perhook

Perhook is a design approach in software engineering that assigns hooking points—callbacks or extension points—on a per-instance basis rather than globally. This allows each object, component, or module to expose its own set of hooks that can be customized independently of other instances.

Origin: The term combines per- with hook, indicating scope granularity. It emerged in discussions of component libraries and plugin systems seeking finer-grained extensibility.

Implementation: A perhook system maintains a per-instance registry of callbacks. When an event occurs, the system looks up the hooks for that instance and executes them in a defined order. Lifecycle management ensures that hooks are registered and unregistered with the corresponding instance to prevent leaks.

Examples: In UI frameworks, perhook can let each widget define its own event handlers or analytics hooks; in data processing pipelines, perhook can customize per-record processing.

Advantages and limitations: Advantages include isolation, customization, easier testing, and less risk of global side effects. Trade-offs include added memory usage, complexity, and potential inconsistencies if per-instance hooks diverge widely.

See also: hook, event listener, plugin architecture, per-instance state.