截断时出现HTML错误？

Question

I have the following function:

function truncate($string, $limit, $break=".", $pad="...") { 
  if(strlen($string) <= $limit) return $string; 
    if(false !== ($breakpoint = strpos($string, $break, $limit))) { 
      if($breakpoint < strlen($string) - 1) { 
        $string = substr($string, 0, $breakpoint) . $pad; 
      } 
    } 

    return $string; 
}

If i have the following code:

$html = '<div style="bla: bla;">somet30ext</div> <div id="bla">MORE AND MORE TEXT</div>';
print truncate($html, 30);

It will cut off at somet..... In other words, we end with:

<div style="bla: bla;">somet 

I.e. an unclosed div tag. How do I go about solving this?

Update:

I don't want to truncate only when I get to the . I want something that can automatically add divs. In this case, the output should be:

     <div style="bla: bla;">somet</div>

I.e. It actually added the because it knew it was unclosed? Am I correct in assuming I must use something like html purifier for this?

Answer 1

Don't truncate the $html but rather the real text where it's appropriate. To get hold of the text, you could use php's xml functions (DOM, SimpleXml) or regular expression. Though I'd advice the first.

Example using Dom:

$html = '<div style="bla: bla;">somet30ext</div> <div id="bla">MORE AND MORE TEXT</div>';

$dom = new DomDocument;
$dom->loadHtml($html);

$xpath = new DomXpath($dom);

// example of getting a div with id=bla
$bla = $xpath->query('//div[@id="bla"]')->item(0);
if ($bla instanceof DomNode) {

  // truncate here
  if (strlen($bla->nodeValue) > 10) {
    $bla->nodeValue = substr($bla->nodeValue, 0, 10) . '...';
  }
}

// collect result, this is needed due to dom->loadhtml wrapping the loaded string
// with html/body if not present
$result = '';
foreach ($xpath->query('//body/*') as $childNode) {
  $result .= $dom->saveHtml($childNode);
}

echo $result;