I read this question and implemented the approach that has been stated regarding setting the response HTTP status code to 278 in order to avoid the browser transparently handling the redirects. Even though this worked, I was a little dissatisfied as it is a bit of a hack.
After more digging around, I ditched this approach and used JSON. In this case, all responses to AJAX requests have the status code 200 and the body of the response contains a JSON object that is constructed on the server. The JavaScript on the client can then use the JSON object to decide what it needs to do.
I had a similar problem to yours. I perform an AJAX request that has 2 possible responses: one that redirects the browser to a new page and one that replaces an existing HTML form on the current page with a new one. The jQuery code to do this looks something like:
$.ajax({
type: "POST",
url: reqUrl,
data: reqBody,
dataType: "json",
success: function(data, textStatus) {
if (data.redirect) {
// data.redirect contains the string URL to redirect to
window.location.href = data.redirect;
} else {
// data.form contains the HTML for the replacement form
$("#myform").replaceWith(data.form);
}
}
});
The JSON object "data" is constructed on the server to have 2 members: data.redirect
and data.form
. I found this approach to be much better.
Modern jQuery
Use .prop()
:
$('.myCheckbox').prop('checked', true);
$('.myCheckbox').prop('checked', false);
DOM API
If you're working with just one element, you can always just access the underlying HTMLInputElement
and modify its .checked
property:
$('.myCheckbox')[0].checked = true;
$('.myCheckbox')[0].checked = false;
The benefit to using the .prop()
and .attr()
methods instead of this is that they will operate on all matched elements.
jQuery 1.5.x and below
The .prop()
method is not available, so you need to use .attr()
.
$('.myCheckbox').attr('checked', true);
$('.myCheckbox').attr('checked', false);
Note that this is the approach used by jQuery's unit tests prior to version 1.6 and is preferable to using $('.myCheckbox').removeAttr('checked');
since the latter will, if the box was initially checked, change the behaviour of a call to .reset()
on any form that contains it – a subtle but probably unwelcome behaviour change.
For more context, some incomplete discussion of the changes to the handling of the checked
attribute/property in the transition from 1.5.x to 1.6 can be found in the version 1.6 release notes and the Attributes vs. Properties section of the .prop()
documentation.
Best Answer
SWFUpload
http://demo.swfupload.org/v220beta3/simpledemo/index.php
http://swfupload.org/
Javascript and Flash, there's no post-back :) and there's .NET implementations available on the site.