Jquery - Perform callback after append

问题

I am appending content to a list using:

  $('a.ui-icon-cart').click(function(){
         $(this).closest('li').clone().appendTo('#cart ul');
  });

I want to perform further functions to the appended content (change class, apply animations etc)

How can I perform a callback on this function that will allow me to perform functions on the appended data?

回答1:

jQuery's .each() takes a callback function and applies it to each element in the jQuery object.

Imagine something like this:

$('a.ui-icon-cart').click(function(){
  $(this).closest('li').clone().appendTo('#cart ul').each(function() {
    $(this).find('h5').remove(); 
    $(this).find('img').css({'height':'40px', 'width':'40px'});
    $(this).find('li').css({'height':'60px', 'width':'40px'});
  });
});

You could also just store the result and work on it instead:

$('a.ui-icon-cart').click(function(){
  var $new = $(this).closest('li').clone().appendTo('#cart ul')
  $new.find('h5').remove(); 
  $new.find('img').css({'height':'40px', 'width':'40px'});
  $new.find('li').css({'height':'60px', 'width':'40px'});
});

I would also suggest that instead of mofiying the CSS like that you just add a class to your cloned li like this:

$(this).closest('li').clone().addClass("new-item").appendTo('#cart ul');

Then setup some styles like:

.new-item img, .new-item li { height: 40px; width: 40px; }
.new-item h5 { display: none }

回答2:

Unfortunatly adding callbacks to dom operations is not something that can be done in a neat fashion using javascript. For this reason it is not in the jQuery library. A settimeout with the timer "1ms" however always puts the function in the settimeout on the bottom of the call stack. This does work! The underscore.js library uses this technique in _.defer, which does exactly what you want.

$('a.ui-icon-cart').click(function(){
    $(this).closest('li').clone().appendTo('#cart ul');
    setTimeout(function() {
        // The LI is now appended to #cart UL and you can mess around with it.
    }, 1);
});

回答3:

You can just keep chaining further operations at the semicolon.

$(this).closest('li').clone().appendTo('#cart ul').addClass('busy').fade('fast');

etc

回答4:

In jquery you could use $() just after your appending contents code. This way you can be sure that the content is loaded and the DOM is ready before performing any tasks on the appended content.

$(function(){
//code that needs to be executed when DOM is ready, after manipulation
});

$() calls a function that either registers a DOM-ready callback (if a function is passed to it) or returns elements from the DOM (if a selector string or element is passed to it)

You can find more here
difference between $ and $() in jQuery
http://api.jquery.com/ready/

来源：https://stackoverflow.com/questions/3113853/jquery-perform-callback-after-append

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