Event-driven architecture in Node.js works by utilizing events and callbacks. Here’s a step-by-step description:
1. An event-driven programming approach is one where the flow of the program is determined by events such as user actions, sensor outputs, or messages from other programs.
1. Node.js uses an event-driven, non-blocking I/O model, which makes it lightweight and efficient.
1. An event in Node.js is any action that can be detected by the system. It could be from the system itself or from the application created, such as a click, completed file download, a hardware interruption, or a signal to the process.
1. When an event occurs, an event handler (a callback function) is called, hence the term “event-driven”. The event handler is a function that will be called when an event of the type it is attached to is triggered.
1. Node.js has a built-in module, “EventEmitter”, to create, fire, and handle events easily.
1. For instance, a simple file server can be set up using Node.js where an event is triggered and a callback function is executed as soon as the server starts listening.
1. When these events get triggered, they get pushed into an event queue. These events run one after the other, not simultaneously. This is a feature implemented in Node.js to ensure no blocking occurs and the application can continue to run while it’s waiting for other things to finish. This is known as the event loop.
1. In summary, the event-driven architecture in Node.js is a way to handle program flow based on events and their callbacks. This architecture allows Node.js to handle many operations simultaneously without blocking the main thread, making it highly efficient for handling I/O processes.
