,{base64_image}"
except ImportError:
pass