uriloader/exthandler/nsIHandlerService.idl
author moz-wptsync-bot <wptsync@mozilla.com>
Mon, 16 Apr 2018 18:38:41 +0000
changeset 1486024 3a644abd5eaa108f67471c0aae4fb4a424ea41bf
parent 1310703 8129c43822454eed4d5db20f78474623be6606f4
child 1492904 9130a0ae777a70c5fa0c2ee3aa10200dfa85c321
child 1526804 d494c91279b21d1cc26e2a36ac0c24ce5c55c321
child 1549016 6e5891872dd9b6bec8d677ac0daa02fbe019e05f
child 1550242 ebb1e78e1818b32755efad4beab37ebb8d45e985
child 1778695 d1c2a809f217edeedcda409ed21acabcb6908f2e
child 1846909 17695ab8b21971a35960ca93a93b9f5dd739880b
child 1848314 08a68b6d992ef951b3e8538394e42b51f12da834
child 1864200 7645f05ea24cac70cf160fac990e04cb6c9895fd
permissions -rw-r--r--
Bug 1454380 [wpt PR 8508] - Update wpt metadata, a=testonly wpt-pr: 8508 wpt-type: metadata

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface nsIHandlerInfo;
interface nsISimpleEnumerator;

[scriptable, uuid(53f0ad17-ec62-46a1-adbc-efccc06babcd)]
interface nsIHandlerService : nsISupports
{
  /**
   * Asynchronously performs any IO that the nsIHandlerService needs to do
   * before it can be of use.
   */
  void asyncInit();

  /**
   * Retrieve a list of all handlers in the datastore.  This list is not
   * guaranteed to be in any particular order, and callers should not assume
   * it will remain in the same order in the future.
   *
   * @returns a list of all handlers in the datastore
   */
  nsISimpleEnumerator enumerate();

  /**
   * Fill a handler info object with information from the datastore.
   *
   * Note: because of the way the external helper app service currently mixes
   * OS and user handler info in the same handler info object, this method
   * takes an existing handler info object (probably retrieved from the OS)
   * and "fills it in" with information from the datastore, overriding any
   * existing properties on the object with properties from the datastore.
   *
   * Ultimately, however, we're going to separate OS and user handler info
   * into separate objects, at which point this method should be renamed to
   * something like "get" or "retrieve", take a class and type (or perhaps
   * a type whose class can be determined by querying the type, for example
   * an nsIContentType which is also an nsIMIMEType or an nsIProtocolScheme),
   * and return a handler info object representing only the user info.
   *
   * Note: if you specify an override type, then the service will fill in
   * the handler info object with information about that type instead of
   * the type specified by the object's nsIHandlerInfo::type attribute.
   *
   * This is useful when you are trying to retrieve information about a MIME
   * type that doesn't exist in the datastore, but you have a file extension
   * for that type, and nsIHandlerService::getTypeFromExtension returns another
   * MIME type that does exist in the datastore and can handle that extension.
   *
   * For example, the user clicks on a link, and the content has a MIME type
   * that isn't in the datastore, but the link has a file extension, and that
   * extension is associated with another MIME type in the datastore (perhaps
   * an unofficial MIME type preceded an official one, like with image/x-png
   * and image/png).
   *
   * In that situation, you can call this method to fill in the handler info
   * object with information about that other type by passing the other type
   * as the aOverrideType parameter.
   *
   * @param aHandlerInfo   the handler info object
   * @param aOverrideType  a type to use instead of aHandlerInfo::type
   *
   * Note: if there is no information in the datastore about this type,
   * this method throws NS_ERROR_NOT_AVAILABLE. Callers are encouraged to
   * check exists() before calling fillHandlerInfo(), to prevent spamming the
   * console with XPCOM exception errors.
   */
  void fillHandlerInfo(in nsIHandlerInfo aHandlerInfo,
                       in ACString aOverrideType);

  /**
   * Save the preferred action, preferred handler, possible handlers, and
   * always ask properties of the given handler info object to the datastore.
   * Updates an existing record or creates a new one if necessary.
   *
   * Note: if preferred action is undefined or invalid, then we assume
   * the default value nsIHandlerInfo::useHelperApp.
   *
   * @param aHandlerInfo  the handler info object
   */
  void store(in nsIHandlerInfo aHandlerInfo);

  /**
   * Whether or not a record for the given handler info object exists
   * in the datastore. If the datastore is corrupt (or some other error
   * is caught in the implementation), false will be returned.
   *
   * @param aHandlerInfo  a handler info object
   *
   * @returns whether or not a record exists
   */
  boolean exists(in nsIHandlerInfo aHandlerInfo);

  /**
   * Remove the given handler info object from the datastore.  Deletes all
   * records associated with the object, including the preferred handler, info,
   * and type records plus the entry in the list of types, if they exist.
   * Otherwise, it does nothing and does not return an error.
   *
   * @param aHandlerInfo  the handler info object
   */
  void remove(in nsIHandlerInfo aHandlerInfo);

  /**
   * Get the MIME type mapped to the given file extension in the datastore.
   *
   * XXX If we ever support extension -> protocol scheme mappings, then this
   * method should work for those as well.
   *
   * Note: in general, you should use nsIMIMEService::getTypeFromExtension
   * to get a MIME type from a file extension, as that method checks a variety
   * of other sources besides just the datastore.  Use this only when you want
   * to specifically get only the mapping available in the datastore.
   *
   * @param aFileExtension  the file extension
   *
   * @returns the MIME type, if any; otherwise returns an empty string ("").
   */
  ACString getTypeFromExtension(in ACString aFileExtension);

  /**
   * Whether or not there is a handler known to the OS for the
   * specified protocol type.
   *
   * @param aProtocolScheme scheme to check for support
   *
   * @returns whether or not a handler exists
   */
  boolean existsForProtocol(in ACString aProtocolScheme);
};