04-message-handlers

See also

examples/04-message-handlers/main.cpp

Welcome to the irsol::server::handlers subsystem!
This guide introduces you to the core concepts and practical usage of handlers and the message-handler system in the irsol framework.

What are Handlers?

Handlers are the building blocks that connect protocol messages (such as commands, assignments, and inquiries) to your application logic. Each handler is responsible for processing a specific type of protocol message and producing an appropriate response.

Handlers are typically implemented as C++ classes (deriving from a base handler template irsol::server::handlers::internal::HandlerBase), but can also be defined as lambda functions for rapid prototyping or simple use cases.

What is a MessageHandler?

The irsol::server::handlers::MessageHandler is a central registry and dispatcher. It:

• Receives parsed protocol messages and forwards them to the correct handler.
• Allows you to register, replace, or remove handlers at runtime.

Typical Workflow

1. Implement a Handler
   Create a handler class (or lambda) that processes a specific protocol message.
2. Register the Handler
   Register your handler with a MessageHandler instance, associating it with a message identifier.
3. Dispatch Messages
   When a protocol message is received, the MessageHandler looks up the handler for its identifier and invokes it, passing the message and client context.

Example

See also

examples/04-message-handlers/main.cpp See the main file in this folder for a complete example showing:

• How to define a custom handler.
• How to register it with a MessageHandler.
• How to dispatch messages and verify handler invocation.

When to Use Lambda Handlers

For simple or one-off logic, you can use a lambda handler instead of a full class. This is especially useful for:

• Prototyping new features.
• Writing test or mock handlers.
• Reducing boilerplate for trivial message processing.

For more details, see the documentation in irsol/server/handlers/base.hpp and irsol/server/handlers/lambda_handler.hpp, and the API reference.