gecko/dom/interfaces/storage/nsIDOMStorage.idl

/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 *   Neil Deakin <enndeakin@sympatico.ca>
 * Portions created by the Initial Developer are Copyright (C) 2006
 * the Initial Developer. All Rights Reserved.
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 *
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#include "domstubs.idl"

/**
 * Interface for client side storage. See
 * http://www.whatwg.org/specs/web-apps/current-work/#scs-client-side
 * for more information.
 *
 * A storage object stores an arbitrary set of key-value pairs, which
 * may be retrieved, modified and removed as needed. A key may only
 * exist once within a storage object, and only one value may be
 * associated with a particular key. Keys are stored in a particular
 * order with the condition that this order not change by merely changing
 * the value associated with a key, but the order may change when a
 * key is added or removed.
 */

interface nsIDOMStorageItem;

[scriptable, uuid(95CC1383-3B62-4B89-AAEF-1004A513EF47)]
interface nsIDOMStorage : nsISupports
{
  /**
   * The number of keys stored.
   */
  readonly attribute unsigned long length;

  /**
   * Retrieve the name of the key at a particular index.
   *
   * @param index index of the item to retrieve
   * @returns the key at index
   * @throws INDEX_SIZE_ERR if there is no key at that index
   */
  DOMString key(in unsigned long index);

  /**
   * Retrieve an item with a given key
   *
   * @param key key to retrieve
   * @returns found item or null if the key was not found
   */
  nsIDOMStorageItem getItem(in DOMString key);

  /**
   * Assign a value with a key. If the key does not exist already, a new
   * key is added associated with that value. If the key already exists,
   * then the existing value is replaced with a new value.
   *
   * @param key key to set
   * @param data data to associate with the key
   * @returns found item or null if the key was not found
   */
  void setItem(in DOMString key, in DOMString data);

  /**
   * Remove a key and its corresponding value.
   *
   * @param key key to remove
   */
  void removeItem(in DOMString key);
};