"""Base component definitions.""" from __future__ import annotations import contextlib import copy import dataclasses import functools import inspect import sys import typing from abc import ABC, ABCMeta, abstractmethod from collections.abc import Callable, Iterator, Mapping, Sequence from dataclasses import _MISSING_TYPE, MISSING from functools import wraps from hashlib import md5 from types import SimpleNamespace from typing import ( TYPE_CHECKING, Annotated, Any, ClassVar, ForwardRef, Generic, TypeVar, _eval_type, # pyright: ignore [reportAttributeAccessIssue] cast, get_args, get_origin, ) from rich.markup import escape from typing_extensions import dataclass_transform import reflex.state from reflex.compiler.templates import STATEFUL_COMPONENT from reflex.components.core.breakpoints import Breakpoints from reflex.components.dynamic import load_dynamic_serializer from reflex.components.tags import Tag from reflex.constants import ( Dirs, EventTriggers, Hooks, Imports, MemoizationDisposition, MemoizationMode, PageNames, ) from reflex.constants.compiler import SpecialAttributes from reflex.constants.state import FRONTEND_EVENT_STATE from reflex.event import ( EventCallback, EventChain, EventHandler, EventSpec, no_args_event_spec, parse_args_spec, run_script, unwrap_var_annotation, ) from reflex.style import Style, format_as_emotion from reflex.utils import console, format, imports, types from reflex.utils.imports import ImportDict, ImportVar, ParsedImportDict, parse_imports from reflex.vars import VarData from reflex.vars.base import ( CachedVarOperation, LiteralNoneVar, LiteralVar, Var, cached_property_no_lock, ) from reflex.vars.function import ArgsFunctionOperation, FunctionStringVar, FunctionVar from reflex.vars.number import ternary_operation from reflex.vars.object import LiteralObjectVar, ObjectVar from reflex.vars.sequence import LiteralArrayVar, LiteralStringVar, StringVar def resolve_annotations( raw_annotations: Mapping[str, type[Any]], module_name: str | None ) -> dict[str, type[Any]]: """Partially taken from typing.get_type_hints. Resolve string or ForwardRef annotations into type objects if possible. Args: raw_annotations: The raw annotations to resolve. module_name: The name of the module. Returns: The resolved annotations. """ module = sys.modules.get(module_name, None) if module_name is not None else None base_globals: dict[str, Any] | None = ( module.__dict__ if module is not None else None ) annotations = {} for name, value in raw_annotations.items(): if isinstance(value, str): if sys.version_info == (3, 10, 0): value = ForwardRef(value, is_argument=False) else: value = ForwardRef(value, is_argument=False, is_class=True) try: if sys.version_info >= (3, 13): value = _eval_type(value, base_globals, None, type_params=()) else: value = _eval_type(value, base_globals, None) except NameError: # this is ok, it can be fixed with update_forward_refs pass annotations[name] = value return annotations FIELD_TYPE = TypeVar("FIELD_TYPE") class ComponentField(Generic[FIELD_TYPE]): """A field for a component.""" def __init__( self, default: FIELD_TYPE | _MISSING_TYPE = MISSING, default_factory: Callable[[], FIELD_TYPE] | None = None, is_javascript: bool | None = None, annotated_type: type[Any] | _MISSING_TYPE = MISSING, ) -> None: """Initialize the field. Args: default: The default value for the field. default_factory: The default factory for the field. is_javascript: Whether the field is a javascript property. annotated_type: The annotated type for the field. """ self.default = default self.default_factory = default_factory self.is_javascript = is_javascript self.outer_type_ = self.annotated_type = annotated_type type_origin = get_origin(annotated_type) or annotated_type if type_origin is Annotated: type_origin = annotated_type.__origin__ # pyright: ignore [reportAttributeAccessIssue] self.type_ = self.type_origin = type_origin def default_value(self) -> FIELD_TYPE: """Get the default value for the field. Returns: The default value for the field. Raises: ValueError: If no default value or factory is provided. """ if self.default is not MISSING: return self.default if self.default_factory is not None: return self.default_factory() raise ValueError("No default value or factory provided.") def __repr__(self) -> str: """Represent the field in a readable format. Returns: The string representation of the field. """ annotated_type_str = ( f", annotated_type={self.annotated_type!r}" if self.annotated_type is not MISSING else "" ) if self.default is not MISSING: return f"ComponentField(default={self.default!r}, is_javascript={self.is_javascript!r}{annotated_type_str})" return f"ComponentField(default_factory={self.default_factory!r}, is_javascript={self.is_javascript!r}{annotated_type_str})" def field( default: FIELD_TYPE | _MISSING_TYPE = MISSING, default_factory: Callable[[], FIELD_TYPE] | None = None, is_javascript_property: bool | None = None, ) -> FIELD_TYPE: """Create a field for a component. Args: default: The default value for the field. default_factory: The default factory for the field. is_javascript_property: Whether the field is a javascript property. Returns: The field for the component. Raises: ValueError: If both default and default_factory are specified. """ if default is not MISSING and default_factory is not None: raise ValueError("cannot specify both default and default_factory") return ComponentField( # pyright: ignore [reportReturnType] default=default, default_factory=default_factory, is_javascript=is_javascript_property, ) @dataclass_transform(kw_only_default=True) class BaseComponentMeta(ABCMeta): """Meta class for BaseComponent.""" if TYPE_CHECKING: _inherited_fields: Mapping[str, ComponentField] _own_fields: Mapping[str, ComponentField] _fields: Mapping[str, ComponentField] _js_fields: Mapping[str, ComponentField] def __new__(cls, name: str, bases: tuple[type], namespace: dict[str, Any]) -> type: """Create a new class. Args: name: The name of the class. bases: The bases of the class. namespace: The namespace of the class. Returns: The new class. """ # Add the field to the class inherited_fields: dict[str, ComponentField] = {} own_fields: dict[str, ComponentField] = {} resolved_annotations = resolve_annotations( namespace.get("__annotations__", {}), namespace["__module__"] ) for base in bases[::-1]: if hasattr(base, "_inherited_fields"): inherited_fields.update(base._inherited_fields) for base in bases[::-1]: if hasattr(base, "_own_fields"): inherited_fields.update(base._own_fields) for key, value, inherited_field in [ (key, value, inherited_field) for key, value in namespace.items() if key not in resolved_annotations and ((inherited_field := inherited_fields.get(key)) is not None) ]: new_value = ComponentField( default=value, is_javascript=inherited_field.is_javascript, annotated_type=inherited_field.annotated_type, ) own_fields[key] = new_value for key, annotation in resolved_annotations.items(): value = namespace.get(key, MISSING) if types.is_classvar(annotation): # If the annotation is a classvar, skip it. continue if value is MISSING: value = ComponentField( default=None, is_javascript=(key[0] != "_"), annotated_type=annotation, ) elif not isinstance(value, ComponentField): value = ComponentField( default=value, is_javascript=( (key[0] != "_") if (existing_field := inherited_fields.get(key)) is None else existing_field.is_javascript ), annotated_type=annotation, ) else: value = ComponentField( default=value.default, default_factory=value.default_factory, is_javascript=value.is_javascript, annotated_type=annotation, ) own_fields[key] = value namespace["_own_fields"] = own_fields namespace["_inherited_fields"] = inherited_fields namespace["_fields"] = inherited_fields | own_fields namespace["_js_fields"] = { key: value for key, value in own_fields.items() if value.is_javascript is True } return super().__new__(cls, name, bases, namespace) class BaseComponent(metaclass=BaseComponentMeta): """The base class for all Reflex components. This is something that can be rendered as a Component via the Reflex compiler. """ # The children nested within the component. children: list[BaseComponent] = field( default_factory=list, is_javascript_property=False ) # The library that the component is based on. library: str | None = field(default=None, is_javascript_property=False) # List here the non-react dependency needed by `library` lib_dependencies: list[str] = field( default_factory=list, is_javascript_property=False ) # List here the dependencies that need to be transpiled by Next.js transpile_packages: list[str] = field( default_factory=list, is_javascript_property=False ) # The tag to use when rendering the component. tag: str | None = field(default=None, is_javascript_property=False) def __init__( self, **kwargs, ): """Initialize the component. Args: **kwargs: The kwargs to pass to the component. """ for key, value in kwargs.items(): setattr(self, key, value) for name, value in self.get_fields().items(): if name not in kwargs: setattr(self, name, value.default_value()) def set(self, **kwargs): """Set the component props. Args: **kwargs: The kwargs to set. Returns: The component with the updated props. """ for key, value in kwargs.items(): setattr(self, key, value) return self def __eq__(self, value: Any) -> bool: """Check if the component is equal to another value. Args: value: The value to compare to. Returns: Whether the component is equal to the value. """ return type(self) is type(value) and bool( getattr(self, key) == getattr(value, key) for key in self.get_fields() ) @classmethod def get_fields(cls) -> Mapping[str, ComponentField]: """Get the fields of the component. Returns: The fields of the component. """ return cls._fields @classmethod def get_js_fields(cls) -> Mapping[str, ComponentField]: """Get the javascript fields of the component. Returns: The javascript fields of the component. """ return cls._js_fields @abstractmethod def render(self) -> dict: """Render the component. Returns: The dictionary for template of the component. """ @abstractmethod def _get_all_hooks_internal(self) -> dict[str, VarData | None]: """Get the reflex internal hooks for the component and its children. Returns: The code that should appear just before user-defined hooks. """ @abstractmethod def _get_all_hooks(self) -> dict[str, VarData | None]: """Get the React hooks for this component. Returns: The code that should appear just before returning the rendered component. """ @abstractmethod def _get_all_imports(self) -> ParsedImportDict: """Get all the libraries and fields that are used by the component. Returns: The import dict with the required imports. """ @abstractmethod def _get_all_dynamic_imports(self) -> set[str]: """Get dynamic imports for the component. Returns: The dynamic imports. """ @abstractmethod def _get_all_custom_code(self) -> set[str]: """Get custom code for the component. Returns: The custom code. """ @abstractmethod def _get_all_refs(self) -> set[str]: """Get the refs for the children of the component. Returns: The refs for the children. """ class ComponentNamespace(SimpleNamespace): """A namespace to manage components with subcomponents.""" def __hash__(self) -> int: # pyright: ignore [reportIncompatibleVariableOverride] """Get the hash of the namespace. Returns: The hash of the namespace. """ return hash(type(self).__name__) def evaluate_style_namespaces(style: ComponentStyle) -> dict: """Evaluate namespaces in the style. Args: style: The style to evaluate. Returns: The evaluated style. """ return { k.__call__ if isinstance(k, ComponentNamespace) else k: v for k, v in style.items() } # Map from component to styling. ComponentStyle = dict[str | type[BaseComponent] | Callable | ComponentNamespace, Any] ComponentChild = types.PrimitiveType | Var | BaseComponent ComponentChildTypes = (*types.PrimitiveTypes, Var, BaseComponent, type(None)) def _satisfies_type_hint(obj: Any, type_hint: Any) -> bool: return types._isinstance( obj, type_hint, nested=1, treat_var_as_type=True, treat_mutable_obj_as_immutable=( isinstance(obj, Var) and not isinstance(obj, LiteralVar) ), ) def satisfies_type_hint(obj: Any, type_hint: Any) -> bool: """Check if an object satisfies a type hint. Args: obj: The object to check. type_hint: The type hint to check against. Returns: Whether the object satisfies the type hint. """ if _satisfies_type_hint(obj, type_hint): return True if _satisfies_type_hint(obj, type_hint | None): obj = ( obj if not isinstance(obj, Var) else (obj._var_value if isinstance(obj, LiteralVar) else obj) ) console.deprecate( "implicit-none-for-component-fields", reason="Passing Vars with possible None values to component fields not explicitly marked as Optional is deprecated. " + f"Passed {obj!s} of type {escape(str(type(obj) if not isinstance(obj, Var) else obj._var_type))} to {escape(str(type_hint))}.", deprecation_version="0.7.2", removal_version="0.8.0", ) return True return False def _components_from( component_or_var: BaseComponent | Var, ) -> tuple[BaseComponent, ...]: """Get the components from a component or Var. Args: component_or_var: The component or Var to get the components from. Returns: The components. """ if isinstance(component_or_var, Var): var_data = component_or_var._get_all_var_data() return var_data.components if var_data else () if isinstance(component_or_var, BaseComponent): return (component_or_var,) return () DEFAULT_TRIGGERS: dict[str, types.ArgsSpec | Sequence[types.ArgsSpec]] = { EventTriggers.ON_FOCUS: no_args_event_spec, EventTriggers.ON_BLUR: no_args_event_spec, EventTriggers.ON_CLICK: no_args_event_spec, EventTriggers.ON_CONTEXT_MENU: no_args_event_spec, EventTriggers.ON_DOUBLE_CLICK: no_args_event_spec, EventTriggers.ON_MOUSE_DOWN: no_args_event_spec, EventTriggers.ON_MOUSE_ENTER: no_args_event_spec, EventTriggers.ON_MOUSE_LEAVE: no_args_event_spec, EventTriggers.ON_MOUSE_MOVE: no_args_event_spec, EventTriggers.ON_MOUSE_OUT: no_args_event_spec, EventTriggers.ON_MOUSE_OVER: no_args_event_spec, EventTriggers.ON_MOUSE_UP: no_args_event_spec, EventTriggers.ON_SCROLL: no_args_event_spec, EventTriggers.ON_MOUNT: no_args_event_spec, EventTriggers.ON_UNMOUNT: no_args_event_spec, } T = TypeVar("T", bound="Component") class Component(BaseComponent, ABC): """A component with style, event trigger and other props.""" # The style of the component. style: Style = field(default_factory=Style, is_javascript_property=False) # A mapping from event triggers to event chains. event_triggers: dict[str, EventChain | Var] = field( default_factory=dict, is_javascript_property=False ) # The alias for the tag. alias: str | None = field(default=None, is_javascript_property=False) # Whether the component is a global scope tag. True for tags like `html`, `head`, `body`. _is_tag_in_global_scope: ClassVar[bool] = False # Whether the import is default or named. is_default: bool | None = field(default=False, is_javascript_property=False) # A unique key for the component. key: Any = field(default=None, is_javascript_property=False) # The id for the component. id: Any = field(default=None, is_javascript_property=False) # The Var to pass as the ref to the component. ref: Var | None = field(default=None, is_javascript_property=False) # The class name for the component. class_name: Any = field(default=None, is_javascript_property=False) # Special component props. special_props: list[Var] = field(default_factory=list, is_javascript_property=False) # Whether the component should take the focus once the page is loaded autofocus: bool = field(default=False, is_javascript_property=False) # components that cannot be children _invalid_children: ClassVar[list[str]] = [] # only components that are allowed as children _valid_children: ClassVar[list[str]] = [] # only components that are allowed as parent _valid_parents: ClassVar[list[str]] = [] # props to change the name of _rename_props: ClassVar[dict[str, str]] = {} # custom attribute custom_attrs: dict[str, Var | Any] = field( default_factory=dict, is_javascript_property=False ) # When to memoize this component and its children. _memoization_mode: MemoizationMode = field( default_factory=MemoizationMode, is_javascript_property=False ) # State class associated with this component instance State: type[reflex.state.State] | None = field( default=None, is_javascript_property=False ) def add_imports(self) -> ImportDict | list[ImportDict]: """Add imports for the component. This method should be implemented by subclasses to add new imports for the component. Implementations do NOT need to call super(). The result of calling add_imports in each parent class will be merged internally. Returns: The additional imports for this component subclass. The format of the return value is a dictionary where the keys are the library names (with optional npm-style version specifications) mapping to a single name to be imported, or a list names to be imported. For advanced use cases, the values can be ImportVar instances (for example, to provide an alias or mark that an import is the default export from the given library). ```python return { "react": "useEffect", "react-draggable": ["DraggableCore", rx.ImportVar(tag="Draggable", is_default=True)], } ``` """ return {} def add_hooks(self) -> list[str | Var]: """Add hooks inside the component function. Hooks are pieces of literal Javascript code that is inserted inside the React component function. Each logical hook should be a separate string in the list. Common strings will be deduplicated and inserted into the component function only once, so define const variables and other identical code in their own strings to avoid defining the same const or hook multiple times. If a hook depends on specific data from the component instance, be sure to use unique values inside the string to _avoid_ deduplication. Implementations do NOT need to call super(). The result of calling add_hooks in each parent class will be merged and deduplicated internally. Returns: The additional hooks for this component subclass. ```python return [ "const [count, setCount] = useState(0);", "useEffect(() => { setCount((prev) => prev + 1); console.log(`mounted ${count} times`); }, []);", ] ``` """ return [] def add_custom_code(self) -> list[str]: """Add custom Javascript code into the page that contains this component. Custom code is inserted at module level, after any imports. Each string of custom code is deduplicated per-page, so take care to avoid defining the same const or function differently from different component instances. Custom code is useful for defining global functions or constants which can then be referenced inside hooks or used by component vars. Implementations do NOT need to call super(). The result of calling add_custom_code in each parent class will be merged and deduplicated internally. Returns: The additional custom code for this component subclass. ```python return [ "const translatePoints = (event) => { return { x: event.clientX, y: event.clientY }; };", ] ``` """ return [] @classmethod def __init_subclass__(cls, **kwargs): """Set default properties. Args: **kwargs: The kwargs to pass to the superclass. """ super().__init_subclass__(**kwargs) # Ensure renamed props from parent classes are applied to the subclass. if cls._rename_props: inherited_rename_props = {} for parent in reversed(cls.mro()): if issubclass(parent, Component) and parent._rename_props: inherited_rename_props.update(parent._rename_props) cls._rename_props = inherited_rename_props def __init__(self, **kwargs): """Initialize the custom component. Args: **kwargs: The kwargs to pass to the component. """ super().__init__( children=kwargs.get("children", []), ) console.deprecate( "component-direct-instantiation", reason="Use the `create` method instead.", deprecation_version="0.7.2", removal_version="0.8.0", ) self._post_init(**kwargs) def _post_init(self, *args, **kwargs): """Initialize the component. Args: *args: Args to initialize the component. **kwargs: Kwargs to initialize the component. Raises: TypeError: If an invalid prop is passed. ValueError: If an event trigger passed is not valid. """ # Set the id and children initially. children = kwargs.get("children", []) self._validate_component_children(children) # Get the component fields, triggers, and props. fields = self.get_fields() component_specific_triggers = self.get_event_triggers() props = self.get_props() # Add any events triggers. if "event_triggers" not in kwargs: kwargs["event_triggers"] = {} kwargs["event_triggers"] = kwargs["event_triggers"].copy() # Iterate through the kwargs and set the props. for key, value in kwargs.items(): if ( key.startswith("on_") and key not in component_specific_triggers and key not in props ): raise ValueError( f"The {(comp_name := type(self).__name__)} does not take in an `{key}` event trigger. If {comp_name}" f" is a third party component make sure to add `{key}` to the component's event triggers. " f"visit https://reflex.dev/docs/wrapping-react/guide/#event-triggers for more info." ) if key in component_specific_triggers: # Event triggers are bound to event chains. is_var = False elif key in props: # Set the field type. is_var = ( field.type_origin is Var if (field := fields.get(key)) else False ) else: continue def determine_key(value: Any): # Try to create a var from the value key = value if isinstance(value, Var) else LiteralVar.create(value) # Check that the var type is not None. if key is None: raise TypeError return key # Check whether the key is a component prop. if is_var: try: kwargs[key] = determine_key(value) expected_type = types.get_args( types.get_field_type(type(self), key) )[0] # validate literal fields. types.validate_literal( key, value, expected_type, type(self).__name__ ) # Get the passed type and the var type. passed_type = kwargs[key]._var_type expected_type = ( type(expected_type.__args__[0]) if types.is_literal(expected_type) else expected_type ) except TypeError: # If it is not a valid var, check the base types. passed_type = type(value) expected_type = types.get_field_type(type(self), key) if not satisfies_type_hint(value, expected_type): value_name = value._js_expr if isinstance(value, Var) else value additional_info = ( " You can call `.bool()` on the value to convert it to a boolean." if expected_type is bool and isinstance(value, Var) else "" ) raise TypeError( f"Invalid var passed for prop {type(self).__name__}.{key}, expected type {expected_type}, got value {value_name} of type {passed_type}." + additional_info ) # Check if the key is an event trigger. if key in component_specific_triggers: kwargs["event_triggers"][key] = EventChain.create( value=value, args_spec=component_specific_triggers[key], key=key, ) # Remove any keys that were added as events. for key in kwargs["event_triggers"]: kwargs.pop(key, None) # Place data_ and aria_ attributes into custom_attrs special_attributes = tuple( key for key in kwargs if key not in fields and SpecialAttributes.is_special(key) ) if special_attributes: custom_attrs = kwargs.setdefault("custom_attrs", {}) for key in special_attributes: custom_attrs[format.to_kebab_case(key)] = kwargs.pop(key) # Add style props to the component. style = kwargs.get("style", {}) if isinstance(style, Sequence): if any(not isinstance(s, Mapping) for s in style): raise TypeError("Style must be a dictionary or a list of dictionaries.") # Merge styles, the later ones overriding keys in the earlier ones. style = { k: v for style_dict in style for k, v in cast(Mapping, style_dict).items() } if isinstance(style, (Breakpoints, Var)): style = { # Assign the Breakpoints to the self-referential selector to avoid squashing down to a regular dict. "&": style, } fields_style = self.get_fields()["style"] kwargs["style"] = Style( { **fields_style.default_value(), **style, **{attr: value for attr, value in kwargs.items() if attr not in fields}, } ) # Convert class_name to str if it's list class_name = kwargs.get("class_name", "") if isinstance(class_name, (list, tuple)): has_var = False for c in class_name: if isinstance(c, str): continue if isinstance(c, Var): if not isinstance(c, StringVar) and not issubclass( c._var_type, str ): raise TypeError( f"Invalid class_name passed for prop {type(self).__name__}.class_name, expected type str, got value {c._js_expr} of type {c._var_type}." ) has_var = True else: raise TypeError( f"Invalid class_name passed for prop {type(self).__name__}.class_name, expected type str, got value {c} of type {type(c)}." ) if has_var: kwargs["class_name"] = LiteralArrayVar.create( class_name, _var_type=list[str] ).join(" ") else: kwargs["class_name"] = " ".join(class_name) elif ( isinstance(class_name, Var) and not isinstance(class_name, StringVar) and not issubclass(class_name._var_type, str) ): raise TypeError( f"Invalid class_name passed for prop {type(self).__name__}.class_name, expected type str, got value {class_name._js_expr} of type {class_name._var_type}." ) # Construct the component. for key, value in kwargs.items(): setattr(self, key, value) def get_event_triggers( self, ) -> dict[str, types.ArgsSpec | Sequence[types.ArgsSpec]]: """Get the event triggers for the component. Returns: The event triggers. """ # Look for component specific triggers, # e.g. variable declared as EventHandler types. return DEFAULT_TRIGGERS | { name: ( metadata[0] if ( (metadata := getattr(field.annotated_type, "__metadata__", None)) is not None ) else no_args_event_spec ) for name, field in self.get_fields().items() if field.type_origin is EventHandler } def __repr__(self) -> str: """Represent the component in React. Returns: The code to render the component. """ return format.json_dumps(self.render()) def __str__(self) -> str: """Represent the component in React. Returns: The code to render the component. """ from reflex.compiler.compiler import _compile_component return _compile_component(self) def _exclude_props(self) -> list[str]: """Props to exclude when adding the component props to the Tag. Returns: A list of component props to exclude. """ return [] def _render(self, props: dict[str, Any] | None = None) -> Tag: """Define how to render the component in React. Args: props: The props to render (if None, then use get_props). Returns: The tag to render. """ # Create the base tag. name = (self.tag if not self.alias else self.alias) or "" if self._is_tag_in_global_scope and self.library is None: name = '"' + name + '"' # Create the base tag. tag = Tag( name=name, special_props=self.special_props, ) if props is None: # Add component props to the tag. props = { attr.removesuffix("_"): getattr(self, attr) for attr in self.get_props() } # Add ref to element if `ref` is None and `id` is not None. if self.ref is not None: props["ref"] = self.ref elif (ref := self.get_ref()) is not None: props["ref"] = Var(_js_expr=ref) else: props = props.copy() props.update( **{ trigger: handler for trigger, handler in self.event_triggers.items() if trigger not in {EventTriggers.ON_MOUNT, EventTriggers.ON_UNMOUNT} }, key=self.key, id=self.id, class_name=self.class_name, ) props.update(self._get_style()) props.update(self.custom_attrs) # remove excluded props from prop dict before adding to tag. for prop_to_exclude in self._exclude_props(): props.pop(prop_to_exclude, None) return tag.add_props(**props) @classmethod @functools.cache def get_props(cls) -> set[str]: """Get the unique fields for the component. Returns: The unique fields. """ return set(cls.get_fields()) - set(Component.get_fields()) @classmethod @functools.cache def get_initial_props(cls) -> set[str]: """Get the initial props to set for the component. Returns: The initial props to set. """ return set() @classmethod def _are_fields_known(cls) -> bool: """Check if all fields are known at compile time. True for most components. Returns: Whether all fields are known at compile time. """ return True @classmethod @functools.cache def _get_component_prop_names(cls) -> set[str]: """Get the names of the component props. NOTE: This assumes all fields are known. Returns: The names of the component props. """ return { name for name in cls.get_fields() if name in cls.get_props() and types._issubclass( types.value_inside_optional(types.get_field_type(cls, name)), Component ) } def _get_components_in_props(self) -> Sequence[BaseComponent]: """Get the components in the props. Returns: The components in the props """ if self._are_fields_known(): return [ component for name in self._get_component_prop_names() for component in _components_from(getattr(self, name)) ] return [ component for prop in self.get_props() if (value := getattr(self, prop)) is not None and isinstance(value, (BaseComponent, Var)) for component in _components_from(value) ] @classmethod def create(cls: type[T], *children, **props) -> T: """Create the component. Args: *children: The children of the component. **props: The props of the component. Returns: The component. """ # Import here to avoid circular imports. from reflex.components.base.bare import Bare from reflex.components.base.fragment import Fragment from reflex.utils.exceptions import ChildrenTypeError # Filter out None props props = {key: value for key, value in props.items() if value is not None} def validate_children(children: tuple | list): for child in children: if isinstance(child, (tuple, list)): validate_children(child) # Make sure the child is a valid type. if isinstance(child, dict) or not isinstance( child, ComponentChildTypes ): raise ChildrenTypeError(component=cls.__name__, child=child) # Validate all the children. validate_children(children) children_normalized = [ ( child if isinstance(child, Component) else ( Fragment.create(*child) if isinstance(child, tuple) else Bare.create(contents=LiteralVar.create(child)) ) ) for child in children ] return cls._create(children_normalized, **props) @classmethod def _create(cls: type[T], children: Sequence[BaseComponent], **props: Any) -> T: """Create the component. Args: children: The children of the component. **props: The props of the component. Returns: The component. """ comp = cls.__new__(cls) super(Component, comp).__init__(id=props.get("id"), children=list(children)) comp._post_init(children=list(children), **props) return comp @classmethod def _unsafe_create( cls: type[T], children: Sequence[BaseComponent], **props: Any ) -> T: """Create the component without running post_init. Args: children: The children of the component. **props: The props of the component. Returns: The component. """ comp = cls.__new__(cls) super(Component, comp).__init__(id=props.get("id"), children=list(children)) for prop, value in props.items(): setattr(comp, prop, value) return comp def add_style(self) -> dict[str, Any] | None: """Add style to the component. Downstream components can override this method to return a style dict that will be applied to the component. Returns: The style to add. """ return None def _add_style(self) -> Style: """Call add_style for all bases in the MRO. Downstream components should NOT override. Use add_style instead. Returns: The style to add. """ styles = [] # Walk the MRO to call all `add_style` methods. for base in self._iter_parent_classes_with_method("add_style"): s = base.add_style(self) if s is not None: styles.append(s) _style = Style() for s in reversed(styles): _style.update(s) return _style def _get_component_style(self, styles: ComponentStyle | Style) -> Style | None: """Get the style to the component from `App.style`. Args: styles: The style to apply. Returns: The style of the component. """ component_style = None if (style := styles.get(type(self))) is not None: # pyright: ignore [reportArgumentType] component_style = Style(style) if (style := styles.get(self.create)) is not None: # pyright: ignore [reportArgumentType] component_style = Style(style) return component_style def _add_style_recursive( self, style: ComponentStyle | Style, theme: Component | None = None ) -> Component: """Add additional style to the component and its children. Apply order is as follows (with the latest overriding the earliest): 1. Default style from `_add_style`/`add_style`. 2. User-defined style from `App.style`. 3. User-defined style from `Component.style`. 4. style dict and css props passed to the component instance. Args: style: A dict from component to styling. theme: The theme to apply. (for retro-compatibility with deprecated _apply_theme API) Raises: UserWarning: If `_add_style` has been overridden. Returns: The component with the additional style. """ # 1. Default style from `_add_style`/`add_style`. if type(self)._add_style != Component._add_style: raise UserWarning( "Do not override _add_style directly. Use add_style instead." ) new_style = self._add_style() style_vars = [new_style._var_data] # 2. User-defined style from `App.style`. component_style = self._get_component_style(style) if component_style: new_style.update(component_style) style_vars.append(component_style._var_data) # 4. style dict and css props passed to the component instance. new_style.update(self.style) style_vars.append(self.style._var_data) new_style._var_data = VarData.merge(*style_vars) # Assign the new style self.style = new_style # Recursively add style to the children. for child in self.children: # Skip BaseComponent and StatefulComponent children. if not isinstance(child, Component): continue child._add_style_recursive(style, theme) return self def _get_style(self) -> dict: """Get the style for the component. Returns: The dictionary of the component style as value and the style notation as key. """ if isinstance(self.style, Var): return {"css": self.style} emotion_style = format_as_emotion(self.style) return ( {"css": LiteralVar.create(emotion_style)} if emotion_style is not None else {} ) def render(self) -> dict: """Render the component. Returns: The dictionary for template of component. """ tag = self._render() rendered_dict = dict( tag.set( children=[child.render() for child in self.children], contents=str(tag.contents), props=tag.format_props(), ), autofocus=self.autofocus, ) self._replace_prop_names(rendered_dict) return rendered_dict def _replace_prop_names(self, rendered_dict: dict) -> None: """Replace the prop names in the render dictionary. Args: rendered_dict: The render dictionary with all the component props and event handlers. """ # fast path if not self._rename_props: return for ix, prop in enumerate(rendered_dict["props"]): for old_prop, new_prop in self._rename_props.items(): if prop.startswith(old_prop): rendered_dict["props"][ix] = prop.replace(old_prop, new_prop, 1) def _validate_component_children(self, children: list[Component]): """Validate the children components. Args: children: The children of the component. """ from reflex.components.base.fragment import Fragment from reflex.components.core.cond import Cond from reflex.components.core.foreach import Foreach from reflex.components.core.match import Match no_valid_parents_defined = all(child._valid_parents == [] for child in children) if ( not self._invalid_children and not self._valid_children and no_valid_parents_defined ): return comp_name = type(self).__name__ allowed_components = [ comp.__name__ for comp in (Fragment, Foreach, Cond, Match) ] def validate_child(child: Any): child_name = type(child).__name__ # Iterate through the immediate children of fragment if isinstance(child, Fragment): for c in child.children: validate_child(c) if isinstance(child, Cond): validate_child(child.children[0]) validate_child(child.children[1]) if isinstance(child, Match): for cases in child.match_cases: validate_child(cases[-1]) validate_child(child.default) if self._invalid_children and child_name in self._invalid_children: raise ValueError( f"The component `{comp_name}` cannot have `{child_name}` as a child component" ) if self._valid_children and child_name not in [ *self._valid_children, *allowed_components, ]: valid_child_list = ", ".join( [f"`{v_child}`" for v_child in self._valid_children] ) raise ValueError( f"The component `{comp_name}` only allows the components: {valid_child_list} as children. Got `{child_name}` instead." ) if child._valid_parents and all( clz_name not in [*child._valid_parents, *allowed_components] for clz_name in self._iter_parent_classes_names() ): valid_parent_list = ", ".join( [f"`{v_parent}`" for v_parent in child._valid_parents] ) raise ValueError( f"The component `{child_name}` can only be a child of the components: {valid_parent_list}. Got `{comp_name}` instead." ) for child in children: validate_child(child) @staticmethod def _get_vars_from_event_triggers( event_triggers: dict[str, EventChain | Var], ) -> Iterator[tuple[str, list[Var]]]: """Get the Vars associated with each event trigger. Args: event_triggers: The event triggers from the component instance. Yields: tuple of (event_name, event_vars) """ for event_trigger, event in event_triggers.items(): if isinstance(event, Var): yield event_trigger, [event] elif isinstance(event, EventChain): event_args = [] for spec in event.events: if isinstance(spec, EventSpec): for args in spec.args: event_args.extend(args) else: event_args.append(spec) yield event_trigger, event_args def _get_vars( self, include_children: bool = False, ignore_ids: set[int] | None = None ) -> Iterator[Var]: """Walk all Vars used in this component. Args: include_children: Whether to include Vars from children. ignore_ids: The ids to ignore. Yields: Each var referenced by the component (props, styles, event handlers). """ ignore_ids = ignore_ids or set() vars: list[Var] | None = getattr(self, "__vars", None) if vars is not None: yield from vars vars = self.__vars = [] # Get Vars associated with event trigger arguments. for _, event_vars in self._get_vars_from_event_triggers(self.event_triggers): vars.extend(event_vars) # Get Vars associated with component props. for prop in self.get_props(): prop_var = getattr(self, prop) if isinstance(prop_var, Var): vars.append(prop_var) # Style keeps track of its own VarData instance, so embed in a temp Var that is yielded. if (isinstance(self.style, dict) and self.style) or isinstance(self.style, Var): vars.append( Var( _js_expr="style", _var_type=str, _var_data=VarData.merge(self.style._var_data), ) ) # Special props are always Var instances. vars.extend(self.special_props) # Get Vars associated with common Component props. for comp_prop in ( self.class_name, self.id, self.key, self.autofocus, *self.custom_attrs.values(), ): if isinstance(comp_prop, Var): vars.append(comp_prop) elif isinstance(comp_prop, str): # Collapse VarData encoded in f-strings. var = LiteralStringVar.create(comp_prop) if var._get_all_var_data() is not None: vars.append(var) # Get Vars associated with children. if include_children: for child in self.children: if not isinstance(child, Component) or id(child) in ignore_ids: continue ignore_ids.add(id(child)) child_vars = child._get_vars( include_children=include_children, ignore_ids=ignore_ids ) vars.extend(child_vars) yield from vars def _event_trigger_values_use_state(self) -> bool: """Check if the values of a component's event trigger use state. Returns: True if any of the component's event trigger values uses State. """ for trigger in self.event_triggers.values(): if isinstance(trigger, EventChain): for event in trigger.events: if isinstance(event, EventCallback): continue if isinstance(event, EventSpec): if ( event.handler.state_full_name and event.handler.state_full_name != FRONTEND_EVENT_STATE ): return True else: if event._var_state: return True elif isinstance(trigger, Var) and trigger._var_state: return True return False def _has_stateful_event_triggers(self): """Check if component or children have any event triggers that use state. Returns: True if the component or children have any event triggers that uses state. """ if self.event_triggers and self._event_trigger_values_use_state(): return True else: for child in self.children: if ( isinstance(child, Component) and child._has_stateful_event_triggers() ): return True return False @classmethod def _iter_parent_classes_names(cls) -> Iterator[str]: for clz in cls.mro(): if clz is Component: break yield clz.__name__ @classmethod def _iter_parent_classes_with_method(cls, method: str) -> Iterator[type[Component]]: """Iterate through parent classes that define a given method. Used for handling the `add_*` API functions that internally simulate a super() call chain. Args: method: The method to look for. Yields: The parent classes that define the method (differently than the base). """ seen_methods = ( {getattr(Component, method)} if hasattr(Component, method) else set() ) for clz in cls.mro(): if clz is Component: break if not issubclass(clz, Component): continue method_func = getattr(clz, method, None) if not callable(method_func) or method_func in seen_methods: continue seen_methods.add(method_func) yield clz def _get_custom_code(self) -> str | None: """Get custom code for the component. Returns: The custom code. """ return None def _get_all_custom_code(self) -> set[str]: """Get custom code for the component and its children. Returns: The custom code. """ # Store the code in a set to avoid duplicates. code = set() # Add the custom code for this component. custom_code = self._get_custom_code() if custom_code is not None: code.add(custom_code) for component in self._get_components_in_props(): code |= component._get_all_custom_code() # Add the custom code from add_custom_code method. for clz in self._iter_parent_classes_with_method("add_custom_code"): for item in clz.add_custom_code(self): code.add(item) # Add the custom code for the children. for child in self.children: code |= child._get_all_custom_code() # Return the code. return code def _get_dynamic_imports(self) -> str | None: """Get dynamic import for the component. Returns: The dynamic import. """ return None def _get_all_dynamic_imports(self) -> set[str]: """Get dynamic imports for the component and its children. Returns: The dynamic imports. """ # Store the import in a set to avoid duplicates. dynamic_imports: set[str] = set() # Get dynamic import for this component. dynamic_import = self._get_dynamic_imports() if dynamic_import: dynamic_imports.add(dynamic_import) # Get the dynamic imports from children for child in self.children: dynamic_imports |= child._get_all_dynamic_imports() for component in self._get_components_in_props(): dynamic_imports |= component._get_all_dynamic_imports() # Return the dynamic imports return dynamic_imports def _should_transpile(self, dep: str | None) -> bool: """Check if a dependency should be transpiled. Args: dep: The dependency to check. Returns: True if the dependency should be transpiled. """ return bool(self.transpile_packages) and ( dep in self.transpile_packages or format.format_library_name(dep or "") in self.transpile_packages ) def _get_dependencies_imports(self) -> ParsedImportDict: """Get the imports from lib_dependencies for installing. Returns: The dependencies imports of the component. """ return { dep: [ ImportVar( tag=None, render=False, transpile=self._should_transpile(dep), ) ] for dep in self.lib_dependencies } def _get_hooks_imports(self) -> ParsedImportDict: """Get the imports required by certain hooks. Returns: The imports required for all selected hooks. """ _imports = {} if self._get_ref_hook() is not None: # Handle hooks needed for attaching react refs to DOM nodes. _imports.setdefault("react", set()).add(ImportVar(tag="useRef")) _imports.setdefault(f"$/{Dirs.STATE_PATH}", set()).add( ImportVar(tag="refs") ) if self._get_mount_lifecycle_hook(): # Handle hooks for `on_mount` / `on_unmount`. _imports.setdefault("react", set()).add(ImportVar(tag="useEffect")) if self._get_special_hooks(): # Handle additional internal hooks (autofocus, etc). _imports.setdefault("react", set()).update( { ImportVar(tag="useRef"), ImportVar(tag="useEffect"), }, ) other_imports = [] user_hooks = self._get_hooks() user_hooks_data = ( VarData.merge(user_hooks._get_all_var_data()) if user_hooks is not None and isinstance(user_hooks, Var) else None ) if user_hooks_data is not None: other_imports.append(user_hooks_data.imports) other_imports.extend( hook_vardata.imports for hook_vardata in self._get_added_hooks().values() if hook_vardata is not None ) return imports.merge_imports(_imports, *other_imports) def _get_imports(self) -> ParsedImportDict: """Get all the libraries and fields that are used by the component. Returns: The imports needed by the component. """ _imports = {} # Import this component's tag from the main library. if self.library is not None and self.tag is not None: _imports[self.library] = {self.import_var} # Get static imports required for event processing. event_imports = Imports.EVENTS if self.event_triggers else {} # Collect imports from Vars used directly by this component. var_imports = [ var_data.imports for var in self._get_vars() if (var_data := var._get_all_var_data()) is not None ] added_import_dicts: list[ParsedImportDict] = [] for clz in self._iter_parent_classes_with_method("add_imports"): list_of_import_dict = clz.add_imports(self) if not isinstance(list_of_import_dict, list): list_of_import_dict = [list_of_import_dict] added_import_dicts.extend( [parse_imports(import_dict) for import_dict in list_of_import_dict] ) return imports.merge_imports( self._get_dependencies_imports(), self._get_hooks_imports(), _imports, event_imports, *var_imports, *added_import_dicts, ) def _get_all_imports(self, collapse: bool = False) -> ParsedImportDict: """Get all the libraries and fields that are used by the component and its children. Args: collapse: Whether to collapse the imports by removing duplicates. Returns: The import dict with the required imports. """ _imports = imports.merge_imports( self._get_imports(), *[child._get_all_imports() for child in self.children] ) return imports.collapse_imports(_imports) if collapse else _imports def _get_mount_lifecycle_hook(self) -> str | None: """Generate the component lifecycle hook. Returns: The useEffect hook for managing `on_mount` and `on_unmount` events. """ # pop on_mount and on_unmount from event_triggers since these are handled by # hooks, not as actually props in the component on_mount = self.event_triggers.get(EventTriggers.ON_MOUNT, None) on_unmount = self.event_triggers.get(EventTriggers.ON_UNMOUNT, None) if on_mount is not None: on_mount = str(LiteralVar.create(on_mount)) + "()" if on_unmount is not None: on_unmount = str(LiteralVar.create(on_unmount)) + "()" if on_mount is not None or on_unmount is not None: return f""" useEffect(() => {{ {on_mount or ""} return () => {{ {on_unmount or ""} }} }}, []);""" def _get_ref_hook(self) -> Var | None: """Generate the ref hook for the component. Returns: The useRef hook for managing refs. """ ref = self.get_ref() if ref is not None: return Var( f"const {ref} = useRef(null); {Var(_js_expr=ref)._as_ref()!s} = {ref};", _var_data=VarData(position=Hooks.HookPosition.INTERNAL), ) def _get_vars_hooks(self) -> dict[str, VarData | None]: """Get the hooks required by vars referenced in this component. Returns: The hooks for the vars. """ vars_hooks = {} for var in self._get_vars(): var_data = var._get_all_var_data() if var_data is not None: vars_hooks.update( var_data.hooks if isinstance(var_data.hooks, dict) else { k: VarData(position=Hooks.HookPosition.INTERNAL) for k in var_data.hooks } ) for component in var_data.components: vars_hooks.update(component._get_all_hooks()) return vars_hooks def _get_events_hooks(self) -> dict[str, VarData | None]: """Get the hooks required by events referenced in this component. Returns: The hooks for the events. """ return ( {Hooks.EVENTS: VarData(position=Hooks.HookPosition.INTERNAL)} if self.event_triggers else {} ) def _get_special_hooks(self) -> dict[str, VarData | None]: """Get the hooks required by special actions referenced in this component. Returns: The hooks for special actions. """ return ( {Hooks.AUTOFOCUS: VarData(position=Hooks.HookPosition.INTERNAL)} if self.autofocus else {} ) def _get_hooks_internal(self) -> dict[str, VarData | None]: """Get the React hooks for this component managed by the framework. Downstream components should NOT override this method to avoid breaking framework functionality. Returns: The internally managed hooks. """ return { **{ str(hook): VarData(position=Hooks.HookPosition.INTERNAL) for hook in [self._get_ref_hook(), self._get_mount_lifecycle_hook()] if hook is not None }, **self._get_vars_hooks(), **self._get_events_hooks(), **self._get_special_hooks(), } def _get_added_hooks(self) -> dict[str, VarData | None]: """Get the hooks added via `add_hooks` method. Returns: The deduplicated hooks and imports added by the component and parent components. """ code = {} def extract_var_hooks(hook: Var): var_data = VarData.merge(hook._get_all_var_data()) if var_data is not None: for sub_hook in var_data.hooks: code[sub_hook] = None if str(hook) in code: code[str(hook)] = VarData.merge(var_data, code[str(hook)]) else: code[str(hook)] = var_data # Add the hook code from add_hooks for each parent class (this is reversed to preserve # the order of the hooks in the final output) for clz in reversed(tuple(self._iter_parent_classes_with_method("add_hooks"))): for hook in clz.add_hooks(self): if isinstance(hook, Var): extract_var_hooks(hook) else: code[hook] = None return code def _get_hooks(self) -> str | None: """Get the React hooks for this component. Downstream components should override this method to add their own hooks. Returns: The hooks for just this component. """ return def _get_all_hooks_internal(self) -> dict[str, VarData | None]: """Get the reflex internal hooks for the component and its children. Returns: The code that should appear just before user-defined hooks. """ # Store the code in a set to avoid duplicates. code = self._get_hooks_internal() # Add the hook code for the children. for child in self.children: code = {**code, **child._get_all_hooks_internal()} return code def _get_all_hooks(self) -> dict[str, VarData | None]: """Get the React hooks for this component and its children. Returns: The code that should appear just before returning the rendered component. """ code = {} # Add the internal hooks for this component. code.update(self._get_hooks_internal()) # Add the hook code for this component. hooks = self._get_hooks() if hooks is not None: code[hooks] = None code.update(self._get_added_hooks()) # Add the hook code for the children. for child in self.children: code = {**code, **child._get_all_hooks()} return code def get_ref(self) -> str | None: """Get the name of the ref for the component. Returns: The ref name. """ # do not create a ref if the id is dynamic or unspecified if self.id is None or isinstance(self.id, Var): return None return format.format_ref(self.id) def _get_all_refs(self) -> set[str]: """Get the refs for the children of the component. Returns: The refs for the children. """ refs = set() ref = self.get_ref() if ref is not None: refs.add(ref) for child in self.children: refs |= child._get_all_refs() for component in self._get_components_in_props(): refs |= component._get_all_refs() return refs @property def import_var(self): """The tag to import. Returns: An import var. """ # If the tag is dot-qualified, only import the left-most name. tag = self.tag.partition(".")[0] if self.tag else None alias = self.alias.partition(".")[0] if self.alias else None return ImportVar( tag=tag, is_default=self.is_default, alias=alias, transpile=self._should_transpile(self.library), ) @staticmethod def _get_app_wrap_components() -> dict[tuple[int, str], Component]: """Get the app wrap components for the component. Returns: The app wrap components. """ return {} def _get_all_app_wrap_components(self) -> dict[tuple[int, str], Component]: """Get the app wrap components for the component and its children. Returns: The app wrap components. """ # Store the components in a set to avoid duplicates. components = self._get_app_wrap_components() for component in tuple(components.values()): components.update(component._get_all_app_wrap_components()) # Add the app wrap components for the children. for child in self.children: # Skip BaseComponent and StatefulComponent children. if not isinstance(child, Component): continue components.update(child._get_all_app_wrap_components()) # Return the components. return components class CustomComponent(Component): """A custom user-defined component.""" # Use the components library. library = f"$/{Dirs.COMPONENTS_PATH}" # The function that creates the component. component_fn: Callable[..., Component] = field(default=Component.create) # The props of the component. props: dict[str, Any] = field(default_factory=dict) def _post_init(self, **kwargs): """Initialize the custom component. Args: **kwargs: The kwargs to pass to the component. """ component_fn = kwargs.get("component_fn") # Set the props. props_types = typing.get_type_hints(component_fn) if component_fn else {} props = {key: value for key, value in kwargs.items() if key in props_types} kwargs = {key: value for key, value in kwargs.items() if key not in props_types} event_types = { key for key in props if ( (get_origin((annotation := props_types.get(key))) or annotation) == EventHandler ) } def get_args_spec(key: str) -> types.ArgsSpec | Sequence[types.ArgsSpec]: type_ = props_types[key] return ( args[0] if (args := get_args(type_)) else ( annotation_args[1] if get_origin( annotation := inspect.getfullargspec(component_fn).annotations[ key ] ) is typing.Annotated and (annotation_args := get_args(annotation)) else no_args_event_spec ) ) super()._post_init( event_triggers={ key: EventChain.create( value=props[key], args_spec=get_args_spec(key), key=key, ) for key in event_types }, **kwargs, ) to_camel_cased_props = { format.to_camel_case(key) for key in props if key not in event_types } self.get_props = lambda: to_camel_cased_props # pyright: ignore [reportIncompatibleVariableOverride] # Unset the style. self.style = Style() # Set the tag to the name of the function. self.tag = format.to_title_case(self.component_fn.__name__) for key, value in props.items(): # Skip kwargs that are not props. if key not in props_types: continue camel_cased_key = format.to_camel_case(key) # Get the type based on the annotation. type_ = props_types[key] # Handle event chains. if type_ is EventHandler: inspect.getfullargspec(component_fn).annotations[key] self.props[camel_cased_key] = EventChain.create( value=value, args_spec=get_args_spec(key), key=key ) continue value = LiteralVar.create(value) self.props[camel_cased_key] = value setattr(self, camel_cased_key, value) @classmethod def _are_fields_known(cls) -> bool: """Check if the fields are known. Returns: Whether the fields are known. """ return False def __eq__(self, other: Any) -> bool: """Check if the component is equal to another. Args: other: The other component. Returns: Whether the component is equal to the other. """ return isinstance(other, CustomComponent) and self.tag == other.tag def __hash__(self) -> int: """Get the hash of the component. Returns: The hash of the component. """ return hash(self.tag) @classmethod def get_props(cls) -> set[str]: """Get the props for the component. Returns: The set of component props. """ return set() @staticmethod def _get_event_spec_from_args_spec(name: str, event: EventChain) -> Callable: """Get the event spec from the args spec. Args: name: The name of the event event: The args spec. Returns: The event spec. """ def fn(*args): return run_script(Var(name).to(FunctionVar).call(*args)) if event.args_spec: arg_spec = ( event.args_spec if not isinstance(event.args_spec, Sequence) else event.args_spec[0] ) names = inspect.getfullargspec(arg_spec).args fn.__signature__ = inspect.Signature( # pyright: ignore[reportFunctionMemberAccess] parameters=[ inspect.Parameter( name=name, kind=inspect.Parameter.POSITIONAL_ONLY, annotation=arg._var_type, ) for name, arg in zip( names, parse_args_spec(event.args_spec), strict=True ) ] ) return fn def get_prop_vars(self) -> list[Var | Callable]: """Get the prop vars. Returns: The prop vars. """ return [ Var( _js_expr=name, _var_type=(prop._var_type if isinstance(prop, Var) else type(prop)), ).guess_type() if isinstance(prop, Var) or not isinstance(prop, EventChain) else CustomComponent._get_event_spec_from_args_spec(name, prop) for name, prop in self.props.items() ] @functools.cache # noqa: B019 def get_component(self) -> Component: """Render the component. Returns: The code to render the component. """ return self.component_fn(*self.get_prop_vars()) CUSTOM_COMPONENTS: dict[str, CustomComponent] = {} def _register_custom_component( component_fn: Callable[..., Component], ): """Register a custom component to be compiled. Args: component_fn: The function that creates the component. Raises: TypeError: If the tag name cannot be determined. """ dummy_props = { prop: ( Var( "", _var_type=unwrap_var_annotation(annotation), ).guess_type() if not types.safe_issubclass(annotation, EventHandler) else EventSpec(handler=EventHandler(fn=lambda: [])) ) for prop, annotation in typing.get_type_hints(component_fn).items() if prop != "return" } dummy_component = CustomComponent._create( children=[], component_fn=component_fn, **dummy_props, ) if dummy_component.tag is None: raise TypeError(f"Could not determine the tag name for {component_fn!r}") CUSTOM_COMPONENTS[dummy_component.tag] = dummy_component def custom_component( component_fn: Callable[..., Component], ) -> Callable[..., CustomComponent]: """Create a custom component from a function. Args: component_fn: The function that creates the component. Returns: The decorated function. """ @wraps(component_fn) def wrapper(*children, **props) -> CustomComponent: # Remove the children from the props. props.pop("children", None) return CustomComponent._create( children=list(children), component_fn=component_fn, **props ) # Register this component so it can be compiled. _register_custom_component(component_fn) return wrapper # Alias memo to custom_component. memo = custom_component class NoSSRComponent(Component): """A dynamic component that is not rendered on the server.""" def _get_import_name(self) -> None | str: if not self.library: return None return f"${self.library}" if self.library.startswith("/") else self.library def _get_imports(self) -> ParsedImportDict: """Get the imports for the component. Returns: The imports for dynamically importing the component at module load time. """ # Next.js dynamic import mechanism. dynamic_import = {"next/dynamic": [ImportVar(tag="dynamic", is_default=True)]} # The normal imports for this component. _imports = super()._get_imports() # Do NOT import the main library/tag statically. import_name = self._get_import_name() if import_name is not None: with contextlib.suppress(ValueError): _imports[import_name].remove(self.import_var) _imports[import_name].append( imports.ImportVar( tag=None, render=False, transpile=self._should_transpile(self.library), ) ) return imports.merge_imports( dynamic_import, _imports, self._get_dependencies_imports(), ) def _get_dynamic_imports(self) -> str: opts_fragment = ", { ssr: false });" # extract the correct import name from library name base_import_name = self._get_import_name() if base_import_name is None: raise ValueError("Undefined library for NoSSRComponent") import_name = format.format_library_name(base_import_name) library_import = f"const {self.alias if self.alias else self.tag} = dynamic(() => import('{import_name}')" mod_import = ( # https://nextjs.org/docs/pages/building-your-application/optimizing/lazy-loading#with-named-exports f".then((mod) => mod.{self.tag})" if not self.is_default else "" ) return "".join((library_import, mod_import, opts_fragment)) class StatefulComponent(BaseComponent): """A component that depends on state and is rendered outside of the page component. If a StatefulComponent is used in multiple pages, it will be rendered to a common file and imported into each page that uses it. A stateful component has a tag name that includes a hash of the code that it renders to. This tag name refers to the specific component with the specific props that it was created with. """ # A lookup table to caching memoized component instances. tag_to_stateful_component: ClassVar[dict[str, StatefulComponent]] = {} # Reference to the original component that was memoized into this component. component: Component # The rendered (memoized) code that will be emitted. code: str # How many times this component is referenced in the app. references: int = 0 # Whether the component has already been rendered to a shared file. rendered_as_shared: bool = False @classmethod def create(cls, component: Component) -> StatefulComponent | None: """Create a stateful component from a component. Args: component: The component to memoize. Returns: The stateful component or None if the component should not be memoized. """ from reflex.components.core.foreach import Foreach if component._memoization_mode.disposition == MemoizationDisposition.NEVER: # Never memoize this component. return None if component.tag is None: # Only memoize components with a tag. return None # If _var_data is found in this component, it is a candidate for auto-memoization. should_memoize = False # If the component requests to be memoized, then ignore other checks. if component._memoization_mode.disposition == MemoizationDisposition.ALWAYS: should_memoize = True if not should_memoize: # Determine if any Vars have associated data. for prop_var in component._get_vars(include_children=True): if prop_var._get_all_var_data(): should_memoize = True break if not should_memoize: # Check for special-cases in child components. for child in component.children: # Skip BaseComponent and StatefulComponent children. if not isinstance(child, Component): continue # Always consider Foreach something that must be memoized by the parent. if isinstance(child, Foreach): should_memoize = True break child = cls._child_var(child) if isinstance(child, Var) and child._get_all_var_data(): should_memoize = True break if should_memoize or component.event_triggers: # Render the component to determine tag+hash based on component code. tag_name = cls._get_tag_name(component) if tag_name is None: return None # Look up the tag in the cache stateful_component = cls.tag_to_stateful_component.get(tag_name) if stateful_component is None: # Render the component as a string of javascript code. code = cls._render_stateful_code(component, tag_name=tag_name) # Set the stateful component in the cache for the given tag. stateful_component = cls.tag_to_stateful_component.setdefault( tag_name, cls( children=component.children, component=component, tag=tag_name, code=code, ), ) # Bump the reference count -- multiple pages referencing the same component # will result in writing it to a common file. stateful_component.references += 1 return stateful_component # Return None to indicate this component should not be memoized. return None @staticmethod def _child_var(child: Component) -> Var | Component: """Get the Var from a child component. This method is used for special cases when the StatefulComponent should actually wrap the parent component of the child instead of recursing into the children and memoizing them independently. Args: child: The child component. Returns: The Var from the child component or the child itself (for regular cases). """ from reflex.components.base.bare import Bare from reflex.components.core.cond import Cond from reflex.components.core.foreach import Foreach from reflex.components.core.match import Match if isinstance(child, Bare): return child.contents if isinstance(child, Cond): return child.cond if isinstance(child, Foreach): return child.iterable if isinstance(child, Match): return child.cond return child @classmethod def _get_tag_name(cls, component: Component) -> str | None: """Get the tag based on rendering the given component. Args: component: The component to render. Returns: The tag for the stateful component. """ # Get the render dict for the component. rendered_code = component.render() if not rendered_code: # Never memoize non-visual components. return None # Compute the hash based on the rendered code. code_hash = md5(str(rendered_code).encode("utf-8")).hexdigest() # Format the tag name including the hash. return format.format_state_name( f"{component.tag or 'Comp'}_{code_hash}" ).capitalize() @classmethod def _render_stateful_code( cls, component: Component, tag_name: str, ) -> str: """Render the code for a stateful component. Args: component: The component to render. tag_name: The tag name for the stateful component (see _get_tag_name). Returns: The rendered code. """ # Memoize event triggers useCallback to avoid unnecessary re-renders. memo_event_triggers = tuple(cls._get_memoized_event_triggers(component).items()) # Trigger hooks stored separately to write after the normal hooks (see stateful_component.js.jinja2) memo_trigger_hooks = [] if memo_event_triggers: # Copy the component to avoid mutating the original. component = copy.copy(component) for event_trigger, ( memo_trigger, memo_trigger_hook, ) in memo_event_triggers: # Replace the event trigger with the memoized version. memo_trigger_hooks.append(memo_trigger_hook) component.event_triggers[event_trigger] = memo_trigger # Render the code for this component and hooks. return STATEFUL_COMPONENT.render( tag_name=tag_name, memo_trigger_hooks=memo_trigger_hooks, component=component, ) @staticmethod def _get_hook_deps(hook: str) -> list[str]: """Extract var deps from a hook. Args: hook: The hook line to extract deps from. Returns: A list of var names created by the hook declaration. """ # Ensure that the hook is a var declaration. var_decl = hook.partition("=")[0].strip() if not any(var_decl.startswith(kw) for kw in ["const ", "let ", "var "]): return [] # Extract the var name from the declaration. _, _, var_name = var_decl.partition(" ") var_name = var_name.strip() # Break up array and object destructuring if used. if var_name.startswith("[") or var_name.startswith("{"): return [ v.strip().replace("...", "") for v in var_name.strip("[]{}").split(",") ] return [var_name] @staticmethod def _get_deps_from_event_trigger(event: EventChain | EventSpec | Var) -> set[str]: """Get the dependencies accessed by event triggers. Args: event: The event trigger to extract deps from. Returns: The dependencies accessed by the event triggers. """ events: list = [event] deps = set() if isinstance(event, EventChain): events.extend(event.events) for ev in events: if isinstance(ev, EventSpec): for arg in ev.args: for a in arg: var_datas = VarData.merge(a._get_all_var_data()) if var_datas and var_datas.deps is not None: deps |= {str(dep) for dep in var_datas.deps} return deps @classmethod def _get_memoized_event_triggers( cls, component: Component, ) -> dict[str, tuple[Var, str]]: """Memoize event handler functions with useCallback to avoid unnecessary re-renders. Args: component: The component with events to memoize. Returns: A dict of event trigger name to a tuple of the memoized event trigger Var and the hook code that memoizes the event handler. """ trigger_memo = {} for event_trigger, event_args in component._get_vars_from_event_triggers( component.event_triggers ): if event_trigger in { EventTriggers.ON_MOUNT, EventTriggers.ON_UNMOUNT, EventTriggers.ON_SUBMIT, }: # Do not memoize lifecycle or submit events. continue # Get the actual EventSpec and render it. event = component.event_triggers[event_trigger] rendered_chain = str(LiteralVar.create(event)) # Hash the rendered EventChain to get a deterministic function name. chain_hash = md5(str(rendered_chain).encode("utf-8")).hexdigest() memo_name = f"{event_trigger}_{chain_hash}" # Calculate Var dependencies accessed by the handler for useCallback dep array. var_deps = ["addEvents", "Event"] # Get deps from event trigger var data. var_deps.extend(cls._get_deps_from_event_trigger(event)) # Get deps from hooks. for arg in event_args: var_data = arg._get_all_var_data() if var_data is None: continue for hook in var_data.hooks: var_deps.extend(cls._get_hook_deps(hook)) memo_var_data = VarData.merge( *[var._get_all_var_data() for var in event_args], VarData( imports={"react": [ImportVar(tag="useCallback")]}, ), ) # Store the memoized function name and hook code for this event trigger. trigger_memo[event_trigger] = ( Var(_js_expr=memo_name)._replace( _var_type=EventChain, merge_var_data=memo_var_data ), f"const {memo_name} = useCallback({rendered_chain}, [{', '.join(var_deps)}])", ) return trigger_memo def _get_all_hooks_internal(self) -> dict[str, VarData | None]: """Get the reflex internal hooks for the component and its children. Returns: The code that should appear just before user-defined hooks. """ return {} def _get_all_hooks(self) -> dict[str, VarData | None]: """Get the React hooks for this component. Returns: The code that should appear just before returning the rendered component. """ return {} def _get_all_imports(self) -> ParsedImportDict: """Get all the libraries and fields that are used by the component. Returns: The import dict with the required imports. """ if self.rendered_as_shared: return { f"$/{Dirs.UTILS}/{PageNames.STATEFUL_COMPONENTS}": [ ImportVar(tag=self.tag) ] } return self.component._get_all_imports() def _get_all_dynamic_imports(self) -> set[str]: """Get dynamic imports for the component. Returns: The dynamic imports. """ if self.rendered_as_shared: return set() return self.component._get_all_dynamic_imports() def _get_all_custom_code(self) -> set[str]: """Get custom code for the component. Returns: The custom code. """ if self.rendered_as_shared: return set() return self.component._get_all_custom_code().union({self.code}) def _get_all_refs(self) -> set[str]: """Get the refs for the children of the component. Returns: The refs for the children. """ if self.rendered_as_shared: return set() return self.component._get_all_refs() def render(self) -> dict: """Define how to render the component in React. Returns: The tag to render. """ return dict(Tag(name=self.tag or "")) def __str__(self) -> str: """Represent the component in React. Returns: The code to render the component. """ from reflex.compiler.compiler import _compile_component return _compile_component(self) @classmethod def compile_from(cls, component: BaseComponent) -> BaseComponent: """Walk through the component tree and memoize all stateful components. Args: component: The component to memoize. Returns: The memoized component tree. """ if isinstance(component, Component): if component._memoization_mode.recursive: # Recursively memoize stateful children (default). component.children = [ cls.compile_from(child) for child in component.children ] # Memoize this component if it depends on state. stateful_component = cls.create(component) if stateful_component is not None: return stateful_component return component class MemoizationLeaf(Component): """A component that does not separately memoize its children. Any component which depends on finding the exact names of children components within it, should be a memoization leaf so the compiler does not replace the provided child tags with memoized tags. During creation, a memoization leaf will mark itself as wanting to be memoized if any of its children return any hooks. """ _memoization_mode = MemoizationMode(recursive=False) @classmethod def create(cls, *children, **props) -> Component: """Create a new memoization leaf component. Args: *children: The children of the component. **props: The props of the component. Returns: The memoization leaf """ comp = super().create(*children, **props) if comp._get_all_hooks(): comp._memoization_mode = dataclasses.replace( comp._memoization_mode, disposition=MemoizationDisposition.ALWAYS ) return comp load_dynamic_serializer() class ComponentVar(Var[Component], python_types=BaseComponent): """A Var that represents a Component.""" def empty_component() -> Component: """Create an empty component. Returns: An empty component. """ from reflex.components.base.bare import Bare return Bare.create("") def render_dict_to_var(tag: dict | Component | str, imported_names: set[str]) -> Var: """Convert a render dict to a Var. Args: tag: The render dict. imported_names: The names of the imported components. Returns: The Var. """ if not isinstance(tag, dict): if isinstance(tag, Component): return render_dict_to_var(tag.render(), imported_names) return Var.create(tag) if "iterable" in tag: function_return = LiteralArrayVar.create( [ render_dict_to_var(child.render(), imported_names) for child in tag["children"] ] ) func = ArgsFunctionOperation.create( (tag["arg_var_name"], tag["index_var_name"]), function_return, ) return FunctionStringVar.create("Array.prototype.map.call").call( tag["iterable"] if not isinstance(tag["iterable"], ObjectVar) else tag["iterable"].items(), func, ) if tag["name"] == "match": element = tag["cond"] conditionals = render_dict_to_var(tag["default"], imported_names) for case in tag["match_cases"][::-1]: condition = case[0].to_string() == element.to_string() for pattern in case[1:-1]: condition = condition | (pattern.to_string() == element.to_string()) conditionals = ternary_operation( condition, render_dict_to_var(case[-1], imported_names), conditionals, ) return conditionals if "cond" in tag: return ternary_operation( tag["cond"], render_dict_to_var(tag["true_value"], imported_names), render_dict_to_var(tag["false_value"], imported_names) if tag["false_value"] is not None else LiteralNoneVar.create(), ) props = {} special_props = [] for prop_str in tag["props"]: if ":" not in prop_str: special_props.append(Var(prop_str).to(ObjectVar)) continue prop = prop_str.index(":") key = prop_str[:prop] value = prop_str[prop + 1 :] props[key] = value props = LiteralObjectVar.create( {LiteralStringVar.create(k): Var(v) for k, v in props.items()} ) for prop in special_props: props = props.merge(prop) contents = tag["contents"] if tag["contents"] else None raw_tag_name = tag.get("name") tag_name = Var(raw_tag_name or "Fragment") return FunctionStringVar.create( "jsx", ).call( tag_name, props, *([Var(contents)] if contents is not None else []), *[render_dict_to_var(child, imported_names) for child in tag["children"]], ) @dataclasses.dataclass( eq=False, frozen=True, slots=True, ) class LiteralComponentVar(CachedVarOperation, LiteralVar, ComponentVar): """A Var that represents a Component.""" _var_value: BaseComponent = dataclasses.field(default_factory=empty_component) @cached_property_no_lock def _cached_var_name(self) -> str: """Get the name of the var. Returns: The name of the var. """ var_data = self._get_all_var_data() if var_data is not None: # flatten imports imported_names = {j.alias or j.name for i in var_data.imports for j in i[1]} else: imported_names = set() return str(render_dict_to_var(self._var_value.render(), imported_names)) @cached_property_no_lock def _cached_get_all_var_data(self) -> VarData | None: """Get the VarData for the var. Returns: The VarData for the var. """ return VarData.merge( self._var_data, VarData( imports=self._var_value._get_all_imports(), ), ) def __hash__(self) -> int: """Get the hash of the var. Returns: The hash of the var. """ return hash((type(self).__name__, self._js_expr)) @classmethod def create( cls, value: Component, _var_data: VarData | None = None, ): """Create a var from a value. Args: value: The value of the var. _var_data: Additional hooks and imports associated with the Var. Returns: The var. """ var_datas = [ var_data for var in value._get_vars(include_children=True) if (var_data := var._get_all_var_data()) ] return LiteralComponentVar( _js_expr="", _var_type=type(value), _var_data=VarData.merge( _var_data, *var_datas, VarData( components=(value,), ), ), _var_value=value, )