Views with randomization across multiple pages

i guess no-one has ever had a use-case for paged randomness. it's hard to even imagine how that would work. random is usually used to call out some limited fixed number of items.

While it is possible to do the requested functionality, it would require significant work

An pseudo-random solution could use the following logic:

1) Add a new CCK field of type int, no edit or display

2) Create a cron_hook that inserts random numbers into this field

3) Present the view sorted by this random field

Then everytime cron runs you'll get a new sort order. I'd set the cron to reload once a day, so that the pager works for the majority of the day.

Or if you want some good old hacking fun, read on...

A true session based would require a full query to be done to create the indexing. This would then be stored in the session. Personally, I would create a custom module based block or page callback. View do not handle special sorting fields. (Please correct me if you discover that I'm wrong.)

Using a custom array paginator, you can then generate what pages/users to load. See the code snippet in http://drupal.org/node/211819#comment-847409 for the pager.

The query would be similar to this: (This is how views generate their queries)

SELECT node.nid, node.title AS node_title, node.changed AS node_changed, node_data_field_image.field_image_fid AS node_data_field_image_field_image_fid, node_data_field_image.field_image_title AS node_data_field_image_field_image_title, node_data_field_image.field_image_alt AS node_data_field_image_field_image_alt
FROM node node
LEFT JOIN content_type_site node_data_field_site_category ON node.vid = node_data_field_site_category.vid
LEFT JOIN content_field_image node_data_field_image ON node.vid = node_data_field_image.vid
LEFT JOIN content_type_site node_data_field_visit_website ON node.vid = node_data_field_visit_website.vid
WHERE (
node.status = '1'
)
AND (
node.type
IN (
'site'
)
)
AND (
node_data_field_site_category.field_site_category_value =1
)
ORDER BY FIELD( node.nid, 95, 96, 97, 100, 103) ASC
LIMIT 0 , 5

(EDIT: Or seed the engine to simplify the query. Duh)

Where the values, 95, 96, 97, 100, 103 are the values returned by the pager. Make sure that the limit is the same as the count() of the order fields.

I think that it could be a day or two of solid programming to get this running. Use the Devel module to capture the views SQL statement. And remember that the CCK tables change under certain circumstances, so if a field is changed from single to multi, the SQL will also change.

This was off the main topic but here is a starting point for

1. Random user block
2. Random user page

This uses a simple session based seed for the page, and the block is regenerated on each load.

Play, modify and share :)

random_users.info

; $Id$
name = Random users
description = Some session based random madness
package = Other
version = VERSION

random_users.module

<?php

/**
 * Implementation of hook_help().
 */
function random_users_help($section) {
  switch ($section) {
    case 'admin/help#random_users':
      return t('Generates a block and a paged list of users.');
  }
}

/**
 * Implementation of hook_menu().
 */
function random_users_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array('path' => 'users',
      'title' => t('User list'),
      'callback' => 'random_users_list',
      'access' => user_access('access content'),
      'type' => MENU_SUGGESTED_ITEM);
  }
  return $items; 
}

/**
 * Implementation of hook_block().
 */
function random_users_block($op = 'list', $delta = 0, $edit = array()) {

  if ($op == 'list') {
     $blocks[0]['info'] = t('Random users list');
     return $blocks;
  }
  else if ($op == 'configure' && $delta == 0) {
    $form['random_users_block_number_users'] = array(
      '#type' => 'textfield',
      '#title' => t('Number user to display.'),
      '#default_value' => variable_get('random_users_block_number_users', 10),
    );
    return $form;
  }
  else if ($op == 'save' && $delta == 0) {
    variable_set('random_users_block_number_users', $edit['random_users_block_number_users']);
  }
  else if ($op == 'view') {
    if (user_access('access content')) {
          $result = db_query_range('SELECT uid, name FROM {users} WHERE status != 0 AND access != 0 ORDER BY RAND()', 0, variable_get('random_users_block_number_users', 10));
          while ($account = db_fetch_object($result)) {
            $items[] = $account;
          }
          $output = theme('user_list', $items);

          $block['subject'] = t('Some users');
          $block['content'] = $output;
          return $block;
    }
  }
}

/**
 * 
 */
function random_users_list() {
  if (empty($_SESSION['random_users_list'])) {
    $_SESSION['random_users_list'] = rand(1, 999999);
  }
  $seed = $_SESSION['random_users_list'];
  // Extract the affected users:
  //$query, $limit = 10, $element = 0, $count_query
  $result = pager_query("SELECT u.uid FROM {users} u WHERE u.access != 0 AND u.status != 0 ORDER BY RAND(%d)", 20, 0, NULL, $seed);

  $output = '<div id="users-list">';
  while ($account = db_fetch_object($result)) {
    $account = user_load(array('uid' => $account->uid));
    $output .= theme('user_listing', $account) . '<br class="clear"/>';
  }
  $output .= '</div>';
  $output .= theme('pager', 20, 0);
  return $output;
}

function theme_user_listing($account) {
  return '<div>' . theme('username', $account) . '</div>';
}

?>

This is actually pretty easy, see http://dev.mysql.com/doc/refman/5.0/en/mathematical-functions.html#funct... (and much more sane than the cck rand solution)
I'm currently working on a patch for views 2 which will either add the functionality in the existing random field or I'll release a new module. I'll see if I can backport it easily to views 1.