Event-Driven Programming Pattern

An Event-Driven Programming Pattern is a programming pattern that implements the observer pattern to structure program flow around detecting and responding to computing events.

• Context:
  • It can (typically) structure program flow through:
    • Event Loop for event detection
    • Callback Functions for event handling
    • Event Queue for event processing
  • It can (typically) handle event types such as:
    • User Input Events from interface interactions
    • System Events from operating system
    • Hardware Events from device drivers
  • It can (often) implement event mechanisms using:
    • Message Loop for application events
    • Hardware Interrupts for embedded systems
    • Event Listeners for web applications
  • ...
• Examples:
  • GUI Programming, such as:
    • JavaScript Events for web browsers
    • Window Events for desktop applications
    • Mobile Events for touch interfaces
  • System Programming, such as:
    • Device Driver Events
    • Network Events
    • File System Events
  • ...
• See: Closure (Computer Science), Event-Driven Architecture, Event (Computing), Message Passing, Thread (Computer Science), Graphical User Interfaces, Web Applications, User Input.

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References

2017

• (Wikipedia, 2017) ⇒ https://en.wikipedia.org/wiki/event-driven_programming Retrieved:2017-3-31.
  • In computer programming, event-driven programming is a programming paradigm in which the flow of the program is determined by events such as user actions (mouse clicks, key presses), sensor outputs, or messages from other programs/threads. Event-driven programming is the dominant paradigm used in graphical user interfaces and other applications (e.g. JavaScript web applications) that are centered on performing certain actions in response to user input. This is also true of programming for device drivers (e.g. P in USB device driver stacks )

    In an event-driven application, there is generally a main loop that listens for events, and then triggers a callback function when one of those events is detected. In embedded systems the same may be achieved using hardware interrupts instead of a constantly running main loop. Event-driven programs can be written in any programming language, although the task is easier in languages that provide high-level abstractions, such as closures.

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