adding multiple event listeners to one element

Question

So my dilemma is that I don\'t want to write the same code twice. Once for the click event and another for the touchstart event.

Here is the original co

Answer 1

This is my solution in which I deal with multiple events in my workflow.

let h2 = document.querySelector("h2");

function addMultipleEvents(eventsArray, targetElem, handler) {
        eventsArray.map(function(event) {
            targetElem.addEventListener(event, handler, false);
        }
    );
}
let counter = 0;
function countP() {
    counter++;
    h2.innerHTML = counter;
}

// magic starts over here...
addMultipleEvents(['click', 'mouseleave', 'mouseenter'], h2, countP);

<h1>MULTI EVENTS DEMO - If you click, move away or enter the mouse on the number, it counts...</h1>

<h2 style="text-align:center; font: bold 3em comic; cursor: pointer">0</h2>

Answer 2

For large numbers of events this might help:

var element = document.getElementById("myId");
var myEvents = "click touchstart touchend".split(" ");
var handler = function (e) {
    do something
};

for (var i=0, len = myEvents.length; i < len; i++) {
    element.addEventListener(myEvents[i], handler, false);
}

Update 06/2017:

Now that new language features are more widely available you could simplify adding a limited list of events that share one listener.

const element = document.querySelector("#myId");

function handleEvent(e) {
    // do something
}
// I prefer string.split because it makes editing the event list slightly easier

"click touchstart touchend touchmove".split(" ")
    .map(name => element.addEventListener(name, handleEvent, false));

If you want to handle lots of events and have different requirements per listener you can also pass an object which most people tend to forget.

const el = document.querySelector("#myId");

const eventHandler = {
    // called for each event on this element
    handleEvent(evt) {
        switch (evt.type) {
            case "click":
            case "touchstart":
                // click and touchstart share click handler
                this.handleClick(e);
                break;
            case "touchend":
                this.handleTouchend(e);
                break;
            default:
                this.handleDefault(e);
        }
    },
    handleClick(e) {
        // do something
    },
    handleTouchend(e) {
        // do something different
    },
    handleDefault(e) {
        console.log("unhandled event: %s", e.type);
    }
}

el.addEventListener(eventHandler);

Update 05/2019:

const el = document.querySelector("#myId");

const eventHandler = {
    handlers: {
        click(e) {
            // do something
        },
        touchend(e) {
            // do something different
        },
        default(e) {
            console.log("unhandled event: %s", e.type);
        }
    },
    // called for each event on this element
    handleEvent(evt) {
        switch (evt.type) {
            case "click":
            case "touchstart":
                // click and touchstart share click handler
                this.handlers.click(e);
                break;
            case "touchend":
                this.handlers.touchend(e);
                break;
            default:
                this.handlers.default(e);
        }
    }
}

Object.keys(eventHandler.handlers)
    .map(eventName => el.addEventListener(eventName, eventHandler))

Answer 3

This mini javascript libary (1.3 KB) can do all these things

https://github.com/Norair1997/norjs/

nor.event(["#first"], ["touchstart", "click"], [doSomething, doSomething]);

Answer 4

document.getElementById('first').addEventListener('touchstart',myFunction);

document.getElementById('first').addEventListener('click',myFunction);
    
function myFunction(e){
  e.preventDefault();e.stopPropagation()
  do_something();
}    

You should be using e.stopPropagation() because if not, your function will fired twice on mobile

Answer 5

Maybe you can use a helper function like this:

// events and args should be of type Array
function addMultipleListeners(element,events,handler,useCapture,args){
  if (!(events instanceof Array)){
    throw 'addMultipleListeners: '+
          'please supply an array of eventstrings '+
          '(like ["click","mouseover"])';
  }
  //create a wrapper to be able to use additional arguments
  var handlerFn = function(e){
    handler.apply(this, args && args instanceof Array ? args : []);
  }
  for (var i=0;i<events.length;i+=1){
    element.addEventListener(events[i],handlerFn,useCapture);
  }
}

function handler(e) {
  // do things
};

// usage
addMultipleListeners(
    document.getElementById('first'),
    ['touchstart','click'],
    handler,
    false);

[Edit nov. 2020] This answer is pretty old. The way I solve this nowadays is by using an actions object where handlers are specified per event type, a data-attribute for an element to indicate which action should be executed on it and one generic document wide handler method (so event delegation).

const firstElemHandler = (elem, evt) =>
  elem.textContent = `You ${evt.type === "click" ? "clicked" : "touched"}!`;
const actions = {
  click: {
    firstElemHandler,
  },
  touchstart: {
    firstElemHandler,
  },
  mouseover: {
    firstElemHandler: elem => elem.textContent = "Now ... click me!",
    outerHandling: elem => {
      console.clear();
      console.log(`Hi from outerHandling, handle time ${
        new Date().toLocaleTimeString()}`);
    },
  }
};

Object.keys(actions).forEach(key => document.addEventListener(key, handle));

function handle(evt) {
  const origin = evt.target.closest("[data-action]");
  return origin &&
    actions[evt.type] &&
    actions[evt.type][origin.dataset.action] &&
    actions[evt.type][origin.dataset.action](origin, evt) ||
    true;
}

[data-action]:hover {
  cursor: pointer;
}

<div data-action="outerHandling">
  <div id="first" data-action="firstElemHandler">
    <b>Hover, click or tap</b>
  </div>
  this is handled too (on mouse over)
</div>

Answer 6

Unless your do_something function actually does something with any given arguments, you can just pass it as the event handler.

var first = document.getElementById('first');
first.addEventListener('touchstart', do_something, false);
first.addEventListener('click', do_something, false);