netwerk/base/nsIChannelEventSink.idl

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* vim:set ts=4 sw=4 sts=4 cin: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsISupports.idl"
   8
   9 interface nsIChannel;
  10 interface nsIAsyncVerifyRedirectCallback;
  11
  12 /**
  13  * Implement this interface to receive control over various channel events.
  14  * Channels will try to get this interface from a channel's
  15  * notificationCallbacks or, if not available there, from the loadGroup's
  16  * notificationCallbacks.
  17  *
  18  * These methods are called before onStartRequest.
  19  */
  20 [scriptable, uuid(0197720d-37ed-4e75-8956-d0d296e4d8a6)]
  21 interface nsIChannelEventSink : nsISupports
  22 {
  23     /**
  24      * This is a temporary redirect. New requests for this resource should
  25      * continue to use the URI of the old channel.
  26      *
  27      * The new URI may be identical to the old one.
  28      */
  29     const unsigned long REDIRECT_TEMPORARY = 1 << 0;
  30
  31     /**
  32      * This is a permanent redirect. New requests for this resource should use
  33      * the URI of the new channel (This might be an HTTP 301 reponse).
  34      * If this flag is not set, this is a temporary redirect.
  35      *
  36      * The new URI may be identical to the old one.
  37      */
  38     const unsigned long REDIRECT_PERMANENT = 1 << 1;
  39
  40     /**
  41      * This is an internal redirect, i.e. it was not initiated by the remote
  42      * server, but is specific to the channel implementation.
  43      *
  44      * The new URI may be identical to the old one.
  45      */
  46     const unsigned long REDIRECT_INTERNAL = 1 << 2;
  47
  48     /**
  49      * This is a special-cased redirect coming from hitting HSTS upgrade
  50      * redirect from http to https only.  In some cases this type of redirect
  51      * may be considered as safe despite not being the-same-origin redirect.
  52      */
  53     const unsigned long REDIRECT_STS_UPGRADE = 1 << 3;
  54
  55     /**
  56      * This is a internal redirect used to handle http authentication retries.
  57      * Upon receiving a 401 or 407 the channel gets redirected to a new channel
  58      * (same URL) that performs the request with the appropriate credentials.
  59      * Auth retry to the server must be made after redirecting to a new channel
  60      */
  61     const unsigned long REDIRECT_AUTH_RETRY = 1 << 4;
  62
  63     /**
  64      * Called when a redirect occurs. This may happen due to an HTTP 3xx status
  65      * code. The purpose of this method is to notify the sink that a redirect
  66      * is about to happen, but also to give the sink the right to veto the
  67      * redirect by throwing or passing a failure-code in the callback.
  68      *
  69      * Note that vetoing the redirect simply means that |newChannel| will not
  70      * be opened. It is important to understand that |oldChannel| will continue
  71      * loading as if it received a HTTP 200, which includes notifying observers
  72      * and possibly display or process content attached to the HTTP response.
  73      * If the sink wants to prevent this loading it must explicitly deal with
  74      * it, e.g. by calling |oldChannel->Cancel()|
  75      *
  76      * There is a certain freedom in implementing this method:
  77      *
  78      * If the return-value indicates success, a callback on |callback| is
  79      * required. This callback can be done from within asyncOnChannelRedirect
  80      * (effectively making the call synchronous) or at some point later
  81      * (making the call asynchronous). Repeat: A callback must be done
  82      * if this method returns successfully.
  83      *
  84      * If the return value indicates error (method throws an exception)
  85      * the redirect is vetoed and no callback must be done. Repeat: No
  86      * callback must be done if this method throws!
  87      *
  88      * NOTE: originalURI isn't yet set on the new channel when
  89      * asyncOnChannelRedirect is called.
  90      *
  91      * @see nsIAsyncVerifyRedirectCallback::onRedirectVerifyCallback()
  92      *
  93      * @param oldChannel
  94      *        The channel that's being redirected.
  95      * @param newChannel
  96      *        The new channel. This channel is not opened yet.
  97      * @param flags
  98      *        Flags indicating the type of redirect. A bitmask consisting
  99      *        of flags from above.
 100      *        One of REDIRECT_TEMPORARY and REDIRECT_PERMANENT will always be
 101      *        set.
 102      * @param callback
 103      *        Object to inform about the async result of this method
 104      *
 105      * @throw <any> Throwing an exception will cause the redirect to be
 106      *        cancelled
 107      */
 108     void asyncOnChannelRedirect(in nsIChannel oldChannel,
 109                                 in nsIChannel newChannel,
 110                                 in unsigned long flags,
 111                                 in nsIAsyncVerifyRedirectCallback callback);
 112 };