Question

I’ve noticed that the .end() cannot get back the old set of jquery elements, if I set jQuery elements in find().

According to jquery document http://api.jquery.com/find/ . It should accept jQuery object. Is it a bug? Or something I should know ? Thank you very much.

<section>
<div id="myDiv" style="display:none;">
    This is my DIV ... <span id="p-text"></span>
</div>
</section>

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
<script>
window.onload = function(){

var $m = $('#myDiv');
var $t = $('#p-text');

// this will show myDiv
$m.find('#p-text').text('blabla').end().show();

// this will not show myDiv
$m.find($t).text('blabla2').end().show();
}
</script>

Answer 1

Re-EDIT:

The difference is between $m.find(<string selector>) and $m.find(<jquery object>);

Assumptions

• The end() function return an object called prevObject (this is a not-documented public property of jquery stack), stored in returned jquery stack.
• This property is set, indirectly, in function like find and filter
• The method find behaves differently depending on type of argument (string or jquery Object)

what happens

• if the argument is <String selector> then it store the current jquery object in this prevObject property.
• if the argument is <jquery object> then store the RETURNED stack in this property.

indeed:

$m.find('#p-text') // return a stack with element <span> and prevObject = $m
.text('blabla') // change simply the text
.end() // return the stack stored in prevObject (ie $m)
.show(); // show the current stack (ie $m)

and it works because $m is the element with display:none

in the second case:

$m.find($t) // return a stack with <span> element BUT the prevObject property is the $t element
.text('blabla2') // again change the text
.end() // return the stack stored in prevObject (IE $t now!!)
.show(); // show the current stack (ie $t)

and it does NOT works because the $t element is only a child of hidden element.

Why?

The find method use internally the method jQuery( selector ).filter if the selector is a jquery object. Here the piece of source code

if ( typeof selector !== "string" ) {
    return jQuery( selector ).filter(function() { // <---- here
        for ( i = 0, l = self.length; i < l; i++ ) {
            if ( jQuery.contains( self[ i ], this ) ) {
                return true;
            }
        }
    });
}

This call return a stack with prevObject filled with jQuery( selector ) instead of original stack. In your case the prevObject is the jquery object $t instead of $m.

I think that’s a bug resulted from a objectless use of jquery library (your code has no sense because you should write simply $t.text('blabla2').show())