drupal/modules/path.module

<?php
/* $Id$ */

function path_admin() {
  $op = strtolower($_POST["op"]);
  $edit = $_POST["edit"];

  if (user_access("alias urls")) {

    if (empty($op)) {
      $op = arg(2);
    }

    switch ($op) {
      case t("add"):
        $output = path_form();
        break;

      case t("edit"):
        $output = path_form(object2array(get_path_from_id(arg(3))));
        break;

      case t("delete"):
        if ($edit["confirm"]) {
          if (path_delete($edit['pid'])) {
            $output .= status("Deleted path '". $edit['dst'] ."'");
          }
        }
        else {
          $output .= path_confirm_delete(arg(3));
        }
        break;

      case t("create new alias"):
        $output = status(path_save($edit));
        // fall-through

      default:
        $output .= path_overview();
    }

    return $output;
  }
  else {
    return message_access();
  }
}

/**
 * Returns a path that is acceptable as an url.
 */
function path_clean($path) {
  global $base_url;

  /*
  ** Replace absolute URL for this site with relative URL.
  */
  $path = str_replace($base_url, "", $path);

  /*
  ** Only allow alpha numeric characters, slashes and underscores.
  */
  $path = preg_replace("'[^a-zA-Z0-9/_.]'", " ", $path);

  /*
  ** Remove all whitespace.
  */
  $path = str_replace(" ", "", $path);

  /*
  ** Replace two or more sequential slashes with only one slashes.
  */
  $path = preg_replace("'//*'","/",$path);

  /*
  ** Remove beginning and trailing slashes.
  */
  $path = trim($path, "/");

  return $path;
}

function path_confirm_delete($id) {
  $path = get_path_from_id($id);

  $form .= form_hidden("confirm", 1);
  $form .= form_hidden("pid", $id);
  $form .= form_hidden("src", $path->src);
  $form .= form_hidden("dst", $path->dst);
  $form .= form_submit(t("Delete"));
  $form .= form_submit(t("Cancel"));

  return form(form_item(t("Delete alias '%dst' that maps to '%src'", array("%dst" => $path->dst, "%src" => $path->src)), $form, t("Are you sure you want to delete this alias?")));
}

function path_delete($pid) {
  return db_query("DELETE FROM {path} WHERE pid = '%d'", $pid);
}

function path_help($section = "admin/path/help") {
  switch ($section) {
    case "admin/system/modules":
      $output = "Enables users to create custom URLs.";
      break;
    case "admin/system/modules/path":
      $output = "Documentation yet to be written.";
      break;
    case "admin/path/help":
      $output = "Documentation yet to be written.";
      break;
  }

  return t($output);
}

function path_form($edit = "") {
  $form .= form_textfield(t("Existing path"), "src", $edit["src"], 50, 64, t("Specify the existing path you wish to alias. For example: node/view/28, forum/1, taxonomy/page/or/1,2."));
  $form .= form_textfield(t("New path alias"), "dst", $edit["dst"], 50, 64, t("Specify an alternative path by which this data can be accessed.  For example, type 'about' when writing an about page."));
  $form .= form_hidden("pid", $edit["pid"]);
  $form .= form_submit(t("Create new alias"));

  if ($edit["pid"]) {
    $form .= form_submit(t("Delete"));
  }

  return form($form);
}

function path_insert($edit) {
  return db_query("INSERT INTO {path} SET src = '%s', dst = '%s'", $edit["src"], $edit["dst"]);
}

# DELETE
function path_is_unique($path, $type) {
  if ($type == "dst") {
    return !(get_src_url($path));
  }
  elseif ($type == "src") {
    return !(get_url_alias($path));
  }
}

function path_link($type, $node = NULL) {
  if ($type == "system" && user_access("alias urls")) {
    menu("admin/path", t("url aliasing"), "path_admin", "", 4);
    menu("admin/path/add", t("new alias"), "path_admin", "");
  }
}

function path_perm() {
  return array("alias urls");
}

function path_overview() {
  $sql = "SELECT * FROM {path}";
  $header = array(
    array ("data" => t("alias"), "field" => "dst", "sort" => "asc"),
    array ("data" => t("maps to"), "field" => "src"),
    array("data" => t("operations"), "colspan" => 2)
  );
  $sql .= tablesort_sql($header);
  $result = pager_query($sql, 50);

  while ($data = db_fetch_object($result)) {
    $rows[] = array($data->dst, $data->src, l(t("edit"), "admin/path/edit/$data->pid"), l(t("delete"), "admin/path/delete/$data->pid"));
  }

  $pager = pager_display(NULL, 50, 0, "admin", tablesort_pager());
  if (!empty($pager)) {
    $rows[] = array(array("data" => $pager, "colspan" => 3));
  }

  return table($header, $rows);
}

function path_save($edit) {
  $dst = path_clean($edit["dst"]);
  $src = path_clean($edit["src"]);

  if ($src == NULL || !valid_url($src)) {
    return t("the specified path is not valid.");
  }

  if (db_result(db_query("SELECT COUNT(src) FROM {path} WHERE src = '%s'", $src))) {
    return t("the specified path is already aliased.");
  }

  if ($dst == NULL || !valid_url($dst)) {
    return t("the specified path alias is not valid.");
  }

  if (db_result(db_query("SELECT COUNT(dst) FROM {path} WHERE dst = '%s'", $dst))) {
    return t("the specified alias is already in use.");
  }

  if ($edit["pid"]) {
    path_update($src, $dst);
  }
  else { //Update the path
    path_insert($edit);
  }

  return t("you may access %src via %dst.", array("%src" => url($src), "%dst" => l($dst, url($dst))));
}

function path_system($field) {
  $system["description"] = path_help("admin/system/modules");
  $system["admin_help"] =  path_help("admin/system/modules/path");

  return $system[$field];
}

function path_update($edit) {
  if ($edit["pid"]) {
    return db_query("UPDATE {path} SET src = '%s', dst = '%s' WHERE pid = '%d'", $edit["src"], $edit["dst"], $edit["pid"]);
  }
  else { // intended for nodes
    return db_query("UPDATE {path} SET dst = '%s' WHERE src = '%s'", $edit["dst"], $edit["src"]);
  }
}

function get_path_from_id($id) {
  return db_fetch_object(db_query("SELECT * FROM {path} WHERE pid = '%d'", $id));
}

?>