How do I change the delta values using a hook?
You can specify the validation criteria with PHP code in your contextual filter settings:

When the filter value IS in the URL or a default is provided

Specify validation criteria -> PHP Code

if($handler-&gt;argument){
  $view-&gt;display['default']-&gt;handler-&gt;options['pager']['options'] = array(
    'offset' =&gt; 0, 
    'items_per_page' =&gt; $handler-&gt;argument
  );
  return true;
}
else {
  return false;
}


That's it. Now, for every request the delta will be equal with the argument from the URL.
$handler-&gt;argument It's the argument which has been provided by your contextual filter.