Question

I’m attempting to find a value X, which matches the pattern:

<span class="line-item-quantity-raw">X</span>

Once I’ve got the value, I want to trim everything else around it. While I know I could do this with preg_match just to get the value and set the variable, I’m quite curious as to why I can’t get my original method with preg_match to function.

$footer = '<div class="line-item-summary">
  <div class="line-item-quantity">
    <span class="line-item-quantity-raw">1</span>
    <span class="line-item-quantity-label">item</span>
  </div>
  <div class="line-item-total">
    <span class="line-item-total-label">Total:</span>
    <span class="line-item-total-raw">$1,500.00</span>
  </div>
</div>';

$pattern = '/.*<span class="line-item-quantity-raw">(\d+)<\/span>.*/';
$replace = '($1) -';
$footer = preg_replace($pattern, $replace, $footer);

Unfortunately this only seems to strip out the span tags as specified in the $pattern however the extra markup on the edges of the $pattern such as .* is still being kept.

Annoyingly running my code in a test page such as http://www.solmetra.com/scripts/regex/index.php seems to work, just not my code above in php.

Answer 1

This is because . is not matching by default line breaks. To make . span multiple lines, you need to add the modifier s:

$pattern = '/.*<span class="line-item-quantity-raw">(\d+)<\/span>.*/s';

s (PCRE_DOTALL)

If this modifier is set, a dot metacharacter in the pattern matches all characters, including newlines. Without it, newlines are excluded. This modifier is equivalent to Perl’s /s modifier. A negative class such as [^a] always matches a newline character, independent of the setting of this modifier.

http://php.net/manual/en/reference.pcre.pattern.modifiers.php