How to sort View results programmatically?

Question

I'm trying to take the results of a view - using the function views_get_view_result() - and sort the array in a way I couldn't do from within the Views interface. So far so good. I've got a $rows variable with all of the stuff I need.

Now... How do I put it back? :) Before I needed this sort, I used views_embed_view(), but I can't do that anymore.

Grateful for any help on this, feels like I'm so close to cracking it!

$important_var = important_function();
$result = views_get_view_result($view, $display, $args);
$result = sorting_function($result, $important_var);

//TODO: Put the result back into the view

Answer 1

The views module provides some hooks for 'external' manipulations, just like Drupal core.

You can implement hook_views_pre_render(&$view) within a custom module and manipulate the result array available in $view->result:

/**
 * Implementation of hook_views_pre_render()
 *
 * @param view $view
 */
function YourModuleName_views_pre_render(&$view) {
  // Check if this is the view and display you want to manipulate
  // NOTE: Adjust/Remove the display check, if you want to manipulate some/all displays of the view
  if ('YourViewName' == $view->name && 'YourDisplayName' == $view->current_display) {
    // EXAMPLE: Just reverse result order
    // TODO: Replace with your desired (re)ordering logic
    $view->result = array_reverse($view->result);
  }
}

The hook is invoked in the middle of the view generation process, after all result data has been assembled, but before the actual output gets rendered, so changes to the result array will be reflected in the views final output.

EDIT: Alternatively, you could process the view 'manually', by copying the behavior of the views_get_view_result() function, but instead of returning the result, you manipulate it and continue to render the view:

function yourModule_get_custom_sorted_view($display_id = NULL) {
  // As the custom sorting probably only works for a specific view,
  // we 'demote' the former $name function parameter of 'views_get_view_result()'
  // and set it within the function:
  $name = 'yourViewName';
  // Prepare a default output in case the view definition can not be found
  // TODO: Decide what to return in that case (using empty string for now)
  $output = '';

  // Then we create the result just as 'views_get_view_result()' would do it:
  $args = func_get_args();
  if (count($args)) {
    array_shift($args); // remove $display_id
  }

  $view = views_get_view($name);
  if (is_object($view)) {
    if (is_array($args)) {
      $view->set_arguments($args);
    }
    if (is_string($display_id)) {
      $view->set_display($display_id);
    }
    else {
      $view->init_display();
    }
    $view->pre_execute();
    $view->execute();
    // 'views_get_view_result()' would just return $view->result here,
    // but we need to go on, reordering the result:
    $important_var = important_function();
    $view->result = sorting_function($result, $important_var);
    // Now we continue the view processing and generate the rendered output
    // NOTE: $view->render will call $view->execute again,
    // but the execute method will detect that it ran already and not redo it.
    $output = $view->render();
    // Clean up after processing
    $view->post_execute();
  }

  return $output;
}

Note: This is a lot of code duplication and thus error prone - I do not recommend this and would rather go with the hook implementation above, trying to find a way to get access to your '$important_var' from within that.

Answer 2

Depending on your sorting logic, you might trying using hook_views_query_alter() to implement your sort directly into the query.

This can be a little tricky though, you may to familiarize yourself with the views_query object.

Here is a real world example where I applied a join rule based on the context of the page, then additionally added sorting rules.

/** 
 * Implementation of hook_views_query_alter(). 
 */ 
function yourmodule_views_query_alter(&$view, &$query) { 
  if ($view->name == 'view_projects' && $view->current_display == 'panel_pane_4') { 
    if (arg(0) == 'node' && is_numeric(arg(1))) { 
      $node = node_load(arg(1)); 
      if ($client_nid = $node->field_ref_client[0]['nid']) { 
        $query->table_queue['node_node_data_field_ref_client']['join']->extra = "field_ref_client_nid = " . $client_nid;
        $query->add_orderby('node', NULL, 'DESC', 'node_node_data_field_ref_client_nid'); 
        $query->add_orderby('node', 'created', 'DESC'); 
      } 
    }
  } 
}

See: http://drupalcontrib.org/api/function/hook_views_query_alter/6