Exceptions | message-bus | Webware Documentation

All exceptions live under Webware\MessageBus\Exception.

Exception Extends / Implements Thrown when

Exception	Extends / Implements	Thrown when
`InvalidConfigurationException`	`InvalidArgumentException`	Configuration is missing or malformed, a message has no `command_map`/`query_map` entry, or a resolved handler service doesn't implement `MessageHandlerInterface` (`MessageHandlerResolver`, `MiddlewarePipeFactory`).
`ServiceNotFoundException`	`RuntimeException`, `Psr\Container\NotFoundExceptionInterface`	A required service (`config`, a mapped handler, or `MiddlewarePipelineInterface`) isn't registered in the container (`MessageHandlerResolver`, `Container\MessageBusFactory`).
`MessageException`	`RuntimeException`	The pipeline reaches `Handler\EmptyPipelineHandler` without ever producing a `ResultInterface`.
`NextHandlerAlreadyCalledException`	`DomainException`	`Next::handle()` is invoked more than once on the same instance.

InvalidConfigurationException

InvalidArgumentException

Configuration is missing or malformed, a message has no command_map/query_map entry, or a resolved handler service doesn't implement MessageHandlerInterface (MessageHandlerResolver, MiddlewarePipeFactory).

ServiceNotFoundException

RuntimeException, Psr\Container\NotFoundExceptionInterface

A required service (config, a mapped handler, or MiddlewarePipelineInterface) isn't registered in the container (MessageHandlerResolver, Container\MessageBusFactory).

MessageException

RuntimeException

The pipeline reaches Handler\EmptyPipelineHandler without ever producing a ResultInterface.

NextHandlerAlreadyCalledException

DomainException

Next::handle() is invoked more than once on the same instance.

Each exception exposes named static constructors (e.g. ServiceNotFoundException::fromService(), InvalidConfigurationException::fromUnMappedMessage()) rather than public constructors, keeping error messages consistent at every call site.