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Simple EventEmmiter for Go Programming Language. Inspired by [Nodejs EventEmitter](https://nodejs.org/api/events.html). For **Generics** support please wait until go1.18 stable is released, until then switch to [dev branch](https://github.com/kataras/go-events/tree/dev) instead. Overview ------------ `New() EventEmmiter // New returns a new, empty, EventEmmiter` ```go // AddListener is an alias for .On(eventName, listener). AddListener(EventName, ...Listener) // Emit fires a particular event, // Synchronously calls each of the listeners registered for the event named // eventName, in the order they were registered, // passing the supplied arguments to each. Emit(EventName, ...interface{}) // EventNames returns an array listing the events for which the emitter has registered listeners. // The values in the array will be strings. EventNames() []EventName // GetMaxListeners returns the max listeners for this emmiter // see SetMaxListeners GetMaxListeners() int // ListenerCount returns the length of all registered listeners to a particular event ListenerCount(EventName) int // Listeners returns a copy of the array of listeners for the event named eventName. Listeners(EventName) []Listener // On registers a particular listener for an event, func receiver parameter(s) is/are optional On(EventName, ...Listener) // Once adds a one time listener function for the event named eventName. // The next time eventName is triggered, this listener is removed and then invoked. Once(EventName, ...Listener) // RemoveAllListeners removes all listeners, or those of the specified eventName. // Note that it will remove the event itself. // Returns an indicator if event and listeners were found before the remove. RemoveAllListeners(EventName) bool // Clear removes all events and all listeners, restores Events to an empty value Clear() // SetMaxListeners obviously this function allows the MaxListeners // to be decrease or increase. Set to zero for unlimited SetMaxListeners(int) // Len returns the length of all registered events Len() int ``` ```go import "github.com/kataras/go-events" // initialize a new EventEmmiter to use e := events.New() // register an event with name "my_event" and one listener e.On("my_event", func(payload ...interface{}) { message := payload[0].(string) print(message) // prints "this is my payload" }) // fire the 'my_event' event e.Emit("my_event", "this is my payload") ``` Default/global EventEmmiter ```go // register an event with name "my_event" and one listener to the global(package level) default EventEmmiter events.On("my_event", func(payload ...interface{}) { message := payload[0].(string) print(message) // prints "this is my payload" }) // fire the 'my_event' event events.Emit("my_event", "this is my payload") ``` Remove an event ```go events.On("my_event", func(payload ...interface{}) { // first listener... },func (payload ...interface{}){ // second listener... }) println(events.Len()) // prints 1 println(events.ListenerCount("my_event")) // prints 2 // Remove our event, when/if we don't need this or we want to clear all of its listeners events.RemoveAllListeners("my_event") println(events.Len()) // prints 0 println(events.ListenerCount("my_event")) // prints 0 ``` Installation ------------ The only requirement is the [Go Programming Language](https://golang.org/dl). ```bash $ go get -u github.com/kataras/go-events ``` FAQ ------------ Explore [these questions](https://github.com/kataras/go-events/issues?go-events=label%3Aquestion) or navigate to the [community chat][Chat]. Versioning ------------ Current: v0.0.3 Read more about Semantic Versioning 2.0.0 - http://semver.org/ - https://en.wikipedia.org/wiki/Software_versioning - https://wiki.debian.org/UpstreamGuide#Releases_and_Versions Contributing ------------ If you are interested in contributing to the go-events project, please prepare a PR. License ------------ This project is licensed under the MIT License. License can be found [here](LICENSE).