gecko/netwerk/base/public/nsIChannelEventSink.idl

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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: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla.
*
* The Initial Developer of the Original Code is
* Netscape Communications.
* Portions created by the Initial Developer are Copyright (C) 2001
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Gagan Saksena <gagan@netscape.com> (original author)
* Darin Fisher <darin@netscape.com>
* Christian Biesinger <cbiesinger@web.de>
* Bjarne Geir Herland <bjarne@runitsoft.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#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(a430d870-df77-4502-9570-d46a8de33154)]
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;
/**
* 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);
};