/* -*- Mode: IDL; 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 "nsIStreamListener.idl" interface nsIChannel; interface nsIInputStream; /** * nsIStreamConverter provides an interface to implement when you have code * that converts data from one type to another. * * Suppose you had code that converted plain text into HTML. You could implement * this interface to allow everyone else to use your conversion logic using a * standard api. *

* STREAM CONVERTER USERS * * There are currently two ways to use a stream converter: *

    *
  1. SYNCHRONOUS Stream to Stream * You can supply the service with a stream of type X * and it will convert it to your desired output type and return * a converted (blocking) stream to you.
  2. * *
  3. ASYNCHRONOUS nsIStreamListener to nsIStreamListener * You can supply data directly to the converter by calling it's * nsIStreamListener::OnDataAvailable() method. It will then * convert that data from type X to your desired output type and * return converted data to you via the nsIStreamListener you passed * in by calling its OnDataAvailable() method.
  4. *
*

* * STREAM CONVERTER SUPPLIERS * * Registering a stream converter: * Stream converter registration is a two step process. First of all the stream * converter implementation must register itself with the component manager using * a contractid in the format below. Second, the stream converter must add the contractid * to the registry. * * Stream converter contractid format (the stream converter root key is defined in this * file): * *

@mozilla.org/streamconv;1?from=FROM_MIME_TYPE&to=TO_MIME_TYPE
* * @author Jud Valeski * @see nsIStreamConverterService */ [scriptable, uuid(0b6e2c69-5cf5-48b0-9dfd-c95950e2cc7b)] interface nsIStreamConverter : nsIStreamListener { /** * SYNCRONOUS VERSION * Converts a stream of one type, to a stream of another type. * * Use this method when you have a stream you want to convert. * * @param aFromStream The stream representing the original/raw data. * @param aFromType The MIME type of aFromStream. * @param aToType The MIME type of the returned stream. * @param aCtxt Either an opaque context, or a converter specific context * (implementation specific). * @return The converted stream. NOTE: The returned stream may not * already be converted. An efficient stream converter * implementation will converter data on demand rather than * buffering the converted data until it is used. */ nsIInputStream convert(in nsIInputStream aFromStream, in string aFromType, in string aToType, in nsISupports aCtxt); /** * ASYNCRONOUS VERSION * Converts data arriving via the converter's nsIStreamListener::OnDataAvailable() * method from one type to another, pushing the converted data out to the caller * via aListener::OnDataAvailable(). * * Use this method when you want to proxy (and convert) nsIStreamListener callbacks * asynchronously. * * @param aFromType The MIME type of the original/raw data. * @param aToType The MIME type of the converted data. * @param aListener The listener who receives the converted data. * @param aCtxt Either an opaque context, or a converter specific context * (implementation specific). */ void asyncConvertData(in string aFromType, in string aToType, in nsIStreamListener aListener, in nsISupports aCtxt); /** * Returns the content type that the stream listener passed to asyncConvertData will * see on the channel if the conversion is being done from aFromType to * /*. * * @param aFromType The type of the content prior to conversion. * @param aChannel The channel that we'd like to convert. May be null. * * @throws if the converter does not support conversion to * /* or if it doesn't know * the type in advance. */ ACString getConvertedType(in ACString aFromType, in nsIChannel aChannel); }; %{C++ #define NS_ISTREAMCONVERTER_KEY "@mozilla.org/streamconv;1" %}