flippy.module

<?php

/**
 * @file
 * Allows administrators to add previous/next pagers to any node type.
 */

/**
 * Implements hook_theme()
 */
function flippy_theme() {
  return array(
    'flippy' => array(
      'arguments' => array(
        'list' => array(),
      ),
      'template' => 'flippy',
    ),
  );
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function flippy_form_node_type_form_alter(&$form, $form_state) {
  $form['flippy'] = array(
    '#type' => 'fieldset',
    '#title' => t('Flippy settings'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );

  $form['flippy']['flippy'] = array(
    '#type' => 'checkbox',
    '#title' => t('Build a pager for this content type'),
    '#default_value' => isset($form['flippy']['flippy']) ?
        $form['flippy']['flippy'] :
        variable_get('flippy_' . $form['#node_type']->type, FALSE),
  );

  $form['flippy']['flippy_label_type'] = array(
    '#type' => 'select',
    '#title' => t('Pager label type'),
    '#options' => array(
      0 => t('Custom text'),
      1 => t('Node title'),
      2 => t('Node ID'),
    ),
    '#default_value' => isset($form['flippy']['flippy_label_type']) ?
        $form['flippy']['flippy_label_type'] :
        variable_get('flippy_label_type_' . $form['#node_type']->type, 0),
    '#description' => t('Select label type to display'),
  );

  $form['flippy']['flippy_prev_label'] = array(
    '#type' => 'textfield',
    '#title' => t('Label for "Previous" link'),
    '#size' => 32,
    '#default_value' => isset($form['flippy']['flippy_prev_label']) ?
        $form['flippy']['flippy_prev_label'] :
        variable_get('flippy_prev_label_' . $form['#node_type']->type, 'Previous'),
  );

  $form['flippy']['flippy_next_label'] = array(
    '#type' => 'textfield',
    '#title' => t('Label for "Next" link'),
    '#size' => 32,
    '#default_value' => isset($form['flippy']['flippy_next_label']) ?
        $form['flippy']['flippy_next_label'] :
        variable_get('flippy_next_label_' . $form['#node_type']->type, 'Next'),
  );

  $form['flippy']['flippy_firstlast'] = array(
    '#type' => 'checkbox',
    '#title' => t('Show first/last links'),
    '#default_value' => isset($form['flippy']['flippy_firstlast']) ?
        $form['flippy']['flippy_firstlast'] :
        variable_get('flippy_firstlast_' . $form['#node_type']->type, FALSE),
  );

  $form['flippy']['flippy_first_label'] = array(
    '#type' => 'textfield',
    '#title' => t('Label for "First" link'),
    '#size' => 32,
    '#default_value' => isset($form['flippy']['flippy_first_label']) ?
        $form['flippy']['flippy_first_label'] :
        variable_get('flippy_first_label_' . $form['#node_type']->type, 'First'),
  );

  $form['flippy']['flippy_last_label'] = array(
    '#type' => 'textfield',
    '#title' => t('Label for "Last" link'),
    '#size' => 32,
    '#default_value' => isset($form['flippy']['flippy_last_label']) ?
        $form['flippy']['flippy_last_label'] :
        variable_get('flippy_last_label_' . $form['#node_type']->type, 'Last'),
  );
}

/**
 * Implements hook_content_extra_fields.
 */
function flippy_content_extra_fields($type_name) {
  $type = node_get_types('type', $type_name);
  $extra = array();

  if (variable_get('flippy_'. $type_name, NULL)) {
    $extra['flippy_pager'] = array(
      'label' => t('Pager'),
      'description' => t('Flippy module content pager'),
      'weight' => variable_get('flippy_wt_'. $type_name, 0),
    );
  }

  return $extra;
}

/**
 * Implements hook_nodeapi().
 */
function flippy_nodeapi(&$node, $op) {
  if ($op === 'view' && $node->build_mode === NODE_BUILD_NORMAL) {
    if (variable_get('flippy_'. $node->type, NULL)) {
      $node->content['flippy_pager'] = array(
        '#value' => theme('flippy', flippy_build_list($node)),
      );
    }
  }
}

/**
 *  Function that builds the list of nodes
 */
function flippy_build_list($node) {
  static $master_list;

  if (!isset($master_list)) {
    $master_list = array();
  }

  if (!isset($master_list[$node->nid])) {
    $q = array();
    $list = array();
    // Create a starting-point query object
    $sql = "SELECT nid, title FROM {node}
        WHERE status = 1 AND type = '%s' AND nid != '%d'";
    $q = array(
      'first' => "\nAND created <= '%d' ORDER BY created ASC",
      'prev'  => "\nAND created <= '%d' ORDER BY created DESC",
      'next'  => "\nAND created >= '%d' ORDER BY created ASC",
      'last'  => "\nAND created >= '%d' ORDER BY created DESC",
    );
    foreach ($q as $key => $query) {
      $query = $sql . $query . "\n LIMIT 1";
      $list[$key] = db_fetch_array(db_query($query, $node->type, $node->nid,
          $node->created));
    }
    $list['current'] = array(
      'nid' => $node->nid,
      'title' => $node->title,
    );
    $master_list[$node->nid] = $list;
  }

  return $master_list[$node->nid];
}

/**
 * Implements template_preprocess_hook()
 *
 * @see flippy.tpl.php
 *
 * @ingroup themeable
 */
function template_preprocess_flippy(&$vars) {
  $node = menu_get_object();
  $nav = $vars['list'];
  drupal_add_css(drupal_get_path('module', 'flippy') . '/flippy.css');

  // for getting node type
  if ($node) {
    $vars['node'] = $node;
  }

  $label_type = variable_get('flippy_label_type_' . $vars['node']->type, NULL);

  if ($nav) {
    if (variable_get('flippy_firstlast_'. $vars['node']->type, NULL)) {
      $vars['first_link'] = empty($nav['first']) ? '' : l('« ' . t(variable_get('flippy_first_label_' . $vars['node']->type, NULL)), 'node/' . $nav['first']['nid']);
      $vars['last_link'] = empty($nav['last']) ? '' : l(t(variable_get('flippy_last_label_' . $vars['node']->type, NULL)) . ' »', 'node/' . $nav['last']['nid']);
    }
    switch ($label_type) {
      case '0':
        $vars['previous_link'] = empty($nav['prev']) ? '' : l('‹ ' . t(variable_get('flippy_prev_label_' . $vars['node']->type, NULL)), 'node/' . $nav['prev']['nid']);
        $vars['next_link'] = empty($nav['next']) ? '' : l(t(variable_get('flippy_next_label_' . $vars['node']->type, NULL)) . ' ›', 'node/' . $nav['next']['nid']);
        break;
      case '1':
        $vars['previous_link'] = empty($nav['prev']) ? '' : l('‹ ' . t($nav['prev']['title']), 'node/' . $nav['prev']['nid']);
        $vars['next_link'] = empty($nav['next']) ? '' : l(t($nav['next']['title']) . ' ›', 'node/' . $nav['next']['nid']);
        break;
      case '2':
        $vars['previous_link'] = empty($nav['prev']) ? '' : l('‹ ' . t($nav['prev']['nid']), 'node/' . $nav['prev']['nid']);
        $vars['next_link'] = empty($nav['next']) ? '' : l(t($nav['next']['nid']) . ' ›', 'node/' . $nav['next']['nid']);
        break;
    }
  }

  $vars = array_merge($vars, $vars['list']);
  unset($vars['list']);
  unset($vars['node']);
}