Jquery Infinite-Scroll not infinite past page 2 - php

Question

I'm using infinite scroll with dynamic data but can't seem to get past page 2...
When the page initially loads I have an offset in the URL so we start at 0, so,
test2.html?offset=0
this is the code to load the date
$offset = $_GET['offset'];
$data = mysql_query("select * from list limit 30 offset $offset;",$db);
echo '<div id="wall" class="transitions-enabled infinite-scroll clearfix">';
while ($databack33 = mysql_fetch_array($data)){
echo '<div class="block">';
echo '';
echo '</div>';
}
Then to load the next page i use:
<nav id="page-nav">
<? $offset = $offset+30; ?>
</nav>
This works ok for pages one and two but it then tells me no more pages to load although there is more data.
If I look at the page source it is correct test2.html?offset=60
this is the masonry/infinite scroll set up
<script type="text/javascript">
$(function(){
var $container = $('#wall');
$container.imagesLoaded(function(){
$container.masonry({
itemSelector: '.block',
isAnimated: true,
animationOptions: {
duration: 750,
easing: 'linear',
queue: false
}
});
});
$container.infinitescroll({
navSelector : '#page-nav', // selector for the paged navigation
nextSelector : '#page-nav a', // selector for the NEXT link (to page 2)
itemSelector : '.block', // selector for all items you'll retrieve
loading: {
finishedMsg: 'No more pages to load.',
img: 'http://i.imgur.com/6RMhx.gif'
}
},
// trigger Masonry as a callback
function( newElements ) {
// hide new items while they are loading
var $newElems = $( newElements ).css({ opacity: 0 });
// ensure that images load before adding to masonry layout
$newElems.imagesLoaded(function(){
// show elems now they're ready
$newElems.animate({ opacity: 1 });
$container.masonry( 'appended', $newElems, true );
});
}
);
});
</script>

Answer 1

To get infinitescroll working with "offset=" pagination I did the following:
Store the current 'next page' url, and get the offset value.
var nextSelector = '#page-nav a';
var origNextUrl = $(nextSelector).attr('href');
var offsetRegex = /(offset=)([0-9]+)/;
var offset = origNextUrl.match(offsetRegex)[2];
Then in infinitescroll assign a function to the 'path' option which accepts a page number and returns the url used to load the next page.
$container.infinitescroll({
// other options
path: function(pageNum) {
return origNextUrl.replace( offsetRegex, ("$1" + (offset * pageNum)) );
},
//callback
});