Liev NPM | npm.io

Liev

Listen to events – A simple, small, and performant utility for listening to and attaching native and custom DOM events.

Liev attaches events internally to a parent element (document.documentElement per default), so you don't need to attach new event listeners when new HTMLElements's get added to the DOM.
Liev attaches as little event listeners as possible by using event delegation to make your web app more performant (You can read about that idea here).
Liev decides whether you're listener should be passive or not, so You don't have to think about it (Liev can not look into nested functions, so sometimes you have to set it to false when you call Event.preventDefault()).

npm i liev

Look in the dist folder for the build files and more information.

target HTMLElement The element that triggered the event
event Event An object based on Event describing the event that has occurred

Adds a listener

type String A case-sensitive string representing the event type to listen for
selector String A string containing one or more selectors to match, use an empty string to match everything
callback EventHandler A function that gets executed when an event of the specified type occurs
options Object (optional, default {})
- options.once Boolean whether a listener should only be executed once or not (optional, default false)
- options.element HTMLElement the parent element to that the listener is attached (optional, default document.documentElement)
- options.passive Boolean? Whether a listener should be passive or not, looks per default into a stringified version of your callback to decide based on your code if it should be passive or not

Returns Boolean true if added, false if done nothing

Removes a listener that was added through the "on" method

type String The type that was used on the "on" method
selector String The selector that was used on the "on" method
callback EventHandler The function that was used on the "on" method
options Object (optional, default {})
- options.once Boolean The value that was used on the "on" method (optional, default false)
- options.element HTMLElement The element that was used on the "on" method (optional, default document.documentElement)
- options.passive Boolean? The value that was used on the "on" method

Returns Boolean true if removed, false if done nothing

Emits an event from an element

event String A case-sensitive string representing the event type to emit (can, or ideally should be, a custom one)
element HTMLElement The element from that the event is detached (optional, default document.documentElement)
detail any an info to send with the event (optional, default null)

Returns Boolean true if emitted, false if done nothing