some stuff ig

reflex/event.py

@@ -4,16 +4,19 @@ from __future__ import annotations
 
 import dataclasses
 import inspect
+import sys
 import types
 import urllib.parse
 from base64 import b64encode
 from typing import (
     Any,
     Callable,
+    ClassVar,
     Dict,
     List,
     Optional,
     Tuple,
+    Type,
     Union,
     get_type_hints,
 )
@@ -25,8 +28,15 @@ from reflex.utils import format
 from reflex.utils.exceptions import EventFnArgMismatch, EventHandlerArgMismatch
 from reflex.utils.types import ArgsSpec, GenericType
 from reflex.vars import VarData
-from reflex.vars.base import LiteralVar, Var
+from reflex.vars.base import (
-from reflex.vars.function import FunctionStringVar, FunctionVar
+    CachedVarOperation,
+    LiteralNoneVar,
+    LiteralVar,
+    ToOperation,
+    Var,
+    cached_property_no_lock,
+)
+from reflex.vars.function import ArgsFunctionOperation, FunctionStringVar, FunctionVar
 from reflex.vars.object import ObjectVar
 
 try:
@@ -375,7 +385,7 @@ class CallableEventSpec(EventSpec):
 class EventChain(EventActionsMixin):
     """Container for a chain of events that will be executed in order."""
 
-    events: List[EventSpec] = dataclasses.field(default_factory=list)
+    events: List[Union[EventSpec, EventVar]] = dataclasses.field(default_factory=list)
 
     args_spec: Optional[Callable] = dataclasses.field(default=None)
 
@@ -1126,3 +1136,153 @@ def get_fn_signature(fn: Callable) -> inspect.Signature:
         "state", inspect.Parameter.POSITIONAL_OR_KEYWORD, annotation=Any
     )
     return signature.replace(parameters=(new_param, *signature.parameters.values()))
+
+
+class EventVar(ObjectVar):
+    pass
+
+
+@dataclasses.dataclass(
+    eq=False,
+    frozen=True,
+    **{"slots": True} if sys.version_info >= (3, 10) else {},
+)
+class LiteralEventVar(CachedVarOperation, LiteralVar, EventVar):
+    _var_value: EventSpec = dataclasses.field(default=None)  # type: ignore
+
+    @cached_property_no_lock
+    def _cached_var_name(self) -> str:
+        """The name of the var.
+
+        Returns:
+            The name of the var.
+        """
+        event_name = LiteralVar.create(
+            ".".join(
+                filter(None, format.get_event_handler_parts(self._var_value.handler))
+            )
+        )
+        event_args = LiteralVar.create(
+            {str(name): value for name, value in self._var_value.args}
+        )
+        event_client_name = LiteralVar.create(self._var_value.client_handler_name)
+        return str(
+            FunctionStringVar("Event").call(
+                event_name,
+                event_args,
+                *([event_client_name] if self._var_value.client_handler_name else []),
+            )
+        )
+
+    @classmethod
+    def create(
+        cls,
+        value: EventSpec,
+        _var_data: VarData | None = None,
+    ) -> LiteralEventVar:
+        """Create a new LiteralEventVar instance.
+
+        Args:
+            value: The value of the var.
+            _var_data: The data of the var.
+
+        Returns:
+            The created LiteralEventVar instance.
+        """
+        return cls(
+            _js_expr="",
+            _var_type=EventSpec,
+            _var_data=_var_data,
+            _var_value=value,
+        )
+
+
+class EventChainVar(FunctionVar):
+    pass
+
+
+@dataclasses.dataclass(
+    eq=False,
+    frozen=True,
+    **{"slots": True} if sys.version_info >= (3, 10) else {},
+)
+class LiteralEventChainVar(CachedVarOperation, LiteralVar, EventChainVar):
+    _var_value: EventChain = dataclasses.field(default=None)  # type: ignore
+
+    @cached_property_no_lock
+    def _cached_var_name(self) -> str:
+        """The name of the var.
+
+        Returns:
+            The name of the var.
+        """
+        sig = inspect.signature(self._var_value.args_spec)  # type: ignore
+        if sig.parameters:
+            arg_def = tuple((f"_{p}" for p in sig.parameters))
+            arg_def_expr = LiteralVar.create([Var(_js_expr=arg) for arg in arg_def])
+        else:
+            # add a default argument for addEvents if none were specified in value.args_spec
+            # used to trigger the preventDefault() on the event.
+            arg_def = ("...args",)
+            arg_def_expr = Var(_js_expr="args")
+
+        return str(
+            ArgsFunctionOperation.create(
+                arg_def,
+                FunctionStringVar.create("addEvents").call(
+                    LiteralVar.create(
+                        [LiteralVar.create(event) for event in self._var_value.events]
+                    ),
+                    arg_def_expr,
+                    LiteralVar.create(self._var_value.event_actions),
+                ),
+            )
+        )
+
+    @classmethod
+    def create(
+        cls,
+        value: EventChain,
+        _var_data: VarData | None = None,
+    ) -> LiteralEventChainVar:
+        """Create a new LiteralEventChainVar instance.
+
+        Args:
+            value: The value of the var.
+            _var_data: The data of the var.
+
+        Returns:
+            The created LiteralEventChainVar instance.
+        """
+        return cls(
+            _js_expr="",
+            _var_type=EventChain,
+            _var_data=_var_data,
+            _var_value=value,
+        )
+
+
+@dataclasses.dataclass(
+    eq=False,
+    frozen=True,
+    **{"slots": True} if sys.version_info >= (3, 10) else {},
+)
+class ToEventVarOperation(ToOperation, EventVar):
+    """Base class for immutable number vars that are the result of a number operation."""
+
+    _original: Var = dataclasses.field(default_factory=lambda: LiteralNoneVar.create())
+
+    _default_var_type: ClassVar[Type] = EventSpec
+
+
+@dataclasses.dataclass(
+    eq=False,
+    frozen=True,
+    **{"slots": True} if sys.version_info >= (3, 10) else {},
+)
+class ToEventChainVarOperation(ToOperation, EventChainVar):
+    """Base class for immutable number vars that are the result of a number operation."""
+
+    _original: Var = dataclasses.field(default_factory=lambda: LiteralNoneVar.create())
+
+    _default_var_type: ClassVar[Type] = EventChain

reflex/vars/base.py

@@ -385,6 +385,15 @@ class Var(Generic[VAR_TYPE]):
         Returns:
             The converted var.
         """
+        from reflex.event import (
+            EventChain,
+            EventChainVar,
+            EventSpec,
+            EventVar,
+            ToEventVarOperation,
+            ToEventChainVarOperation,
+        )
+
         from .function import FunctionVar, ToFunctionOperation
         from .number import (
             BooleanVar,
@@ -416,6 +425,10 @@ class Var(Generic[VAR_TYPE]):
             return self.to(BooleanVar, output)
         if fixed_output_type is None:
             return ToNoneOperation.create(self)
+        if fixed_output_type is EventSpec:
+            return self.to(EventVar, output)
+        if fixed_output_type is EventChain:
+            return self.to(EventChainVar, output)
         if issubclass(fixed_output_type, Base):
             return self.to(ObjectVar, output)
         if dataclasses.is_dataclass(fixed_output_type) and not issubclass(
@@ -453,6 +466,12 @@ class Var(Generic[VAR_TYPE]):
         if issubclass(output, StringVar):
             return ToStringOperation.create(self, var_type or str)
 
+        if issubclass(output, EventVar):
+            return ToEventVarOperation.create(self, var_type or EventSpec)
+
+        if issubclass(output, EventChainVar):
+            return ToEventChainVarOperation.create(self, var_type or EventChain)
+
         if issubclass(output, (ObjectVar, Base)):
             return ToObjectOperation.create(self, var_type or dict)
 
@@ -494,6 +513,8 @@ class Var(Generic[VAR_TYPE]):
         Raises:
             TypeError: If the type is not supported for guessing.
         """
+        from reflex.event import EventChain, EventChainVar, EventSpec, EventVar
+
         from .number import BooleanVar, NumberVar
         from .object import ObjectVar
         from .sequence import ArrayVar, StringVar
@@ -539,6 +560,10 @@ class Var(Generic[VAR_TYPE]):
             return self.to(ArrayVar, self._var_type)
         if issubclass(fixed_type, str):
             return self.to(StringVar, self._var_type)
+        if issubclass(fixed_type, EventSpec):
+            return self.to(EventVar, self._var_type)
+        if issubclass(fixed_type, EventChain):
+            return self.to(EventChainVar, self._var_type)
         if issubclass(fixed_type, Base):
             return self.to(ObjectVar, self._var_type)
         if dataclasses.is_dataclass(fixed_type):
@@ -1029,47 +1054,22 @@ class LiteralVar(Var):
         if value is None:
             return LiteralNoneVar.create(_var_data=_var_data)
 
-        from reflex.event import EventChain, EventHandler, EventSpec
+        from reflex.event import (
+            EventChain,
+            EventHandler,
+            EventSpec,
+            LiteralEventChainVar,
+            LiteralEventVar,
+        )
         from reflex.utils.format import get_event_handler_parts
 
-        from .function import ArgsFunctionOperation, FunctionStringVar
         from .object import LiteralObjectVar
 
         if isinstance(value, EventSpec):
-            event_name = LiteralVar.create(
+            return LiteralEventVar.create(value, _var_data=_var_data)
-                ".".join(filter(None, get_event_handler_parts(value.handler)))
-            )
-            event_args = LiteralVar.create(
-                {str(name): value for name, value in value.args}
-            )
-            event_client_name = LiteralVar.create(value.client_handler_name)
-            return FunctionStringVar("Event").call(
-                event_name,
-                event_args,
-                *([event_client_name] if value.client_handler_name else []),
-            )
 
         if isinstance(value, EventChain):
-            sig = inspect.signature(value.args_spec)  # type: ignore
+            return LiteralEventChainVar.create(value, _var_data=_var_data)
-            if sig.parameters:
-                arg_def = tuple((f"_{p}" for p in sig.parameters))
-                arg_def_expr = LiteralVar.create([Var(_js_expr=arg) for arg in arg_def])
-            else:
-                # add a default argument for addEvents if none were specified in value.args_spec
-                # used to trigger the preventDefault() on the event.
-                arg_def = ("...args",)
-                arg_def_expr = Var(_js_expr="args")
-
-            return ArgsFunctionOperation.create(
-                arg_def,
-                FunctionStringVar.create("addEvents").call(
-                    LiteralVar.create(
-                        [LiteralVar.create(event) for event in value.events]
-                    ),
-                    arg_def_expr,
-                    LiteralVar.create(value.event_actions),
-                ),
-            )
 
         if isinstance(value, EventHandler):
             return Var(_js_expr=".".join(filter(None, get_event_handler_parts(value))))
@@ -2126,9 +2126,16 @@ class NoneVar(Var[None]):
     """A var representing None."""
 
 
+@dataclasses.dataclass(
+    eq=False,
+    frozen=True,
+    **{"slots": True} if sys.version_info >= (3, 10) else {},
+)
 class LiteralNoneVar(LiteralVar, NoneVar):
     """A var representing None."""
 
+    _var_value: None = None
+
     def json(self) -> str:
         """Serialize the var to a JSON string.