add datetime var comparison operations

reflex/vars/__init__.py

@@ -9,6 +9,7 @@
 from .base import get_uuid_string_var as get_uuid_string_var
 from .base import var_operation as var_operation
 from .base import var_operation_return as var_operation_return
+from .datetime import DateTimeVar as DateTimeVar
 from .function import FunctionStringVar as FunctionStringVar
 from .function import FunctionVar as FunctionVar
 from .function import VarOperationCall as VarOperationCall

reflex/vars/datetime.py

@@ -0,0 +1,242 @@
+"""Immutable datetime and date vars."""
+
+from __future__ import annotations
+
+import dataclasses
+import json
+import sys
+from datetime import date, datetime
+from typing import Any, NoReturn, TypeVar, Union, overload
+
+from reflex.utils.exceptions import VarTypeError
+from reflex.vars.number import BooleanVar
+
+from .base import (
+    CustomVarOperationReturn,
+    LiteralVar,
+    Var,
+    VarData,
+    var_operation,
+    var_operation_return,
+)
+
+DATETIME_T = TypeVar("DATETIME_T", datetime, date)
+
+datetime_types = Union[datetime, date]
+
+
+def raise_var_type_error():
+    """Raise a VarTypeError.
+
+    Raises:
+        VarTypeError: Cannot compare a datetime object with a non-datetime object.
+    """
+    raise VarTypeError("Cannot compare a datetime object with a non-datetime object.")
+
+
+class DateTimeVar(Var[DATETIME_T], python_types=(datetime, date)):
+    """A variable that holds a datetime or date object."""
+
+    @overload
+    def __lt__(self, other: datetime_types) -> BooleanVar: ...
+
+    @overload
+    def __lt__(self, other: NoReturn) -> NoReturn: ...
+
+    def __lt__(self, other: Any):
+        """Less than comparison.
+
+        Args:
+            other: The other datetime to compare.
+
+        Returns:
+            The result of the comparison.
+        """
+        if not isinstance(other, DATETIME_TYPES):
+            raise_var_type_error()
+        return date_lt_operation(self, other)
+
+    @overload
+    def __le__(self, other: datetime_types) -> BooleanVar: ...
+
+    @overload
+    def __le__(self, other: NoReturn) -> NoReturn: ...
+
+    def __le__(self, other: Any):
+        """Less than or equal comparison.
+
+        Args:
+            other: The other datetime to compare.
+
+        Returns:
+            The result of the comparison.
+        """
+        if not isinstance(other, DATETIME_TYPES):
+            raise_var_type_error()
+        return date_le_operation(self, other)
+
+    @overload
+    def __gt__(self, other: datetime_types) -> BooleanVar: ...
+
+    @overload
+    def __gt__(self, other: NoReturn) -> NoReturn: ...
+
+    def __gt__(self, other: Any):
+        """Greater than comparison.
+
+        Args:
+            other: The other datetime to compare.
+
+        Returns:
+            The result of the comparison.
+        """
+        if not isinstance(other, DATETIME_TYPES):
+            raise_var_type_error()
+        return date_gt_operation(self, other)
+
+    @overload
+    def __ge__(self, other: datetime_types) -> BooleanVar: ...
+
+    @overload
+    def __ge__(self, other: NoReturn) -> NoReturn: ...
+
+    def __ge__(self, other: Any):
+        """Greater than or equal comparison.
+
+        Args:
+            other: The other datetime to compare.
+
+        Returns:
+            The result of the comparison.
+        """
+        if not isinstance(other, DATETIME_TYPES):
+            raise_var_type_error()
+        return date_ge_operation(self, other)
+
+
+@var_operation
+def date_gt_operation(lhs: Var | Any, rhs: Var | Any) -> CustomVarOperationReturn:
+    """Greater than comparison.
+
+    Args:
+        lhs: The left-hand side of the operation.
+        rhs: The right-hand side of the operation.
+
+    Returns:
+        The result of the operation.
+    """
+    return date_compare_operation(rhs, lhs, strict=True)
+
+
+@var_operation
+def date_lt_operation(lhs: Var | Any, rhs: Var | Any) -> CustomVarOperationReturn:
+    """Less than comparison.
+
+    Args:
+        lhs: The left-hand side of the operation.
+        rhs: The right-hand side of the operation.
+
+    Returns:
+        The result of the operation.
+    """
+    return date_compare_operation(lhs, rhs, strict=True)
+
+
+@var_operation
+def date_le_operation(lhs: Var | Any, rhs: Var | Any) -> CustomVarOperationReturn:
+    """Less than or equal comparison.
+
+    Args:
+        lhs: The left-hand side of the operation.
+        rhs: The right-hand side of the operation.
+
+    Returns:
+        The result of the operation.
+    """
+    return date_compare_operation(lhs, rhs)
+
+
+@var_operation
+def date_ge_operation(lhs: Var | Any, rhs: Var | Any) -> CustomVarOperationReturn:
+    """Greater than or equal comparison.
+
+    Args:
+        lhs: The left-hand side of the operation.
+        rhs: The right-hand side of the operation.
+
+    Returns:
+        The result of the operation.
+    """
+    return date_compare_operation(rhs, lhs)
+
+
+def date_compare_operation(
+    lhs: DateTimeVar[DATETIME_T] | Any,
+    rhs: DateTimeVar[DATETIME_T] | Any,
+    strict: bool = False,
+) -> CustomVarOperationReturn:
+    """Check if the value is less than the other value.
+
+    Args:
+        lhs: The left-hand side of the operation.
+        rhs: The right-hand side of the operation.
+        strict: Whether to use strict comparison.
+
+    Returns:
+        The result of the operation.
+    """
+    return var_operation_return(
+        f"({lhs} { '<' if strict else '<='} {rhs})",
+        bool,
+    )
+
+
+@dataclasses.dataclass(
+    eq=False,
+    frozen=True,
+    **{"slots": True} if sys.version_info >= (3, 10) else {},
+)
+class LiteralDatetimeVar(LiteralVar, DateTimeVar):
+    """Base class for immutable datetime and date vars."""
+
+    _var_value: datetime | date = dataclasses.field(default=datetime.now())
+
+    def json(self) -> str:
+        """Return the JSON representation of the datetime.
+
+        Returns:
+            The JSON representation of the datetime.
+        """
+        return json.dumps(self._var_value)
+
+    def __hash__(self) -> int:
+        """Calculate the hash value of the object.
+
+        Returns:
+            int: The hash value of the object.
+        """
+        return hash((self.__class__.__name__, self._var_value))
+
+    @classmethod
+    def create(cls, value: datetime | date, _var_data: VarData | None = None):
+        """Create a new instance of the class.
+
+        Args:
+            value: The value to set.
+
+        Returns:
+            LiteralDatetimeVar: The new instance of the class.
+        """
+        if isinstance(value, datetime):
+            js_expr = f"new Date({value.year}, {value.month - 1}, {value.day}, {value.hour}, {value.minute}, {value.second}, {value.microsecond})"
+        elif isinstance(value, date):
+            js_expr = f"new Date({value.year}, {value.month - 1}, {value.day})"
+        return cls(
+            _js_expr=js_expr,
+            _var_type=type(value),
+            _var_value=value,
+            _var_data=_var_data,
+        )
+
+
+DATETIME_TYPES = (datetime, date, DateTimeVar)