Wrapping code in a function prevents it from working - function

Question

I want to wrap my code in a function (and then put it in functions.php) so that I can call it elsewhere but my code fails as soon as I wrap it in a function.
I think this may be a scope issue, do I have to pass the the post number somehow to the function? If I get rid of the function that's wrapped around the query, the code works fine.
I'm guessing that the code is irrelevant really (although I may be wrong) - it's more to do with the fact that it's a loop and a function.
<?php function getGallery2() { ?>
<!-- 1. search for any pages with a custom field of 'test' that have a value of 'yes' -->
<?php query_posts('meta_key=Gallery - Promotion Gallery Photo Link&post_type=page'); ?>
<?php while ( have_posts() ) : the_post(); ?>
<!-- 2. echo the test field -->
<?php $link = get_post_meta($post->ID, 'Gallery - Promotion Gallery Photo Link', true); ?>
<?php $alt = get_post_meta($post->ID, 'Gallery - Promotion Gallery Photo Alt text', true); ?>
<img src="<?php echo $link ?>" alt="<?php echo $alt ?>" />
<?php endwhile;?>
<?php wp_reset_query(); ?>
<?php } ?>
<?php getGallery2(); ?>

Answer 1

You would have it something like this I think (not tested):
<?php function getGallery2() { ?>
$global post;
$link = get_post_meta($post->ID, 'Gallery - Promotion Gallery Photo Link', true); ?>
$alt = get_post_meta($post->ID, 'Gallery - Promotion Gallery Photo Alt text', true); ?>
<img src="<?php echo $link ?>" alt="<?php echo $alt ?>" />
<?php } ?>
Then call the function within any loop on any PHP page. Make sense? i.e. don't loop within the function. I don't understand why you don't just use a php include? i.e.
require('get-gallery.php');
Hope that helps :D

Answer 2

$post is not in the functions scope.
You can add global $post; to the top of the function or you can include it as a parameter like this:
function getGallery2($post){
// code
}
echo getGallery2($post)
Code inside a function can only see variables that were created within the same function or in global scope. Meaning the $post object is undefined.
//
On a slightly off topic note, you have lots of HTML comments within PHP. You could easily tidy things p by making it all PHP.
EDIT:
function getGallery2(){
global $post;
// 1. search for any pages with a custom field of 'test' that have a value of 'yes' -->
query_posts('meta_key=Gallery - Promotion Gallery Photo Link&post_type=page');
while ( have_posts() ) : the_post();
// 2. echo the test field -->
$link = get_post_meta($post->ID, 'Gallery - Promotion Gallery Photo Link', true);
$alt = get_post_meta($post->ID, 'Gallery - Promotion Gallery Photo Alt text', true);
echo '<img src="'.$link.'" alt="echo $alt " />';
endwhile;
wp_reset_query();
}
getGallery2();