javascript - How can I mimic text-overflow: ellipsis in Firefox?

Question

I have some dynamic text contained in a div that is set to whatever a user enters in a textbox field. If the text doesn't fit in the div, right now it just gets cut off at the edge and all the text that extends past the border is not visible. I would like to truncate the text so that it fits inside the box and has an ellipsis (...) appended on the end. For example:

|----div width------|
 Here is some sample text that is too long.
 Here is some sam...

Obviously in the example it's easy because the code tag uses a fixed-width font so it's as simple as counting characters. I have a variable-width font so if they enter "WWWWWWWWWWW" it will fill up in much fewer characters than "................" would.

What's the best way to do this? I found a potential solution for simply finding the actual pixel width of the text here: http://www.codingforums.com/archive/index.php/t-100367.html

But even with a method like that, it's a bit awkward to implement the ellipsis. So if it's 20 characters and I find that it doesn't fit, I would have to truncate to 19, add the ellipsis, and then check if it fits again. Then truncate to 18 (plus the ellipsis) and try again. And again. And again...until it fit. Is there a better way?

EDIT: I have decided based on the answers that my original approach is best, except I have tried to improve on the solution in the link above by not creating a separate td element simply for measuring, which feels like a hack.

Here is my code:

<div id="tab" class="tab">
    <div id="tabTitle" class="tabTitle">
        <div class="line1">user-supplied text will be put here</div>
        <div class="line2">more user-supplied text will be put here</div>
    </div>
</div>

And styles:

.tab {
padding: 10px 5px 0px 10px;
margin-right: 1px;
float: left;
width: 136px;
height: 49px;
background-image: url(../images/example.gif);
background-position: left top;
background-repeat: no-repeat;
}    

.tab .tabTitle {
    height: 30px;
width: 122px;
    overflow: hidden;
    text-overflow: ellipsis;
font-size: 12px;
font-weight: bold;
color: #8B8B8B;
}

.tab .tabTitle .line1, .tab .tabTitle .line2 {
    display:inline;
    width:auto;
}

and the javascript that trims and adds the ellipsis:

function addOverflowEllipsis( containerElement, maxWidth )
{
    var contents = containerElement.innerHTML;
    var pixelWidth = containerElement.offsetWidth;
    if(pixelWidth > maxWidth)
    {
        contents = contents + "…"; // ellipsis character, not "..." but "…"
    }
    while(pixelWidth > maxWidth)
    {
        contents = contents.substring(0,(contents.length - 2)) + "…";
        containerElement.innerHTML = contents;
        pixelWidth = containerElement.offsetWidth;
    }
}

The "line1" and "line2" divs get passed to the function. It works in the case of a single word input like "WWWWWWWWWWWWWWWWW" but does not work a multi-word input "WWWWW WWWWW WWWWW" because it just adds line breaks and measures the text as being the width of "WWWWW".

Is there a way I can fix this without resorting to copying the text into a hidden measuring element? Some way to set the style of the line divs so that they don't wrap text?

Answer 1

Some way to set the style of the line divs so that they don't wrap text?

There you have the white-space: nowrap for. Yes, this works in ancient browsers as well.