Determing div layout dimensions php - php

Question

I have three div's which are being filled with dynamic text from a database. The div #container is a fixed height and width where the text inside wraps. The three divs are different font sizes. Any of the three div's could have enough text to exceed the container size. I need to determine if the text exceeds the container size and at which letter in which div it occurs. The extraneous text will then be wrapped in something like <span class=hide">text here</span>
<div id="container">
<div id="first"><?php echo $arr['first'] ?></div>
<div id="mid"><?php echo $arr['mid'] ?></div>
<div id="last"><?php echo $arr['last'] ?></div>
</div>
I'm thinking this is impossible to do in PHP as the styling is done client side. Maybe there is a way to fake it? Though that could get ugly really fast.
I'm trying really hard not to do it in javascript because this calculation will be done about 10 times per page viewed. Please don't tell me it's impossible to do in PHP, there's always a way.
Any ideas?

Answer 1

Just in case you decide that client-side makes more sense for you I put together a fiddle. I realize you want to avoid client-side, but you mentioned this would be happening ten times which honestly is very little these days with how much js speed has increased in browsers. It is also a much simpler problem client side.
http://jsfiddle.net/JSRtk/
Basically you detect if the container is overflown. If so you display a 'read more' button. When clicked it will expand the container to show all text and go away.
$('#container > div').each( function() {
if (checkOverflow(this)) {
console.log('overflow detected in ' + $(this).attr('id'));
$(this).after('<p>Read more...</p>');
}
});
$('p').live('click', function() {
$(this).prev('div').css('height', 'auto');
$(this).hide();
});
function checkOverflow(el)
{
var curOverflow = el.style.overflow;
if ( !curOverflow || curOverflow === "visible" )
el.style.overflow = "hidden";
var isOverflowing = el.clientWidth < el.scrollWidth
|| el.clientHeight < el.scrollHeight;
el.style.overflow = curOverflow;
return isOverflowing;
}

Answer 2

Do you have to wrap it in a span for a purpose (i.e. crawlers/seo)? If not you could either set the CSS on the div with a fixed width to have overflow hidden, alternatively, you could figure out how many characters roughly fit in that width (count them) then use strlen() and substr() like so
<?php
$string = "This is a string thats too long to fit";
if(strlen($string) > 20)
echo substr($string,0,20);
else
echo $string;
?>

Answer 3

There is no way for you to calculate the size of a display element in PHP since it is run on the server and not on the client, and it's the client that renders the HTML.
If you have the same container size every time and the same font and font size and styles and everything, you could probably estimate a number of character and cut it off in PHP at that number of characters using substr. But even then, unless you build a table of character sizes or use a monospaced font, there is no way to reliably do what you want.