Help on preg_replace_callback()

[grethe]

Hi i need help on the function preg_replace_callback(). I always get this error:

 

Warning: preg_replace_callback() [function.preg-replace-callback]: Requires argument 2, 'make_br', to be a valid callback

 

Here is my code:

$text = preg_replace_callback('/(\<p\>)(.+)(\<\/p\>)/sU', 'make_br', $text);
function make_br($matches) {
  $matches['2'] = trim($matches['2']);
  $matches['2'] = preg_replace('/\n/', "<br/>\n", $matches['2']);
  return $matches['2'];
}

 

What am i doing wrong?

[effigy]

I'm not having any trouble with it. What version of PHP are you using? Does it work if you isolate it from surrounding code?

[grethe]

Yes you're right it works fine if i isolate it. Thanks.

I've also figured out how to make i work, but there's something in PHP i don't understand then. Can't a function be created anywhere - like in a function and stille work everywhere?

 

This works:

<?php

$text = "123";

echo interpret($text);

function interpret($text) {
  $text = preg_replace_callback('/(\<p\>)(.+)(\<\/p\>)/sU', 'make_br', $text);
  function make_br($matches) {
    $matches['2'] = trim($matches['2']);
    $matches['2'] = preg_replace('/\n/', "<br/>\n", $matches['2']);
    return $matches['2'];
  }

  return $text;
}

?>

 

This doesn't work:

<?php

$text = "123";

echo interpret($text);

function interpret($text) {
  $text = preg_replace_callback('/(\<p\>)(.+)(\<\/p\>)/sU', 'make_br', $text);

  return $text;
}

function make_br($matches) {
  $matches['2'] = trim($matches['2']);
  $matches['2'] = preg_replace('/\n/', "<br/>\n", $matches['2']);
  return $matches['2'];
}

?>

[Wildbug]

It was the first one that didn't work for me.  The second one did.  However, the first one did work when I moved the inner function definintion above the preg_replace_callback that called it.  PHP functions are supposed to be able to be referenced before their definition but maybe that doesn't apply to functions defined within functions.

[grethe]

Whoops.. yes you are right. I mixed them. Hmm.. but still that explanation i think is weird, why shouldn't they work like everywhere else. But maybe you are right. Does annyone know why the function behaves like this?

[Wildbug]

The inner function isn't defined until the outer function is executed.

 

Also see:  http://us.php.net/manual/en/language.functions.php#21149

[grethe]

Thanks a lot..