Unable to get jQuery on() to register dynamically

2019-02-18 02:18发布

问题:

I'm quite new to the on() method in jQuery but the time has come for me to need to use it.

I've two functions for clicking on specific buttons. Each function works on any elements originally on the page but not on any dynamically added content (more of the same buttons). I understand I need to use the on() function after reading other answers on here and on Google but am having trouble still. Anyway, code:

jQuery("ul#THEBUTTONS").on({
    click: function(event){
        event.preventDefault();
        console.log("apaz clicked");
    }
}, "a.azaz");


jQuery("ul#THEBUTTONS").on({
    click: function(event){
        event.preventDefault();
        console.log("mapaz clicked");
    }
}, "a.mapaz");

Any help would be immensely appreciated, tearing my hair out here.

回答1:

.on() essentially has two flavors: one which acts like .bind(), and another which acts like .delegate().

For your problem, you want to use the delegate version. As a reference, on signatures are like this:

// bind
$(element-selector).on(event, handler)

// delegate
$(container-selector).on(event, element-selector, handler)

The best way to get up to speed with this is probably to read up on delegate, what it is, how its used, and then apply that to on.



回答2:

There are two ways to use .on(), and you're using the wrong type.

You can bind event handlers directly to elements using $('selector for elements you want the event handler bound to').on('event', function() {...});

Or, you can delegate events, by calling .on() on a wrapper element that will contain all of the dynamically added elements, such as a div or, in the worst case, the <body> element. Code would look something like this:

<div id="wrapper">
    <a href="#" class="link">Test link</a>
</div>

$('#wrapper').on('click', '.link', function(e) {
    // code to handle the click event on the link here
});

The event handler is actually handled by the <div id="wrapper"> element once the event has bubbled up to it, but the function is only called if the original target matches the selector provided. With this method, you can dynamically add additional elements with the class link to the div, and the function will also run when they're clicked on.