[RESOLVED] preg_replace, display x words before/after keyword

coldwerturkey

What preg_replace pattern would I use to display, say, 75 characters before and 75 characters after a keyword mid body in a paragraph?

..75 or so characters keyword another 75 or so character..

nrg_alpha

Well, in this case, I would personally resort to exploding and other string specific functionality. Here is what I came up with:

Example:

$keyword = 'contract';
$str = <<<DATA
SUNRISE, Fla. -- A third-period comeback was the perfect way to cap a great day for Daniel Alfredsson and the Ottawa Senators.
Hours after captain Daniel Alfredsson signed a four-year contract extension, Dany Heatley and Chris Kelly scored to help the Senators beat Florida 2-1.
"It makes a big difference," Alfredsson said. "I'm really going to enjoy dinner tonight, I can tell you that, coming back the way we did."
DATA;

$array = explode($keyword, $str);
if(count($array) > 1 && strlen($array[0]) > 74 && strlen($array[1]) > 74){
   $finalString = substr($array[0], -75) . '<span style=\'color: #FE0606;\'><strong>' . $keyword . '</strong></span>' . substr($array[1], 0, 74);
   echo $finalString;
} else {
   echo 'Error.. not enough characters involved...';
}

Ouput:

Ottawa Senators. Hours after captain Daniel Alfredsson signed a four-year contract extension, Dany Heatley and Chris Kelly scored to help the Senators beat

Of course, here's the crux. Depending on which key word you use, and how long the paragraph, you may end up with more than two arrays from the explode function.. so the question becomes.. which two arrays do you choose?

Case in point... suppose you change the value of $keyword to 'and'.... there are more than two arrays.. so which ones do you use? If the key words are not common and are very specific within a paragraph, the solution should work well.. otherwise, it gets a little hazy...

Cheers,

NRG

nrg_alpha

I suppose you could always also do it this way with preg_match if you absolutely wanted a regex solution:

preg_match('#(.{75}' . $keyword . '.{75})#s', $str, $match);
if(isset($match[1])){
	$match[1] = preg_replace('#(.+?)' . $keyword . '(.+)#s', '$1<span style=\'color: #FE0606;\'><strong>' . $keyword . '</strong></span>$2', $match[1]);
   echo $match[1];
} else {
   echo 'Error.. not enough characters involved...';
}

EDIT - I think I would use this second version instead of the first one, as the first one has some issues with some selected words...

coldwerturkey

thats absolutely perfect. thank you so much.

nrg_alpha

🙂 I did make an edit change in my last post.. note the code change (for more accurate key word highlighting), and the EDIT note at the bottom (just in case you posted while I was editing...

Cheers,

NRG