/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* 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 "nsIRequest.idl" interface nsIURI; interface nsIInterfaceRequestor; interface nsIInputStream; interface nsIStreamListener; /** * The nsIChannel interface allows clients to construct "GET" requests for * specific protocols, and manage them in a uniform way. Once a channel is * created (via nsIIOService::newChannel), parameters for that request may * be set by using the channel attributes, or by QI'ing to a subclass of * nsIChannel for protocol-specific parameters. Then, the URI can be fetched * by calling nsIChannel::open or nsIChannel::asyncOpen. * * After a request has been completed, the channel is still valid for accessing * protocol-specific results. For example, QI'ing to nsIHttpChannel allows * response headers to be retrieved for the corresponding http transaction. * * This interface must be used only from the XPCOM main thread. */ [scriptable, uuid(06f6ada3-7729-4e72-8d3f-bf8ba630ff9b)] interface nsIChannel : nsIRequest { /** * The original URI used to construct the channel. This is used in * the case of a redirect or URI "resolution" (e.g. resolving a * resource: URI to a file: URI) so that the original pre-redirect * URI can still be obtained. This is never null. Attempts to * set it to null must throw. * * NOTE: this is distinctly different from the http Referer (referring URI), * which is typically the page that contained the original URI (accessible * from nsIHttpChannel). */ attribute nsIURI originalURI; /** * The URI corresponding to the channel. Its value is immutable. */ readonly attribute nsIURI URI; /** * The owner, corresponding to the entity that is responsible for this * channel. Used by the security manager to grant or deny privileges to * mobile code loaded from this channel. * * NOTE: this is a strong reference to the owner, so if the owner is also * holding a strong reference to the channel, care must be taken to * explicitly drop its reference to the channel. */ attribute nsISupports owner; /** * The notification callbacks for the channel. This is set by clients, who * wish to provide a means to receive progress, status and protocol-specific * notifications. If this value is NULL, the channel implementation may use * the notification callbacks from its load group. The channel may also * query the notification callbacks from its load group if its notification * callbacks do not supply the requested interface. * * Interfaces commonly requested include: nsIProgressEventSink, nsIPrompt, * and nsIAuthPrompt/nsIAuthPrompt2. * * When the channel is done, it must not continue holding references to * this object. * * NOTE: A channel implementation should take care when "caching" an * interface pointer queried from its notification callbacks. If the * notification callbacks are changed, then a cached interface pointer may * become invalid and may therefore need to be re-queried. */ attribute nsIInterfaceRequestor notificationCallbacks; /** * Transport-level security information (if any) corresponding to the channel. */ readonly attribute nsISupports securityInfo; /** * The MIME type of the channel's content if available. * * NOTE: the content type can often be wrongly specified (e.g., wrong file * extension, wrong MIME type, wrong document type stored on a server, etc.), * and the caller most likely wants to verify with the actual data. * * Setting contentType before the channel has been opened provides a hint * to the channel as to what the MIME type is. The channel may ignore this * hint in deciding on the actual MIME type that it will report. * * Setting contentType after onStartRequest has been fired or after open() * is called will override the type determined by the channel. * * Setting contentType between the time that asyncOpen() is called and the * time when onStartRequest is fired has undefined behavior at this time. * * The value of the contentType attribute is a lowercase string. A value * assigned to this attribute will be parsed and normalized as follows: * 1- any parameters (delimited with a ';') will be stripped. * 2- if a charset parameter is given, then its value will replace the * the contentCharset attribute of the channel. * 3- the stripped contentType will be lowercased. * Any implementation of nsIChannel must follow these rules. */ attribute ACString contentType; /** * The character set of the channel's content if available and if applicable. * This attribute only applies to textual data. * * The value of the contentCharset attribute is a mixedcase string. */ attribute ACString contentCharset; /** * The length of the data associated with the channel if available. A value * of -1 indicates that the content length is unknown. * * Callers should prefer getting the "content-length" property * as 64-bit value by QIing the channel to nsIPropertyBag2, * if that interface is exposed by the channel. */ attribute long contentLength; /** * Synchronously open the channel. * * @return blocking input stream to the channel's data. * * NOTE: nsIChannel implementations are not required to implement this * method. Moreover, since this method may block the calling thread, it * should not be called on a thread that processes UI events. Like any * other nsIChannel method it must not be called on any thread other * than the XPCOM main thread. * * NOTE: Implementations should throw NS_ERROR_IN_PROGRESS if the channel * is reopened. */ nsIInputStream open(); /** * Asynchronously open this channel. Data is fed to the specified stream * listener as it becomes available. The stream listener's methods are * called on the thread that calls asyncOpen and are not called until * after asyncOpen returns. If asyncOpen returns successfully, the * channel promises to call at least onStartRequest and onStopRequest. * * If the nsIRequest object passed to the stream listener's methods is not * this channel, an appropriate onChannelRedirect notification needs to be * sent to the notification callbacks before onStartRequest is called. * Once onStartRequest is called, all following method calls on aListener * will get the request that was passed to onStartRequest. * * If the channel's and loadgroup's notification callbacks do not provide * an nsIChannelEventSink when onChannelRedirect would be called, that's * equivalent to having called onChannelRedirect. * * If asyncOpen returns successfully, the channel is responsible for * keeping itself alive until it has called onStopRequest on aListener or * called onChannelRedirect. * * Implementations are allowed to synchronously add themselves to the * associated load group (if any). * * NOTE: Implementations should throw NS_ERROR_ALREADY_OPENED if the * channel is reopened. * * @param aListener the nsIStreamListener implementation * @param aContext an opaque parameter forwarded to aListener's methods * @see nsIChannelEventSink for onChannelRedirect */ void asyncOpen(in nsIStreamListener aListener, in nsISupports aContext); /************************************************************************** * Channel specific load flags: * * Bits 23-31 are reserved for future use by this interface or one of its * derivatives (e.g., see nsICachingChannel). */ /** * Set (e.g., by the docshell) to indicate whether or not the channel * corresponds to a document URI. */ const unsigned long LOAD_DOCUMENT_URI = 1 << 16; /** * If the end consumer for this load has been retargeted after discovering * its content, this flag will be set: */ const unsigned long LOAD_RETARGETED_DOCUMENT_URI = 1 << 17; /** * This flag is set to indicate that this channel is replacing another * channel. This means that: * * 1) the stream listener this channel will be notifying was initially * passed to the asyncOpen method of some other channel * * and * * 2) this channel's URI is a better identifier of the resource being * accessed than this channel's originalURI. * * This flag can be set, for example, for redirects or for cases when a * single channel has multiple parts to it (and thus can follow * onStopRequest with another onStartRequest/onStopRequest pair, each pair * for a different request). */ const unsigned long LOAD_REPLACE = 1 << 18; /** * Set (e.g., by the docshell) to indicate whether or not the channel * corresponds to an initial document URI load (e.g., link click). */ const unsigned long LOAD_INITIAL_DOCUMENT_URI = 1 << 19; /** * Set (e.g., by the URILoader) to indicate whether or not the end consumer * for this load has been determined. */ const unsigned long LOAD_TARGETED = 1 << 20; /** * If this flag is set, the channel should call the content sniffers as * described in nsNetCID.h about NS_CONTENT_SNIFFER_CATEGORY. * * Note: Channels may ignore this flag; however, new channel implementations * should only do so with good reason. */ const unsigned long LOAD_CALL_CONTENT_SNIFFERS = 1 << 21; /** * This flag tells the channel to use URI classifier service to check * the URI when opening the channel. */ const unsigned long LOAD_CLASSIFY_URI = 1 << 22; /** * Access to the type implied or stated by the Content-Disposition header * if available and if applicable. This allows determining inline versus * attachment. * * Implementations should throw NS_ERROR_NOT_AVAILABLE if the header either * doesn't exist for this type of channel or is empty, and * DISPOSITION_ATTACHMENT if an invalid/noncompliant value is present. */ readonly attribute unsigned long contentDisposition; const unsigned long DISPOSITION_INLINE = 0; const unsigned long DISPOSITION_ATTACHMENT = 1; /** * Access to the filename portion of the Content-Disposition header if * available and if applicable. This allows getting the preferred filename * without having to parse it out yourself. * * Implementations should throw NS_ERROR_NOT_AVAILABLE if the header doesn't * exist for this type of channel, if the header is empty, if the header * doesn't contain a filename portion, or the value of the filename * attribute is empty/missing. */ readonly attribute AString contentDispositionFilename; /** * Access to the raw Content-Disposition header if available and applicable. * * Implementations should throw NS_ERROR_NOT_AVAILABLE if the header either * doesn't exist for this type of channel or is empty. * * @deprecated Use contentDisposition/contentDispositionFilename instead. */ readonly attribute ACString contentDispositionHeader; };