say I have something like
<body><div id="a"><div id="b">some content</div></div>more content<body>
and I don't know how much height "some content" is going to be. But I have #b styled to position: absolute and #a styled to position: relative so #b's position is relative the the top left corner of #a. Is there some way I can make #a expand to contain #b some that "more content" gets pushed after?
thanks
No. I think you need to describe your original task and people will help you.
that is a problem that is usually solved by including an element that has a "clear: both" style before the more content
<body><div id="a"><div id="b">some content</div></div><div style="clear:both;"></div>more content<body>
EDIT Actually, without a full context it's hard to give a full answer. You should also try including such a "clear: both;" element at the end of div#a like so:
<body><div id="a"><div id="b">some content</div><div style="clear:both;"></div></div><div style="clear:both;"></div>more content<body>
No. Absolute positioning removes elements from document flow. Their parent and sibling tags have no way of knowing that they are overlapping an absolutely positioned element or not.
It sounds like position relative for #b might be a better solution.
As #b is the first element in #a it woudl naturally appear in the top left corner of #a, so position relative will position relative to the same point as position absolute.
Also, say you want to push #b down by 30px, then you set
#b{position:relative;top:30px;margin-bottom:30px;}
Content will clear the bottom of #b because position:relative leaves a block in the content flow equal to the height of #b + 30px;
Your example is flawed as there is no actual need to have pos:abs on div#b as by default that element would be set at the top/left of div#a.
Using css position will take its applied element outside of the normal markup flow, even if you was to use pos:rel on div#b it would only increase the height of div#a it would not take into consideration any positioning you may have also applied to it.
There is a way you could achieve what you are after, but that would rely on using JavaScript.