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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 cin: */
/* 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 nsIChannel;
interface nsIAsyncVerifyRedirectCallback;
/**
* Implement this interface to receive control over various channel events.
* Channels will try to get this interface from a channel's
* notificationCallbacks or, if not available there, from the loadGroup's
* notificationCallbacks.
*
* These methods are called before onStartRequest.
*/
[scriptable, uuid(0197720d-37ed-4e75-8956-d0d296e4d8a6)]
interface nsIChannelEventSink : nsISupports
{
/**
* This is a temporary redirect. New requests for this resource should
* continue to use the URI of the old channel.
*
* The new URI may be identical to the old one.
*/
const unsigned long REDIRECT_TEMPORARY = 1 << 0;
/**
* This is a permanent redirect. New requests for this resource should use
* the URI of the new channel (This might be an HTTP 301 reponse).
* If this flag is not set, this is a temporary redirect.
*
* The new URI may be identical to the old one.
*/
const unsigned long REDIRECT_PERMANENT = 1 << 1;
/**
* This is an internal redirect, i.e. it was not initiated by the remote
* server, but is specific to the channel implementation.
*
* The new URI may be identical to the old one.
*/
const unsigned long REDIRECT_INTERNAL = 1 << 2;
/**
* This is a special-cased redirect coming from hitting HSTS upgrade
* redirect from http to https only. In some cases this type of redirect
* may be considered as safe despite not being the-same-origin redirect.
*/
const unsigned long REDIRECT_STS_UPGRADE = 1 << 3;
/**
* Called when a redirect occurs. This may happen due to an HTTP 3xx status
* code. The purpose of this method is to notify the sink that a redirect
* is about to happen, but also to give the sink the right to veto the
* redirect by throwing or passing a failure-code in the callback.
*
* Note that vetoing the redirect simply means that |newChannel| will not
* be opened. It is important to understand that |oldChannel| will continue
* loading as if it received a HTTP 200, which includes notifying observers
* and possibly display or process content attached to the HTTP response.
* If the sink wants to prevent this loading it must explicitly deal with
* it, e.g. by calling |oldChannel->Cancel()|
*
* There is a certain freedom in implementing this method:
*
* If the return-value indicates success, a callback on |callback| is
* required. This callback can be done from within asyncOnChannelRedirect
* (effectively making the call synchronous) or at some point later
* (making the call asynchronous). Repeat: A callback must be done
* if this method returns successfully.
*
* If the return value indicates error (method throws an exception)
* the redirect is vetoed and no callback must be done. Repeat: No
* callback must be done if this method throws!
*
* @see nsIAsyncVerifyRedirectCallback::onRedirectVerifyCallback()
*
* @param oldChannel
* The channel that's being redirected.
* @param newChannel
* The new channel. This channel is not opened yet.
* @param flags
* Flags indicating the type of redirect. A bitmask consisting
* of flags from above.
* One of REDIRECT_TEMPORARY and REDIRECT_PERMANENT will always be
* set.
* @param callback
* Object to inform about the async result of this method
*
* @throw <any> Throwing an exception will cause the redirect to be
* cancelled
*/
void asyncOnChannelRedirect(in nsIChannel oldChannel,
in nsIChannel newChannel,
in unsigned long flags,
in nsIAsyncVerifyRedirectCallback callback);
};