I was going through the history of dropdown.js in bootstrap and came across the following change History file on git, here:

$this.focus()   // focus() being changed to trigger('focus');
$this.trigger('focus')

Now, the guy here has left a ment about the change saying:

Makes life for people with custom jQuery builds excluding event aliases much easier.

I don't quite understand what's the difference here between using focus() or trigger('focus'), as for me both have the same effect; why has the author chosen such a change?

I was going through the history of dropdown.js in bootstrap and came across the following change History file on git, here:

$this.focus()   // focus() being changed to trigger('focus');
$this.trigger('focus')

Now, the guy here has left a ment about the change saying:

Makes life for people with custom jQuery builds excluding event aliases much easier.

I don't quite understand what's the difference here between using focus() or trigger('focus'), as for me both have the same effect; why has the author chosen such a change?

• javascript
• jquery
• twitter-bootstrap

Share Improve this question Follow edited Sep 24, 2018 at 17:12 BenMorel 36.6k5151 gold badges205205 silver badges336336 bronze badges asked Apr 7, 2015 at 22:20 Alexander SolonikAlexander Solonik 10.3k1919 gold badges8686 silver badges185185 bronze badges 2

• 3 huh , why the downvote ?? – Alexander Solonik Commented Apr 7, 2015 at 22:25
• i am here to spead love nd upvotes ... and brotherhood , haters gonna hate . – Alexander Solonik Commented Apr 7, 2015 at 22:34

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2 Answers 2

Sorted by: Reset to default 6

https://github./jquery/jquery#modules.

If you are making a custom jQuery build and exclude event/alias module - you won't have shortcuts to events (e.g. .click(), .focus(), .ready(), etc).

So you'll have to use .on('eventName', handler) for event binding and consequently .trigger('eventName') to trigger jQuery event.

People with custom jQuery builds could create or modify their own focus() functions intended to do whatever they want. Imagine if you create your own focus() which allows lot of parameters and chains multiple callback; it would be a mess when you bine its usage with the jQuery focus() basic function.

When you use a trigger it's qute obvious you're going to trigger an action; in this case, to focus an element.

Beside of that, using the trigger() functions makes the code a little easier to understand.