How to properly submit a dynamically created form

问题:

HTML:

<button class="search" name="search">search</button>

Javascript:

$('button.search').live('click', function(event) {
    var newForm = jQuery('<form>', {
        'action': 'http://www.google.com/search',
        'target': '_top'
    }).append(jQuery('<input>', {
        'name': 'q',
        'value': 'stack overflow',
        'type': 'hidden'
    }));
    newForm.submit();
});

Fiddle: http://jsfiddle.net/YqGLH/90/

Expected behavior: when clicking on the search button, page should forward to google search. Works as expected in latest Chrome, Safari and Opera.

Does not work in latest FF and IE9. Clicking the button silently fails, no error messages, no forwarding happens.

What am I missing here?

回答1:

I don't have a reference to any particular specification to support the why, but I believe it will work if you append the new form to the page:

$('button.search').live('click', function(event) {
    jQuery('<form>', {
        'action': 'http://www.google.com/search',
        'target': '_top'
    }).append(jQuery('<input>', {
        'name': 'q',
        'value': 'stack overflow',
        'type': 'hidden'
    })).appendTo('body')
    .submit();
});

Note also that it would be a good idea not to keep using .live() in any new code, given that it has been removed from the latest version of jQuery. Instead use:

$(document).on('click', 'button.search', function() {    // in jQuery v 1.7+   
// or
$(document).delegate('button.search', 'click', function() {    // in jQuery v 1.4.3+

(Ideally specifying a parent element closer to the button rather than document.)

回答2:

It's also worth mentioning that you must add the form to the body element, not the document. Chrome is forgiving and will work when the form is just added to the document element, but IE and Firefox will need you to add it to the body element specifically.