What is the best way, programmatically, to iterate through a view's results?

Question

Given a view, named 'Children' (with two fields: child_node_id and a birth_order_value) what is the best way, programmatically, to iterate through the views results set given a display_id of 'default' and an argument that contains the parent node id?

Previously, I have used the View in a block using code similar to the following:

if ( arg(0) == 'node' && is_numeric(arg(1)) && ! arg(2)) {
   $node = node_load(arg(1));
   $args = array($node->nid);
   $view = views_get_view('Children');
   print $view->preview('default', $args);
}

However, in another block I want to perform some logic based on the values found in the view. You might be able guess that business logic based on my final requirement: I want the block of code supporting the view ('Children') be called multiple times. As I iterate through the view dataset results, I want to recursively iterate through the children nodes querying for their children.

Answer 1

Playing around with Views a bit I seem to have worked out an approach. However, I'd like to leave my question open to other answers and better solutions.

<?php
if ( arg(0) == 'node' && is_numeric(arg(1)) && ! arg(2) ) {
   $node = node_load(arg(1));
   $args = array($node->nid );
   unset($view);
   $view = views_get_view('Children');
   $view->set_display('default');  
   $view->set_arguments($args);
   $view->set_items_per_page(20);
   $view->execute();
   $newarg = array();
   for ($i=0; $i<sizeof($view->result); $i++) {
      $newarg[$i] = $view->render_field('nid_1', $i);
   }
   for ($i=0; $i<sizeof($newarg); $i++) {
      unset($view);
      $view = views_get_view('Children');
      $view->set_display('default');  
      $view->set_arguments($newarg[$i]);
      $view->set_items_per_page(20);
      $view->execute();
      ....
   }
}
?>

The key to executing the view multiple times was for me to unset($view) when I was done with the result set.

Answer 2

I've gotten good mileage out of the following function. The return value is an array of all the view records. Calling dsm($return_value) will give you a good idea of the structure of your particular view.

function _get_view_data($view_name, $args, $page = NULL, $page_size = 0 ) {
    $view = views_get_view($view_name);
    $view->pager['items_per_page'] = $page_size;
    $view->set_arguments($args);
    if ($page) {
        $view->build($page);
        $view->execute($page);
    }
    else {
        $view->execute();
    }
    return $view->result;
}

Answer 3

Here is a helper function already built in to the Drupal API. (I spent a while flailing around in the Drupal Docs, and eventually found it. It seems many others have also produced solutions that don't use this helper, and also that this helper does one interesting step that other solutions don't... to call pre_render on the $view object before execute).

I can't vouch for whether it works well or not, but at least it's a specific place to call out issues with these approaches.

For D6 http://api.drupal.org/api/views/views.module/function/views_get_view_result/6

And for D7 http://api.drupal.org/api/views/views.module/function/views_get_view_result/7