string to int casting problem?

owad

Hopefully this is a simple casting problem, but I'm utterly stumped...

I am trying to parse the line:

[node:478]

using this code:

$preg = array(
...
    '#\[node:(\d+)]#si'  =>  nid_to_link('\\1'),
...
)

which calls this function:

function nid_to_link($nid) {
   $output = "nid: $nid";
   $output .= " intval: ";
   $output .= intval($nid);
   return $output;
}

The output is:

nid: 478 intval: 0

Anybody know why I am unable to cast nid to an int? I've tried various other methods including casting with (int), (integer), adding 0, etc. Any advice is most appreciated.

laserlight

You have succeeded.

The string '\1' has an integer value of 0, for PHP strings.

basically, conversion from numeric strings to numbers is performed on the numeric portion on the string up to the first non-numeric character.

Since the first character is non-numeric, the string is regarded as non-numeric, and so has a numeric value of 0.

owad

I just realized some of my backslashes got stripeed. The correct line is:

'#\[node:(\d+)]#si'  =>  nid_to_link('\\1'),

Thanks for the help. Apparently '\1' isn't working at all how I expected it to.

strlen($nid) is 2

If I do: substr($nid, 0, 2)
The string "478" is returned.

If I do: substr($nid, 0, 1) or substr($nid, 1, 1)
The strings "\" and "1" are returned, respectively.

I tried tinkering around with setting the substring to start at locations like -1 or 3, but to no avail. Where is "478" actually stored?!?

owad

Ok, if I replace "//1" with "$1", I get the same issue, which makes more sense to me.

I'm not too familiar with php. This almost seems like a pointers issue... If $id contains "$1", how can I get the value stored at $1?

laserlight

Oh yeah.
Use [code] instead of [php] when you're using regex, or the code is likely to have backslashes stripped.

btw, you're just declaring an array.
I presume there is an actual preg_match() or preg_grep() somewhere else?

owad

Yes. The next line is:

$body = preg_replace(array_keys($preg), array_values($preg), $body);

laserlight

I see.
You'll need to implement nid_to_link() as a callback function.

<?php
function nid_to_link($nid) {
	$nid = $nid[1];
	$output = "nid: $nid";
	$output .= " intval: ";
	$output .= intval($nid);
	return $output;
}

$preg = array(
	'#\[node:(\d+)]#si' => nid_to_link('\\1')
	);

$body = "hello [node:478] world";
$body = preg_replace_callback(array_keys($preg), "nid_to_link", $body);
echo $body;
?>

owad

Perfect. Thanks, laserlight!

If you're curious, here's the finished function:

function nid_to_link($nid) {
	$nid = $nid[1];
	$node = node_load(array("nid" => $nid)); 
	$title = $node->title;
	if ($title == "")
		$output = '<b>Error: </b> Node ' . $nid . ' does not exist.';
	else
		$output = '<a href="/node/view/' . $nid . '">' . $title . '</a>';
    return $output;
}

A link to the given node is created, with the node's title as the link's text. This is part of a module for the Drupal CMS.

Thanks again!