Why did the width collapse in the percentage width child element in an absolutely positioned parent on Internet Explorer 7?
HtmlCssInternet Explorer-7Html Problem Overview
I have an absolutely positioned div
containing several children, one of which is a relatively positioned div
. When I use a percentage-based width
on the child div
, it collapses to 0 width
on IE7, but not on Firefox or Safari.
If I use pixel width
, it works. If the parent is relatively positioned, the percentage width on the child works.
- Is there something I'm missing here?
- Is there an easy fix for this besides the
pixel-based width
on the child? - Is there an area of the CSS specification that covers this?
Html Solutions
Solution 1 - Html
The parent div
needs to have a defined width
, either in pixels or as a percentage. In Internet Explorer 7, the parent div
needs a defined width
for child percentage div
s to work correctly.
Solution 2 - Html
Here is a sample code. I think this is what you are looking for. The following code displays exactly the same in Firefox 3 (mac) and IE7.
#absdiv {
position: absolute;
left: 100px;
top: 100px;
width: 80%;
height: 60%;
background: #999;
}
#pctchild {
width: 60%;
height: 40%;
background: #CCC;
}
#reldiv {
position: relative;
left: 20px;
top: 20px;
height: 25px;
width: 40%;
background: red;
}
<div id="absdiv">
<div id="reldiv"></div>
<div id="pctchild"></div>
</div>
Solution 3 - Html
IE prior to 8 has a temporal aspect to its box model that most notably creates a problem with percentage-based widths. In your case here an absolutely positioned div
by default has no width. Its width will be worked out based on the pixel width of its content and will be calculated after the contents are rendered. So at the point, IE encounters and renders your relatively positioned div
its parent has a width of 0 hence why it itself collapses to 0.
If you would like a more in-depth discussion of this along with lots of working examples, have a gander here.
Solution 4 - Html
> Why doesn’t the percentage width child > in absolutely positioned parent work > in IE7?
Because it's Internet Explorer.
> Is there something I'm missing here?
That is, to raise your co-workers' / clients' awareness that IE is not good.
> Is there an easy fix besides the pixel-based width on the child?
Use em
units as they are more useful when creating liquid layouts as you can use them for padding and margins as well as font sizes. So your white space grows and shrinks proportionally to your text if it is resized (which is really what you need). I don't think percentages give a finer control than ems; there's nothing to stop you specifying in hundredths of ems (0.01 em) and the browser will interpret as it sees fit.
> Is there an area of the CSS specification that covers this?
None, as far as I remember em
's and %'s were intended for font sizes alone back at CSS 1.0.
Solution 5 - Html
I think this has something to do with the way the hasLayout
property is implemented in the older browser.
Have you tried your code in IE8 to see if works in there, too? IE8 has a Debugger (F12) and can also run in IE7 mode.
Solution 6 - Html
The div
needs to have a defined width:
<div id="parent" style="width:230px;">
<div id="child1"></div>
<div id="child2"></div>
</div>
Solution 7 - Html
The parent <div>
tag doesn't have any width specified. Use it for the child <div>
tags, it could be percentage or pixel, but whatever it would be,it should link to its appropriate positions:
<div id="MainDiv" style="width:60%;">
<div id="Div1">
...
</div>
<div id="Div2">
...
</div>
...
</div>