[javascript] How do I attach events to dynamic HTML elements with jQuery?

Suppose I have some jQuery code that attaches an event handler to all elements with class .myclass.

For example:

$(function(){
    $(".myclass").click( function() {
        // do something
    });
});

And my HTML might be as follows:

<a class="myclass" href="#">test1</a>
<a class="myclass" href="#">test2</a>
<a class="myclass" href="#">test3</a>

That works with no problem. However, consider if the .myclass elements were written to the page at some future time.

For example:

<a id="anchor1" href="#">create link dynamically</a>
<script type="text/javascript">
$(function(){
    $("#anchor1").click( function() {
        $("#anchor1").append('<a class="myclass" href="#">test4</a>');
    });
});
</script>

In this case, the test4 link is created when a user clicks on a#anchor1.

The test4 link does not have the click() handler associated with it, even though it has class="myclass".

Basically, I would like to write the click() handler once and have it apply to both content present at page load, and content brought in later via AJAX / DHTML. Any idea how I can fix this?

You can bind a single click event to a page for all elements, no matter if they are already on that page or if they will arrive at some future time, like that:

$(document).bind('click', function (e) {
   var target = $(e.target);
   if (target.is('.myclass')) {
      e.preventDefault(); // if you want to cancel the event flow
      // do something
   } else if (target.is('.myotherclass')) {
      e.preventDefault();
      // do something else
   }
});

Been using it for a while. Works like a charm.

In jQuery 1.7 and later, it is recommended to use .on() in place of bind or any other event delegation method, but .bind() still works.

You want to use the live() function. See the docs.

For example:

$("#anchor1").live("click", function() {
    $("#anchor1").append('<a class="myclass" href="#">test4</a>');
});

After jQuery 1.7 the preferred methods are .on() and .off()

Sean's answer shows an example.

Now Deprecated:

Use the jQuery functions .live() and .die(). Available in jQuery 1.3.x

From the docs:

To display each paragraph's text in an alert box whenever it is clicked:

$("p").live("click", function(){
  alert( $(this).text() );
});

Also, the livequery plugin does this and has support for more events.

If you're adding a pile of anchors to the DOM, look into event delegation instead.

Here's a simple example:

$('#somecontainer').click(function(e) {   
  var $target = $(e.target);   
  if ($target.hasClass("myclass")) {
    // do something
  }
});

Binds a handler to an event (like click) for all current - and future - matched element. Can also bind custom events.

link text

$(function(){
    $(".myclass").live("click", function() {
        // do something
    });
});

Sometimes doing this (the top-voted answer) is not always enough:

$('body').on('click', 'a.myclass', function() {
    // do something
});

This can be an issue because of the order event handlers are fired. If you find yourself doing this, but it is causing issues because of the order in which it is handled.. You can always wrap that into a function, that when called "refreshes" the listener.

For example:

function RefreshSomeEventListener() {
    // Remove handler from existing elements
    $("#wrapper .specific-selector").off(); 

    // Re-add event handler for all matching elements
    $("#wrapper .specific-selector").on("click", function() {
        // Handle event.
    }
}

Because it is a function, whenever I set up my listener this way, I typically call it on document ready:

$(document).ready(function() {
    // Other ready commands / code

    // Call our function to setup initial listening
    RefreshSomeEventListener();
});

Then, whenever you add some dynamically added element, call that method again:

function SomeMethodThatAddsElement() {
    // Some code / AJAX / whatever.. Adding element dynamically

    // Refresh our listener, so the new element is taken into account
    RefreshSomeEventListener();
}

Hopefully this helps!

Regards,

If your on jQuery 1.3+ then use .live()

Binds a handler to an event (like click) for all current - and future - matched element. Can also bind custom events.