slideUp isn't the correct opposit to slideDown

[Simon]

SlideDown make elements visible also if an ancestor has the hidden style (:visible selector).

SlideUp doesn't make an element exlicit invisible if an ancestor has the hidden style (:hidden selector).

E.g. 2 Elements: one visible and another hidden by his parent. The span elements are hidden by default via a css hidden class.

<p style="visible: none;">
  <span class="elements hidden"></span>
<p>
<p>
  <span class="elements hidden"></span>
</p>

1) $('.elements').slideDown(); overwrites the hidden class and make span elements explicit visible. If you call later $('p').show(); both span elements are visible.

2) $('.elements').slideUp(); only hide the second span element in case of the first p is hidden. if you make the first p visible the span element is also visible, but your aim is to make all span.elements explicit invisible. In contrast if you call $('.elements').hide(); all elements are invisible.

I think it's line 6416 in jQuery core-file (but I'm not sure):

if ( prop[p] === "hide" && hidden || prop[p] === "show" && !hidden ) {
return opt.complete.call(this);
}

In case of a hidden ancestor IMHO it would be better to hide the element explicit, like the function hide() do it.

[jitter]

Thanks for taking the time to contribute to the jQuery project by writing a bug report.

As you didn't provide a working live test case and the code you posted is incomplete and partially invalid (style="visible: none;" ??) it's difficult to evaluate if there is any bug at all.

I made this  test case based on what you posted and by guessing what the markup/css looks like. I can't seem to reproduce what you are describing.

Please report back with a valid test case (on  http://jsfiddle.net) which reproduces the issue you are experiencing also consider adding more information (jQuery version, browser version)

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 How to report bugs

[Simon]

Thank you for helping me, it's my first jQuery bug report.

Your example is almost the case that I mean, that is why I'm adopted your code and add only a hide button ( test case). You can comprehend the bug when you follow this steps: 1) click slideDown
2) click show
3) click hide
4) click slideUp
5) click show <-- here you can see the bug. The "b" isn't hidden.

My environment:
jQuery Version 1.4.4,
Firefox 3.6.13 on both Mac OS 10.6 and Windows XP (German Version)
Internet Explorer 8 on Windows XP

[dmethvin]

I think you're advocating that if a parent is hidden, slideUp should still "hide" the child element so that when the parent is ever unhidden the child will still be hidden.

I think the current behavior is a side-effect of the way we determine visibility, which is via a 0 height/width. Not sure if we want to change this, but I can see your point about symmetry.

[john]

Yeah, I don't think that's a change that we're going to make, unfortunately.

[Ariel <asjquery@…>]

I just ran into this exact same issue. Are you certain you won't fix it?

Please reconsider.

I would expect it to display: none; the element if the parent is hidden, but not animate it.

I managed to work around it by adding $(this).hide() in the callback but it seems wrong that it doesn't already do that.