js_on_off

js_on_off is a tiny js library (< 3kb) created to have jQuery on() and off() functions with no dependencies. Main features are included:

• JQuery syntax
• event delegation
• remove all event listeners with off
• Works with document, Element, HtmlElement, NodeList and HTMLCollection
• event namespacing

Installation

Use the package manager npm to install js_on_off.

npm install js_on_off --save

Alternatively, you can just download this project from git. Https:

https://github.com/Sanni87/js_on_off.git

Github CLI:

gh repo clone Sanni87/js_on_off

Usage

Once downloaded, there are 2 ways to include this library in your project.

Direct script

<script src="node_modules/js_on_off/dist/on_off.min.js"></script>

You can do it from an html or of course you can reference the script to include on a custom bundle if you want it.

Import module

If you are using tools like webpack, babel, gulp or similars, you can also import the library as follows:

import { on, off } from  'js_on_off';

Examples

Depending on how the script is included, the syntax of the functions changes slightly. Of course, the functionality doesn't change.

Examples with direct script

As we have said, first of all we must to include the script

<script src="node_modules/js_on_off/dist/on_off.min.js"></script>

Then we can use on or off with direct binding:

var button = document.querySelector("#btn");
var handler = function (event) {
    //do stuff
};

//direct binding with anonymous function
button.on('click', function (event) {
    //'event' is the same than .addEventListener() handler param
});

//direct binding with named function
button.on('click', handler); 

//direct unbinding
button.off('click', handler); //unbind just "handler" for click event on button
button.off('click'); //unbind all click events on button
button.off(); //unbind everything on button

Event delegation:

<!--[...]-->
<div id="buttonParent">
   <button id="button">Click me</button>
</div>
<!--[...]-->
<script>
var parent = document.querySelector("#buttonParent");
var handler = function (event) {
    //do stuff
};

//delegate binding with anonymous function
//In this case click event is attached to parent, but handler will be executed when button is clicked
parent.on('click', '#button', function (event) {
    //'event' is the same than .addEventListener() handler param
});

//direct binding with named function
button.on('click', '#button', handler); 

//direct unbinding
parent.off('click', '#button', handler); //unbind just "handler" for click event on button
parent.off('click', '#button'); //unbind all click events on button
parent.off('click'); //unbind direct click events on parent and also every delegated binding attached to parent (in this case on '#button' click)
parent.off(); //unbind every event, direct or delegated, attached to parent
</script>

Namespacing:

var button = document.querySelector("#btn");
var handler = function (event) {
    //do stuff
};

var handler2 = function (event) {
    //do stuff
};

var handler3 = function (event) {
    //do stuff
};

//bind with namespace
button.on('click.dontRemove', handler); 
button.on('click.removeThis', handler2); 
button.on('mouseup.removeThis', handler3)

//unbind with namespace
button.off('click.removeThis'); //unbind handler2
button.off('.removeThis'); //unbind handler2 and handler3

Examples importing module

If we import the module in a js file, on and off functions will not be attached to NodeList, HtmlElement and so on, so the syntax is a bit different. Here are the same samples using import:

import { on, off } from  'js_on_off';

var parent = document.querySelector("#buttonParent");
var button = document.querySelector("#btn");
var handler = function (event) {
    //do stuff
};

//binding
on(button, 'click', function (event) {
    //'event' is the same than .addEventListener() handler param
});
on(button, 'click', handler); 
on(button, 'click', '#button', handler);
on(button, 'click.removeThis', handler); 

//unbinding
off(parent, 'click', '#button', handler); //unbind just "handler" for click event on button
off(parent, 'click', '#button'); //unbind all click events on button
off(button, 'click', handler); //unbind just "handler" for click event on button
off(button, 'click'); //unbind all click events on button
off(button, 'click.removeThis'); //unbind attached 'click' events with 'removeThis' namespace on button
off(button, '.removeThis'); //unbind all events with removeThis namespace on button
off(button); //unbind everything on button

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT