weight.module

<?php

/**
 * Implements hook_permission().
 */
function weight_permission() {
  return array(
    'assign node weight' => array(
      'title' => t('Assign node weights'),
      'description' => t('Allow modification of node weights.'),
    ),
  );
}

/**
 * Implements hook_menu_alter().
 */
function weight_menu_alter(&$items) {
  $enabled = FALSE;
  $settings = _weight_get_settings();

  // Check to see if  any content types are weight enabled.
  foreach ($settings as $setting) {
    if ($setting['enabled']) {
      $enabled = TRUE;
      break;
    }
  }

  // If we have an enabled type and the option to override the front page is set,
  // change the callback for the frontpage.
  if ($enabled && variable_get('weight_frontpage', 1)) {
    $items['node']['page callback'] = 'weight_page_default';
  }
}

/**
 * Page callback for default frontpage.
 *
 * Mostly copied from node_page_default().
 */
function weight_page_default() {
  $select = db_select('node', 'n');
  $select->join('weight_weights', 'w', 'w.entity_id = n.nid');
  $select->fields('n', array('nid'))
    ->condition('n.promote', 1)
    ->condition('n.status', 1)
    ->orderBy('n.sticky', 'DESC')
    ->orderBy('w.weight', 'ASC')
    ->orderBy('n.created', 'DESC')
    ->extend('PagerDefault')
    ->limit(variable_get('default_nodes_main', 10))
    ->addTag('node_access');
  $nids = $select->execute()->fetchCol();

  if (!empty($nids)) {
    $nodes = node_load_multiple($nids);
    $build = node_view_multiple($nodes);

    // 'rss.xml' is a path, not a file, registered in node_menu().
    drupal_add_feed('rss.xml', variable_get('site_name', 'Drupal') . ' ' . t('RSS'));
    $build['pager'] = array(
      '#theme' => 'pager',
      '#weight' => 5,
    );
    drupal_set_title('');
  }
  else {
    drupal_set_title(t('Welcome to @site-name', array('@site-name' => variable_get('site_name', 'Drupal'))), PASS_THROUGH);

    $default_message = '<p>' . t('No front page content has been created yet.') . '</p>';

    $default_links = array();
    if (_node_add_access()) {
      $default_links[] = l(t('Add new content'), 'node/add');
    }
    if (!empty($default_links)) {
      $default_message .= theme('item_list', array('items' => $default_links));
    }

    $build['default_message'] = array(
      '#markup' => $default_message,
      '#prefix' => '<div id="first-time">',
      '#suffix' => '</div>',
    );
  }

  return $build;
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function weight_form_system_site_information_settings_alter(&$form, &$form_state) {
  $form['front_page']['weight_frontpage'] = array(
    '#type' => 'checkbox',
    '#title' => t('Use weighted front page?'),
    '#description' => t('Selecting this option will emulate the default front page,
      but the nodes will be sorted by weight. Only nodes of content types that are
      weight enabled will be shown.'),
    '#return_value' => 1,
    '#default_value' => variable_get('weight_frontpage', 1),
    '#weight' => 5,
  );

  $form['front_page']['site_frontpage']['#weight'] = 10;
  $form['front_page']['site_frontpage']['#states'] = array(
    'visible' => array(
      ':input[name="weight_frontpage"]' => array('checked' => FALSE),
    ),
  );
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function weight_form_node_admin_content_alter(&$form, &$form_state) {
  if (user_access('assign node weight')) {
    $weight_types = _weight_get_types();

    if (!empty($form['admin']['nodes']['#options'])) {
      $nodes = $form['admin']['nodes']['#options'];
    }
    elseif (!empty($form['admin']['nodes']['#rows'])) {
      $nodes = $form['admin']['nodes']['#rows'];
    }
    else {
      $nodes = array();
    }

    foreach ($nodes as $nid => $node) {
      $node = node_load($nid);
      if (in_array($node->type, $weight_types)) {
        $settings = _weight_get_settings($node->type);
        $options = _weight_get_options($settings['range']);
        $form['weight'][$nid] = array(
          '#type' => 'select',
          '#options' => $options,
          '#default_value' => isset($node->weight_weight) ? $node->weight_weight : $settings['default'],
          '#ajax' => array(
            'callback' => '_weight_set_ajax',
          ),
        );
      }
      else {
        $form['weight'][$nid] = array(
          '#value' => '',
        );
      }
    }

    $form['#after_build'][] = 'weight_node_admin';
  }
}

function _weight_set_ajax($form, $form_state) {
  $nid = $form_state['input']['_triggering_element_name'];
  $weight = $form_state['values'][$nid];
  $node = node_load($nid);
  $node->weight_weight = $weight;
  _weight_set_weight($node);
}

/**
 * After build callback for node_admin_content form.
 */
function weight_node_admin($form_element, &$form_state) {
  $form_element['admin']['nodes']['#header']['weight']['data'] = t('Weight');

  if (!empty($form_element['admin']['nodes']['#options'])) {
    foreach ($form_element['admin']['nodes']['#options'] as $nid => $node) {
      $form_element['admin']['nodes']['#options'][$nid]['weight']['data'] = $form_element['weight'][$nid];
    }
  }
  elseif (!empty($form_element['admin']['nodes']['#rows'])) {
    foreach ($form_element['admin']['nodes']['#rows'] as $nid => $node) {
      $form_element['admin']['nodes']['#rows'][$nid]['weight']['data'] = $form_element['weight'][$nid];
    }
  }
  unset($form_element['weight']);

  return $form_element;
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function weight_form_node_type_form_alter(&$form, &$form_state) {
  $settings = _weight_get_settings($form['#node_type']->type);
  if (isset($settings['range'])) {
    $range = $settings['range'];
  }
  else {
    $range = 20;
  }

  $form['weight_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Weight Settings'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
    '#group' => 'additional_settings',
    '#access' => user_access('assign node weight'),
  );

  $form['weight_settings']['weight_enabled'] = array(
    '#type' => 'radios',
    '#title' => t('Enable'),
    '#description' => t('Enable weight for this content type?'),
    '#options' => array(t('No'), t('Yes')),
    '#default_value' => isset($settings['enabled']) ? $settings['enabled'] : 0,
  );

  $form['weight_settings']['weight_range'] = array(
    '#type' => 'radios',
    '#title' => t('Weight Range'),
    '#description' => t('This will be the range available when selecting a weight.'),
    '#options' => array(
      10 => '&plusmn; 10',
      20 => '&plusmn; 20',
      50 => '&plusmn; 50',
      100 => '&plusmn; 100',
    ),
    '#default_value' => $range,
  );

  $form['weight_settings']['weight_menu'] = array(
    '#type' => 'radios',
    '#title' => t('Use Menu Weight'),
    '#description' => t('Use the menu weight of the node, if it has one.'),
    '#options' => array(t('No'), t('Yes')),
    '#default_value' => isset($settings['menu_weight']) ? $settings['menu_weight'] : 0,
  );

  $form['weight_settings']['weight_default'] = array(
    '#type' => 'select',
    '#title' => t('Default Weight'),
    '#description' => t('This weight will be applied to nodes if none is selected.'),
    '#options' => _weight_get_options($range),
    '#default_value' => isset($settings['default']) ? $settings['default'] : 0,
  );

  $form['weight_settings']['sync_translations'] = array(
    '#type' => 'radios',
    '#title' => t('Sync translations'),
    '#description' => t('When changing the weight of a node, also update it\'s translations.'),
    '#options' => array(t('No'), t('Yes')),
    '#default_value' => isset($settings['sync_translations']) ? $settings['sync_translations'] : 0,
  );

  $form['additional_settings']['#attached']['js'][] = drupal_get_path('module', 'weight') . '/weight.js';
  $form['#submit'][] = 'weight_node_type_form_submit';
}

/**
 * Additional submit function for node_type_form().
 */
function weight_node_type_form_submit($form, &$form_state) {
  $values = $form_state['values'];

  $exists = db_query('SELECT 1 FROM {weight_settings} WHERE type=:type',
    array(':type' => $values['type']))->fetchField();

  if ($exists) {
    db_update('weight_settings')
      ->fields(array(
        'weight_enabled' => $values['weight_enabled'],
        'weight_range' => $values['weight_range'],
        'menu_weight' => $values['weight_menu'],
        'weight_default' => $values['weight_default'],
        'sync_translations' => $values['sync_translations'],
      ))
      ->condition('type', $values['type'])
      ->execute();
  }
  else {
    $query = db_insert('weight_settings')
      ->fields(array(
        'type' => $values['type'],
        'weight_enabled' => $values['weight_enabled'],
        'weight_range' => $values['weight_range'],
        'menu_weight' => $values['weight_menu'],
        'weight_default' => $values['weight_default'],
        'sync_translations' => $values['sync_translations'],
      ))
      ->execute();
  }

  if (!$exists) {
    $default = $values['weight_menu'] ? 'menu' : $values['weight_default'];
    _weight_set_defaults($default, $values['type']);
  }
}

/**
 * Implements hook_form_BASE_FORM_ID_alter().
 */
function weight_form_views_form_alter(&$form, &$form_state, $form_id) {
  $view = $form_state['build_info']['args'][0];

  // Check for a weight field and an empty view.
  if (array_key_exists('weight', $view->field) && empty($view->result)) {
    // No need for buttons on an empty form.
    unset($form['actions']);
  }
}

/**
 * Implements hook_field_attach_form().
 */
function weight_field_attach_form($entity_type, $entity, &$form, &$form_state, $langcode) {
  if ($entity_type == 'node') {
    $settings  = _weight_get_settings($entity->type);
    if (isset($settings['enabled']) && $settings['enabled']) {
      $form['weight'] = array(
        '#type' => 'fieldset',
        '#title' => t('Weight'),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
        '#group' => 'additional_settings',
        '#access' => user_access('assign node weight'),
        '#attached' => array('js' => array(drupal_get_path('module', 'weight') . '/weight.js')),
      );

      $form['weight']['weight_weight'] = array(
        '#type' => 'select',
        '#title' => t('Weight'),
        '#options' => _weight_get_options($settings['range']),
        '#default_value' => isset($entity->weight_weight) ? $entity->weight_weight : $settings['default'],
      );
    }
  }
}

/**
 * Implements hook_node_load().
 */
function weight_node_load($nodes, $type) {
  foreach ($nodes as $node) {
    $node->weight_weight = _weight_get_weight($node);
  }
}

/**
 * Implements hook_node_insert().
 */
function weight_node_insert($node) {
  if (isset($node->weight_weight) && is_numeric($node->weight_weight)) {
    _weight_set_weight($node);
  }
}

/**
 * Implements hook_node_update().
 */
function weight_node_update($node) {
  if (isset($node->weight_weight) && is_numeric($node->weight_weight)) {
    _weight_set_weight($node);
  }
}

/**
 * Implements hook_views_api().
 */
function weight_views_api() {
  return array(
    'api' => 3,
    'path' => drupal_get_path('module', 'weight') . '/views',
  );
}

/**
 * Submit handler for Views Weight form.
 */
function weight_views_submit($form, &$form_state) {
  $values = $form_state['values'];

  $nodes = entity_load('node', $values['nids']);

  foreach ($values['nids'] as $key => $nid) {
    $node = $nodes[$nid];
    $node->weight_weight = $values['weight'][$key][$nid];
    _weight_set_weight($node);
  }

  drupal_set_message(t('Weights saved successfully.'));
}

/**
 * Implementes hook_preprocess_views_view_table().
 */
function weight_preprocess_views_view_table(&$variables) {
  // If there isn't a Weight field or the user doesn't have access to it, don't do anything.
  if (!array_key_exists('weight', $variables['fields']) || !user_access('assign node weight')) {
    return;
  }

  // Add the tabledrag attributes.
  $vars['classes_array'][] = 'draggable';
  foreach ($variables['rows'] as $key => $row) {
    $variables['row_classes'][$key][] = 'draggable';
  }
  $variables['attributes_array']['id'] = 'weight-table';

  drupal_add_tabledrag('weight-table', 'order', 'sibling', 'weight-weight');
}

/**
 * Implements hook_apachesolr_index_document_build_node().
 */
function weight_apachesolr_index_document_build_node(ApacheSolrDocument $document, $node, $env_id) {
  $document->is_weight = (int) $node->weight_weight;
}

/**
 * Implements hook_apachesolr_query_prepare().
 */
function weight_apachesolr_query_prepare($query) {
  // Add a sort on the weight.
  $query->setAvailableSort('is_weight', array(
    'title' => t('Weight'),
    'default' => 'asc',
  ));
}

/**
 * Set the weight of a node.
 */
function _weight_set_weight($node) {
  if (module_exists('translation') && $node->nid != $node->tnid) {
    $settings = _weight_get_settings($node->type);
    if ($settings['sync_translations']) {
      $node->weight_weight = _weight_get_weight($node->tnid);
    }
  }

  db_merge('weight_weights')
    ->key(array('entity_id' => $node->nid))
    ->fields(array(
      'entity_id' => $node->nid,
      'entity_type' => 'node',
      'weight' => $node->weight_weight,
    ))
    ->updateFields(array(
      'weight' => $node->weight_weight,
    ))
    ->execute();
}

/**
 * Get the weight of a node.
 */
function _weight_get_weight($node) {
  if (is_numeric($node)) {
    $nid = $node;
  }
  elseif (module_exists('translation') && $node->nid != $node->tnid) {
    $settings = _weight_get_settings($node->type);
    if ($settings['sync_translations']) {
      $nid = $node->tnid;
    }
    else {
      $nid = $node->nid;
    }
  }
  else {
    $nid = $node->nid;
  }
  $weight = db_query("SELECT weight FROM {weight_weights} WHERE entity_id=:id AND entity_type=:type",
    array(':id' => $nid, ':type' => 'node'))->fetchField();

  return $weight;
}

/**
 * Get weight settings for a content type.
 */
function _weight_get_settings($type = NULL) {
  $settings = array();
  $query = 'SELECT * FROM {weight_settings}';
  if ($type) {
    $query .= ' WHERE type=:type';
    $result = db_query($query, array(':type' => $type));
    foreach ($result as $row) {
      $settings = array(
        'enabled' => $row->weight_enabled,
        'range' => $row->weight_range,
        'menu_weight' => $row->menu_weight,
        'default' => $row->weight_default,
        'sync_translations' => $row->sync_translations,
      );
    }
  }
  else {
    $result = db_query($query);
    foreach ($result as $row) {
      $settings[$row->type] = array(
        'enabled' => $row->weight_enabled,
        'range' => $row->weight_range,
        'menu_weight' => $row->menu_weight,
        'default' => $row->weight_default,
        'sync_translations' => $row->sync_translations,
      );
    }
  }

  return $settings;
}

/**
 * Get content types that are weight enabled.
 */
function _weight_get_types() {
  $types = array();
  $result = db_query('SELECT type FROM {weight_settings} WHERE weight_enabled=1');
  foreach ($result as $row) {
    $types[] = $row->type;
  }

  return $types;
}

/**
 * Get an array of options to for selecting a weight.
 */
function _weight_get_options($range) {
  $max = $range;
  $min = $max * -1;
  $options = array();

  for ($i = $min; $i <= $max; $i++) {
    $options[$i] = $i;
  }

  return $options;
}

/**
 * Set nodes to the default weight.
 */
function _weight_set_defaults($default, $type) {
  // Get the nodes to work with.
  $select = db_select('node', 'n');
  $select->fields('n', array('nid'))
    ->condition('type', $type);
  $results = $select->execute();

  foreach ($results as $result) {
    if ($default == 'menu') {
      // Get the menu weight fot this node.
      $weight = db_select('menu_links', 'ml');
      $weight->fields('ml', array('weight'))
        ->condition('link_path', 'node/' . $result->nid);
      $weight = $weight->execute()->fetchField();
      // If there is no menu item, set the weight to 0.
      if (!$weight) {
        $weight = 0;
      }
    }
    else {
      // Get the weight for this node.
      $weight = db_select('weight_weights', 'w');
      $weight->fields('w', array('weight'))
        ->condition('entity_id', $result->nid);
      $weight = $weight->execute()->fetchField();
      // If there is no weight, set the weight to the default.
      if (!$weight) {
        $weight = $default;
      }
    }

    db_merge('weight_weights')
      ->key(array('entity_id' => $result->nid))
      ->fields(array(
        'entity_id' => $result->nid,
        'entity_type' => 'node',
        'weight' => $weight,
      ))
      ->updateFields(array(
        'weight' => $weight,
      ))
      ->execute();
  }
}