Reading attribute values from HTML

Question

I have HTML stored in a string. The markup contains form input fields called initval and endval which are the value attribute values I need. How can I get them from this string markup?

<form id="compute">
   <input type="hidden" name="initval" value="tal:00far" />
   <input type="hidden" name="endval" value="utl:80er" />
</form>

Answer 1

Presuming that the structure is very reliably like that, try the following:

$htmlCode = "...";
$matches = array();

if (preg_match_all('/name="(initval|endval)"\s+value="([^"]+)"/', $htmlCode, $matches)) {
    $formValues = array_combine($matches[1], $matches[2]);
} else {
   // error
}

This assumes only whitespace between the name and value attributes, you'll need to make a small change if it differs. preg_match_all() returns an array with the whole regexp match at [0], and then the individual group matches in their corresponding locations [1] & [2], the array combine takes one as keys, one as values and puts it together so you have an associative lookup to get your results.