Toggling dropdowns using jQuery, with binding and unbinding

Question

This code is used to toggle some dropdowns. I've added the click event on the document to close the dropdown on click outside, but I'm not sure if I'm doing it the right way. I want it to be optimized for better performance.

Let me know if you have a better way to bind/unbind the events.

$('.header-top-bar .toggle').each(function (index) {
 var $this = $(this),
 $parent = $this.parent(),
 $dropdown = $this.siblings('.toggle-content');
 $this.on('click.toggle' + index, function (event) {
 event.preventDefault();
 $dropdown.toggleClass('isOpen');
 // Outside
 $document.on('click.toggle' + index, function (event) {
 if (!$(event.target).closest($parent).length) {
 $dropdown.removeClass('isOpen');
 $document.off('click.toggle' + index);
 }
 });
 });
});

jsFiddle

Answer 1

First, regarding readability, I suggest changing the following names:

• $dropdown -> $content
• .toggle (class) -> .togglable
• .toggle (namespace) -> .toggling
• .isOpen -> isToggleOpen

On the other hand this can be achieved with reduced code (and less internal working impact), with only one event binded:

var $togglables = $('.togglable-content');
$(document).on('click.toggling', function (event) {
 var $target = $(event.target),
 $content = $target.siblings('.togglable-content');
 if (!$target.hasClass('isTogglableOpen')) {
 $togglables.not($content).removeClass('isTogglableOpen');
 $content.toggleClass('isTogglableOpen');
 return false;
 }
});

Here is the modified fiddle.

• programking: Very nice answer...
• Roamer-1888: Or, if you like one-liners ...
• cFreed: @Roamer-1888 Oh yes, I retain good ideas: 1) reducing internal work by using next() rather than siblings(); 2) the trick of toggling involved element first inside of the not() definition. On the other hand, I prefer keeping $toggables definition outside, to evaluate it only once.
• Roamer-1888: @cFreed, yes for sure, I'm not sure I would go quite that far in deployed code.
• Valeriu Timbuc: @cFreed Thanks for your input. I am not sure what has more impact on the dom, but from your answer I see that every time a click happens you run the code to check if the click is on the togglable button. Isn't that worst in terms of performance? On my original code I only bind the click on dom once the togglable is open and unbind it once is closed. I would prefer something more similar to that. Also there's an issue with your code, if you click inside the togglable content it closes. Thanks again.

Answer 2

I ended using this code, once the dropdown is closed no more events run.

$('.header-top-bar .toggle').on('click', function (event) {
 event.preventDefault();
 var $this = $(this),
 $content = $this.next('.toggle-content');
 if (!$content.hasClass('isOpen')) {
 $content.addClass('isOpen');
 setTimeout(function () {
 $document.on('click.headerToggle', function (event) {
 if (!$(event.target).closest($content).length) {
 $content.removeClass('isOpen');
 $document.off('click.headerToggle');
 }
 });
 }, 10);
 }
});

Thank you all for your help.

Fiddle

• cFreed: Warning: this doen't work at all. See jsfiddle.net/ryy1yr0j/12.
• Valeriu Timbuc: @cFreed Was missing the $document var, fixed. jsfiddle.net/ryy1yr0j/14