path_redirect.module

<?php

// The default HTTP status code for redirects is "moved permanently"
define('PATH_REDIRECT_DEFAULT_TYPE', 301);

if (module_exists('workflow_ng')) {
  include_once(drupal_get_path('module', 'path_redirect') .'/path_redirect_workflow.inc');
}

/**
 * Implementation of hook_help
 */
function path_redirect_help($path) {
  switch ($path) {
    case 'admin/build/path-redirect':
      return '<p>'. t('Here you can set up URL redirecting for this site. Any existing or non-existing path within this site can redirect to any internal or external URL.') .'</p>';
    case 'admin/build/path-redirect/'. arg(2):
    case 'admin/build/path-redirect/edit/'. arg(3):
      return '<p>'. t("The <strong>from</strong> path must be an internal Drupal path in the form of 'node/123', 'admin/logs', or 'taxonomy/term/123'. The <strong>to</strong> path can be either an internal Drupal path as above or a complete external URL such as http://www.example.com/. Furthermore, the <strong>to</strong> path may contain query arguments (such as 'page=2') and fragment anchors, to make it possible to redirect to 'admin/user?page=1#help'. Most redirects will not contain queries or anchors.") .'</p>';
  }
}

/**
 * If a redirect is found for the current path, perform the redirect.
 */
function path_redirect_check() {
  // Extract the Drupal path and query string from the request URI.
  $path = drupal_substr(urldecode(request_uri()), drupal_strlen($GLOBALS['base_path']));
  if (preg_match('/^\?q=/', $path)) {
    $path = preg_replace(array('/^\?q=/', '/&/'), array('', '?'), $path, 1);
  }

  // Remove trailing slash from path.
  $path = preg_replace('/\/\?|\/$/', '', $path);

  $r = db_fetch_object(db_query("SELECT rid, redirect, query, fragment, type FROM {path_redirect} WHERE path = '%s' OR path = '%s'", $path, urlencode(utf8_encode($path))));
  if (!$r) {
    // If there is no match against path and query string, check just the path
    $path = preg_replace('/\?.*/', '', $path);
    $r = db_fetch_object(db_query("SELECT rid, redirect, query, fragment, type FROM {path_redirect} WHERE path = '%s' OR path = '%s'", $path, urlencode(utf8_encode($path))));
  }

  if ($r) {
    drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
    $r->query = strlen($r->query) ? $r->query : NULL;
    $r->fragment = strlen($r->fragment) ? $r->fragment : NULL;
    $redirect = url($r->redirect, $r->query, $r->fragment, TRUE);
    if (url($r->redirect) == url($path)) {
      // Prevent infinite loop redirection.
      watchdog('path_redirect', t('Redirect to <code>%redirect</code> is causing an infinite loop; redirect cancelled.', array('%redirect' => $r->redirect)), WATCHDOG_WARNING, l(t('edit'), 'admin/build/path-redirect/edit/'. $r->rid));
    }
    elseif (variable_get('path_redirect_allow_bypass', 0) && isset($_GET['redirect']) && $_GET['redirect'] === 'no') {
      // If the user has requested not to be redirected, show a message.
      drupal_set_message(t('This page has been redirected to <a href="@redirect">@redirect</a>.', array('@redirect' => $redirect)));
    }
    elseif (variable_get('path_redirect_redirect_warning', 0)) {
      // Show a message and automatically redirect after 5 seconds.
      drupal_set_message(t('This page has been moved to <a href="@redirect">@redirect</a> and will redirect in 5 seconds. You may want to update your bookmarks.', array('@redirect' => $redirect)), 'error');
      drupal_set_html_head("<meta http-equiv=\"refresh\" content=\"5;url=$redirect\" />");
    }
    else {
      // Perform the redirect directly.
      unset($_REQUEST['destination']);
      drupal_goto($r->redirect, $r->query, $r->fragment, $r->type);
    }
  }
}

/**
 * Implementation of hook_menu
 */
function path_redirect_menu($may_cache) {
  $access = user_access('administer redirects');
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/build/path-redirect',
      'title' => t('URL redirects'),
      'description' => t('Redirect users from one URL to another'),
      'callback' => 'path_redirect_admin',
      'access' => $access,
    );
    $items[] = array(
      'path' => 'admin/build/path-redirect/list',
      'title' => t('List'),
      'description' => t('List all URL redirects'),
      'access' => $access,
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'weight' => -3,
    );
    $items[] = array(
      'path' => 'admin/build/path-redirect/add',
      'title' => t('Add redirect'),
      'description' => t('Add a new URL redirect'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('path_redirect_edit'),
      'access' => $access,
      'type' => MENU_LOCAL_TASK,
    );
    $items[] = array(
      'path' => 'admin/build/path-redirect/edit',
      'title' => t('Edit'),
      'description' => t('Edit an existing URL redirect'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('path_redirect_edit'),
      'access' => $access,
      'type' => MENU_CALLBACK,
    );
    $items[] = array(
      'path' => 'admin/build/path-redirect/delete',
      'title' => t('Delete'),
      'description' => t('Delete an existing URL redirect'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('path_redirect_delete_confirm'),
      'access' => $access,
      'type' => MENU_CALLBACK,
    );
    $items[] = array(
      'path' => 'admin/build/path-redirect/settings',
      'title' => t('Settings'),
      'description' => t('Configure behavior for URL redirects'),
      'callback' => 'drupal_get_form',
      'callback arguments' => 'path_redirect_settings',
      'access' => $access,
      'type' => MENU_LOCAL_TASK,
    );
  }
  else {
    path_redirect_check();
  }
  return $items;
}

/**
 * Implementation of hook_perm
 */
function path_redirect_perm() {
  return array('administer redirects');
}

/**
 * Render a list of redirects for the main admin page.
 */
function path_redirect_admin() {
  $header = array(
    array('data' => t('From'), 'field' => 'path', 'sort' => 'asc'),
    array('data' => t('To'), 'field' => 'redirect'),
    array('data' => t('Type'), 'field' => 'type'),
    array('data' => t('Operations'), 'colspan' => '2'),
  );

  $result = pager_query('SELECT rid, path, redirect, query, fragment, type FROM {path_redirect}'. tablesort_sql($header), 50);

  $rows = array();
  while ($r = db_fetch_object($result)) {
    $redirect = url($r->redirect, ($r->query ? $r->query : NULL), ($r->fragment? $r->fragment : NULL), TRUE);
    $rows[] = array(
      // @todo: Revise the following messy, confusing line.
      l($r->path, preg_replace('/\?.*/', '', $r->path), array(), strstr($r->path, '?') ? preg_replace('/.*\?/', '', $r->path) : NULL),
      l($redirect, $redirect),
      $r->type,
      l(t('edit'), 'admin/build/path-redirect/edit/'. $r->rid),
      l(t('delete'), 'admin/build/path-redirect/delete/'. $r->rid),
    );
  }

  if (empty($rows)) {
    $rows[] = array(array('data' => t('No redirects have been added.'), 'colspan' => '5'));
  }

  $output = theme('table', $header, $rows, array('class' => 'path-redirects'));
  $output .= '<p>'. l(t('Add redirect'), 'admin/build/path-redirect/add') .'</p>';
  $output .= theme('pager');

  return $output;
}

/**
 * Callback for add and edit pages.
 *
 * @return
 *   A form for drupal_get_form.
 */
function path_redirect_edit($rid = FALSE) {
  if ($rid) {
    $redirect = path_redirect_load($rid);
    drupal_set_title(check_plain($redirect['path']));
    $output = path_redirect_edit_form($redirect);
  }
  else {
    $breadcrumbs = drupal_get_breadcrumb();
    array_push($breadcrumbs, l(t('URL redirects'), 'admin/build/path-redirect'));
    drupal_set_breadcrumb($breadcrumbs);
    drupal_set_title(t('Add redirect'));
    $output = path_redirect_edit_form();
  }
  return $output;
}

function path_redirect_edit_form($edit = array('path' => '', 'redirect' => '', 'query' => '', 'fragment' => '', 'type' => PATH_REDIRECT_DEFAULT_TYPE, 'rid' => NULL)) {
  $form['path'] = array(
    '#type' => 'textfield',
    '#title' => t('From'),
    '#description' => t('Enter a Drupal path or path alias to redirect. Fragment anchors <em>#foo</em> are <strong>not</strong> allowed.'),
    '#size' => 42,
    '#maxlength' => 255,
    '#default_value' => $edit['path'],
    '#field_prefix' => url(NULL, NULL, NULL, TRUE) . (variable_get('clean_url', 0) ? '' : '?q='),
  );

  $form['redirect'] = array(
    '#type' => 'item',
    '#prefix' => '<div class="container-inline">',
    '#suffix' => '</div>',
    '#title' => t('To'),
    '#description' => '<div style="display:block">'. t('Enter a Drupal path, path alias, or external URL to redirect to. Use %front to redirect to the front page. Enter (optional) queries after "?" and (optional) anchor after "#". Most redirects will not contain queries or fragment anchors.', array('%front' => '<front>')) .'</div>',
  );

  $form['redirect']['redirect'] = array(
    '#type' => 'textfield',
    '#size' => 30,
    '#maxlength' => 255,
    '#default_value' => $edit['redirect'],
  );

  $form['redirect'][] = array(
    '#value' => '?',
  );

  $form['redirect']['query'] = array(
    '#type' => 'textfield',
    '#size' => 12,
    '#maxlength' => 255,
    '#default_value' => $edit['query'],
  );

  $form['redirect'][] = array(
    '#value' => '#',
  );

  $form['redirect']['fragment'] = array(
    '#type' => 'textfield',
    '#size' => 12,
    '#maxlength' => 50,
    '#default_value' => $edit['fragment'],
  );

  $form[] = array(
    '#value' => "<p> </p>", // little bit of extra space
  );

  $form['type'] = array(
    '#type' => 'fieldset',
    '#title' => t('Redirect Type'),
    '#collapsible' => TRUE,
    '#collapsed' => ($edit['type'] == PATH_REDIRECT_DEFAULT_TYPE),
  );

  foreach (path_redirect_status_codes() as $key => $info) {
    $form['type'][]['type'] = array(
      '#type' => 'radio',
      '#title' => $info['title'],
      '#description' => $info['description'],
      '#return_value' => $key,
      '#default_value' => $edit['type'],
    );
  }
  $form['type']['link'] = array(
    '#type' => 'markup',
    '#value' => t('<p>Find more information about http redirect codes <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3">here</a>.</p>'),
  );

  $form['rid'] = array(
    '#type' => 'hidden',
    '#value' => $edit['rid'],
  );

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => $edit['rid'] ? t('Update redirect') : t('Create new redirect'),
  );

  return $form;
}

function path_redirect_edit_validate($form_id, &$form_values, $form) {
  // Allow spaces in "from" path; encode everything but the query string
  $form_values['path'] = urlencode(preg_replace('/\?.*/', '', $form_values['path']))
    . (strstr($form_values['path'], '?') ? preg_replace('/.*(\?)/', '$1', $form_values['path']) : '');
  form_set_value($form['path'], $form_values['path']);

  if (trim($form_values['path']) == '') {
    form_set_error('path', t('You must enter a <strong>from</strong> path.'));
  }
  else {
    $path_error = '';

    // The "from" path should not conflict with another redirect
    $result = path_redirect_load(NULL, $form_values['path']);
    if ($result && (!$form_values['rid'] || ($form_values['rid'] !== $result['rid']))) {
      $path_error .= ' '. t('The <strong>from</strong> path you entered is already redirected. You can <a href="@edit-page">edit this redirect</a> instead.', array('@edit-page' => url('admin/build/path-redirect/edit/'. $result['rid'])));
    }
    // Check that the "from" path is valid and contains no # fragment
    if (strpos($form_values['path'], '#') !== FALSE) {
      $path_error .= ' '. t('You cannot redirect from a fragment anchor.');
    }
    // Make sure "from" has the form of a local Drupal path
    if (!valid_url($form_values['path'])) {
      $path_error .= ' '. t('The redirect <strong>from</strong> path does not appear valid. This must be a local Drupal path.');
    }

    if (!empty($path_error)) {
      form_set_error('path', $path_error);
    }
  }

  if (!valid_url($form_values['redirect']) && !valid_url($form_values['redirect'], TRUE) && $form_values['redirect'] != '<front>') {
    form_set_error('redirect', t('The redirect <strong>to</strong> path does not appear valid.'));
  }

  if ($form_values['redirect'] == '<front>') {
    $form_values['redirect'] = variable_get('site_frontpage', 'node');
  }

  // check that there there are no redirect loops
  if ($form_values['path'] === $form_values['redirect']) {
    form_set_error('redirect', t('You are attempting to redirect the page to itself. This will result in an infinite loop.'));
  }
}

function path_redirect_edit_submit($form_id, &$form_values) {
  path_redirect_save($form_values);
  drupal_set_message(t('Redirect has been saved.'));
  drupal_goto('admin/build/path-redirect');
}

function path_redirect_save($edit) {
  if (empty($edit['rid'])) {
    $edit['rid'] = db_next_id('{path_redirect}_rid');
  }
  else {
    path_redirect_delete(NULL, NULL, $edit['rid']);
  }

  if (empty($edit['type'])) {
    $edit['type'] = PATH_REDIRECT_DEFAULT_TYPE;
  }
  if (empty($edit['query'])) {
    $edit['query'] = '';
  }
  if (empty($edit['fragment'])) {
    $edit['fragment'] = '';
  }

  // Remove any other redirects from the same path
  db_query("DELETE FROM {path_redirect} WHERE path = '%s'", $edit['path']);

  return db_query("INSERT INTO {path_redirect} (rid, path, redirect, query, fragment, type) VALUES (%d, '%s', '%s', '%s', '%s', '%s')", $edit['rid'], $edit['path'], $edit['redirect'], $edit['query'], $edit['fragment'], $edit['type']);
}

/**
 * Retrieve the specified URL redirect
 */
function path_redirect_load($rid = NULL, $from = NULL) {
  if (!empty($rid)) {
    $result = db_fetch_array(db_query("SELECT rid, path, redirect, query, fragment, type FROM {path_redirect} WHERE rid = %d", $rid));
  }
  else if (!empty($from)) {
    $result = db_fetch_array(db_query("SELECT rid, path, redirect, query, fragment, type FROM {path_redirect} WHERE path = '%s'", $from));
  }

  if ($result) {
    $result['path'] = urldecode($result['path']);
  }
  return $result;
}

/**
 * Delete the specified path redirect. This will delete as specifically as
 * possible, in order: by $rid, by ($from, $to), by $from, or by $to.
 * Multiple redirects may be deleted if the $to parameter matches more than
 * one entry.
 *
 * This function is part of an API available for external code to use.
 *
 * @param $from
 *   Source path of redirect to delete.
 * @param $to
 *   Destination path or URL of redirect to delete.
 * @param $rid
 *   Unique ID of redirect to delete.
 * @return
 *   The result of the deletion query.
 */
function path_redirect_delete($from = NULL, $to = NULL, $rid = NULL) {
  if (!empty($rid)) {
    $result = db_query("DELETE FROM {path_redirect} WHERE rid = %d", $rid);
  }
  else if (!empty($from)) {
    if (!empty($to)) {
      $result = db_query("DELETE FROM {path_redirect} WHERE path = '%s' AND redirect = '%s'", $from, $to);
    }
    else {
      $result = db_query("DELETE FROM {path_redirect} WHERE path = '%s'", $from);
    }
  }
  else if (!empty($to)) {
    $result = db_query("DELETE FROM {path_redirect} WHERE redirect = '%s'", $to);
  }
  return $result;
}

function path_redirect_delete_confirm($rid) {
  $form['rid'] = array(
    '#type' => 'value',
    '#value' => $rid,
  );
  $redirect = path_redirect_load($rid);
  return confirm_form($form,
    t('Are you sure you want to delete the redirect from %path to %redirect?', array('%path' => $redirect['path'], '%redirect' => $redirect['redirect'])),
    isset($_GET['destination']) ? $_GET['destination'] : 'admin/build/path-redirect');
}

function path_redirect_delete_confirm_submit($form_id, $form_values) {
  if ($form_values['confirm']) {
    path_redirect_delete(NULL, NULL, $form_values['rid']);
    drupal_set_message(t('The redirect has been deleted.'));
    return 'admin/build/path-redirect';
  }
}

function path_redirect_settings() {
  $form['path_redirect_nodeapi_enabled'] = array(
    '#type' => 'radios',
    '#title' => t('Enable on edit pages'),
    '#default_value' => variable_get('path_redirect_nodeapi_enabled', 0),
    '#options' => array(t('Disabled'), t('Enabled')),
    '#description' => t('Enable management of URL redirects directly on content editing pages.'),
  );

  $form['path_redirect_redirect_warning'] = array(
    '#type' => 'radios',
    '#title' => t('Warn on redirect'),
    '#default_value' => variable_get('path_redirect_redirect_warning', 0),
    '#options' => array(t('Disabled'), t('Enabled')),
    '#description' => t('Display a warning message to users when a redirect takes place.'),
  );

  $form['path_redirect_allow_bypass'] = array(
    '#type' => 'radios',
    '#title' => t('Allow bypassing'),
    '#default_value' => variable_get('path_redirect_allow_bypass', 0),
    '#options' => array(t('Disabled'), t('Enabled')),
    '#description' => t('Allow users to bypass redirects by appending <code>?redirect=no</code> to the URL.'),
  );

  return system_settings_form($form);
}

function path_redirect_form_alter($form_id, &$form) {
  if (variable_get('path_redirect_nodeapi_enabled', 0) && isset($form['#id']) && $form['#id'] == 'node-form' && user_access('administer redirects')) {
    $form['redirects'] = array(
      '#type' => 'fieldset',
      '#access' => user_access('administer redirects'),
      '#title' => t('URL redirects'),
      '#collapsible' => TRUE,
      '#collapsed' => !db_num_rows(path_redirect_node_redirects($form['#node']->nid)),
      '#prefix' => '<div class="path-redirects">',
      '#suffix' => '</div>',
      '#weight' => 31,
    );
    $form['redirects']['list'] = _path_redirect_node_form_list($form['#node']);
    $form['redirects']['path_redirect_add'] = array(
      '#type' => 'textfield',
      '#title' => t('Add a redirect from'),
      '#description' => t('Path from which to redirect to this node. Do not include the leading slash.'),
      '#maxlength' => 255,
      '#size' => 42,
    );
  }
}

function path_redirect_node_redirects($nid) {
  return db_query("
    SELECT rid, path, redirect, type
    FROM {path_redirect} pr LEFT JOIN {url_alias} ua ON pr.redirect = ua.dst
    WHERE pr.redirect = 'node/%d' OR ua.src = 'node/%d'
    ORDER BY pr.path", $nid, $nid);
}

function _path_redirect_node_form_list($node) {
  $form['#theme'] = 'path_redirect_node_form_list';
  if (!empty($node->nid)) {
    $result = path_redirect_node_redirects($node->nid);
    if ($result) {
      $destination = drupal_get_destination();
      $types = path_redirect_status_codes();
      while ($redirect = db_fetch_object($result)) {
        $form['redirects'][$redirect->rid]['path'] = array(
          '#value' => htmlspecialchars(urldecode($redirect->path)),
        );
        $form['redirects'][$redirect->rid]['redirect'] = array(
          '#value' => $redirect->redirect,
        );
        $form['redirects'][$redirect->rid]['type'] = array(
          '#value' => '<span title="'. $types[$redirect->type]['title'] .'">'. $redirect->type .'</span>',
        );
        $form['redirects'][$redirect->rid]['test'] = array(
          '#value' => l(t('test'), preg_replace('/\?.*/', '', urldecode($redirect->path)), NULL, strstr($redirect->path, '?') ? preg_replace('/.*\?/', '', $redirect->path) : NULL),
        );
        $form['redirects'][$redirect->rid]['edit'] = array(
          '#value' => l(t('edit'), 'admin/build/path-redirect/edit/'. $redirect->rid, array(), $destination),
        );
        $form['redirects'][$redirect->rid]['delete'] = array(
          '#value' => l(t('delete'), 'admin/build/path-redirect/delete/'. $redirect->rid, array(), $destination),
        );
      }
    }
  }
  return $form;
}

function theme_path_redirect_node_form_list(&$form) {
  if (count(element_children($form['redirects']))) {
    $header = array(
      t('From'),
      t('To'),
      t('Type'),
      array('data' => t('Operations'), 'colspan' => 3),
    );
    foreach (element_children($form['redirects']) as $key) {
      $rows[] = array(
        drupal_render($form['redirects'][$key]['path']),
        drupal_render($form['redirects'][$key]['redirect']),
        drupal_render($form['redirects'][$key]['type']),
        drupal_render($form['redirects'][$key]['test']),
        drupal_render($form['redirects'][$key]['edit']),
        drupal_render($form['redirects'][$key]['delete']),
      );
    }
    return theme('table', $header, $rows);
  }
}

function path_redirect_nodeapi(&$node, $op, $arg) {
  if (user_access('administer redirects')) {
    switch ($op) {
      case 'validate':
        if (db_result(db_query("SELECT COUNT(rid) FROM {path_redirect} WHERE path = '%s' AND redirect != '%s' AND redirect != '%s'", $node->path_redirect_add, "node/$node->nid", $node->path))) {
          form_set_error('path_redirect_add', t('The path is already redirected elsewhere.'));
        }
        break;
      case 'load':
        break;
      case 'update':
      case 'insert':
        if ($node->path_redirect_add) {
          path_redirect_save(array(
            'path' => $node->path_redirect_add,
            'redirect' => 'node/'. $node->nid,
            'type' => 301,
          ));
        }
        break;
      case 'delete':
        break;
    }
  }
}

/**
 * This is a copy of drupal_goto() redesigned for use during the bootstrap
 */
function path_redirect_goto($path = '', $query = NULL, $fragment = NULL, $http_response_code = 302) {

  $url = $path;

  // Make the given path or URL absolute
  if (!preg_match('/^[a-z]+:\/\//', $url)) {
    global $base_url;
    $url = $base_url .'/'. $url;
  }

  $url .= (empty($query)    ? '' : '?'. $query);
  $url .= (empty($fragment) ? '' : '#'. $fragment);

  // Remove newlines from the URL to avoid header injection attacks.
  $url = str_replace(array("\n", "\r"), '', $url);

  // Before the redirect, allow modules to react to the end of the page request.
  bootstrap_invoke_all('exit');

  // Even though session_write_close() is registered as a shutdown function, we
  // need all session data written to the database before redirecting.
  session_write_close();

  header('Location: '. $url, TRUE, $http_response_code);

  // The "Location" header sends a REDIRECT status code to the http
  // daemon. In some cases this can go wrong, so we make sure none
  // of the code below the drupal_goto() call gets executed when we redirect.
  exit();
}

/**
 * Return an array of 300-range status codes
 * placed here for clarity
 */
function path_redirect_status_codes() {
  $codes = array(
    300 => array('title' => t('300 Multiple Choices'), 'description' => t('The request is ambiguous and needs clarification as to which resource was requested.')),
    301 => array('title' => t('301 Moved Permanently'), 'description' => t('Moved Permanently. The resource has permanently moved elsewhere, the response indicates where it has gone to. <strong>Recommended.</strong>')),
    302 => array('title' => t('302 Found'), 'description' => t('The resource has temporarily moved elsewhere, the response indicates where it is at present. <strong>This is Drupal\'s default redirect type.</strong>')),
    303 => array('title' => t('303 See Other'), 'description' => t('See Other/Redirect. A preferred alternative source should be used at present.')),
    304 => array('title' => t('304 Not Modified'), 'description' => t('The server has identified from the request information that the client\'s copy of the information is up-to-date and the requested information does not need to be sent again.')),
    305 => array('title' => t('305 Use Proxy'), 'description' => t('The request must be sent through the indicated proxy server.')),
    307 => array('title' => t('307 Temporary Redirect'), 'description' => t('The resource has temporarily moved elsewhere, the response indicates where it is at present. Client should still use this URL.')),
  );

  return $codes;
}