pyqt_reactive.services.enum_dispatch_service

Abstract base class for enum-driven polymorphic dispatch services.

This ABC eliminates duplication across services that use the same pattern: 1. Define an enum for strategies/types 2. Create a dispatch table mapping enum values to handler methods 3. Determine which strategy to use based on input 4. Dispatch to the appropriate handler

Services using this pattern: - ParameterResetService (ResetStrategy enum) - NestedValueCollectionService (ValueCollectionStrategy enum) - Widget creation (WidgetCreationType enum)

Benefits: - Single source of truth for dispatch pattern - Enforces consistent structure across services - Reduces boilerplate in service implementations - Makes adding new services trivial

Example

class MyStrategy(Enum):

TYPE_A = “type_a” TYPE_B = “type_b”

class MyService(EnumDispatchService[MyStrategy]):

def __init__(self):

super().__init__() self._register_handlers({

MyStrategy.TYPE_A: self._handle_type_a, MyStrategy.TYPE_B: self._handle_type_b,

})

def _determine_strategy(self, context, **kwargs) -> MyStrategy:

# Logic to determine which strategy to use return MyStrategy.TYPE_A if some_condition else MyStrategy.TYPE_B

def _handle_type_a(self, context, **kwargs):

# Handler implementation pass

def _handle_type_b(self, context, **kwargs):

# Handler implementation pass

def process(self, context, **kwargs):

# Public API - uses dispatch return self.dispatch(context, **kwargs)

Classes

EnumDispatchService()

Abstract base class for services using enum-driven polymorphic dispatch.

class pyqt_reactive.services.enum_dispatch_service.EnumDispatchService

Abstract base class for services using enum-driven polymorphic dispatch.

Subclasses must: 1. Define a strategy enum (e.g., ResetStrategy, ValueCollectionStrategy) 2. Implement _determine_strategy() to select the appropriate strategy 3. Register handlers in __init__() using _register_handlers() 4. Implement handler methods for each strategy

The dispatch() method handles the actual dispatching logic.

__init__()

Initialize the service with an empty handler registry.

dispatch(*args, **kwargs) → Any

Dispatch to the appropriate handler based on determined strategy.

This is the core dispatch logic that: 1. Determines the strategy using _determine_strategy() 2. Looks up the handler in the registry 3. Calls the handler with the provided arguments

Parameters:

• *args – Positional arguments to pass to the handler

• **kwargs – Keyword arguments to pass to the handler

Returns:

Result from the handler method

Raises:

KeyError – If strategy is not registered in handlers

get_registered_strategies() → list[StrategyEnum]

Get list of all registered strategies.

Returns:

List of strategy enum values that have registered handlers

has_strategy(strategy: StrategyEnum) → bool

Check if a strategy has a registered handler.

Parameters:

strategy – Strategy enum value to check

Returns:

True if strategy has a registered handler, False otherwise