nsIStreamConverter

IID:0b6e2c69-5cf5-48b0-9dfd-c95950e2cc7b
Inherits From:nsIStreamListener

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. 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.

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

This interface is implemented by the following components:


Methods

void asyncConvertData ( char* fromType , char* toType , nsIStreamListener listener , nsISupports ctxt ) nsIInputStream convert ( nsIInputStream fromStream , char* fromType , char* toType , nsISupports ctxt )

void asyncConvertData ( char* fromType , char* toType , nsIStreamListener listener , nsISupports ctxt )

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 listener::OnDataAvailable().

Use this method when you want to proxy (and convert) nsIStreamListener callbacks asynchronously.

Arguments:
fromType: The MIME type of the original/raw data.
toType: The MIME type of the converted data.
listener: The listener who receives the converted data.
ctxt: Either an opaque context, or a converter specific context (implementation specific).

nsIInputStream convert ( nsIInputStream fromStream , char* fromType , char* toType , nsISupports ctxt )

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.

Arguments:
fromStream: The stream representing the original/raw data.
fromType: The MIME type of fromStream.
toType: The MIME type of the returned stream.
ctxt: Either an opaque context, or a converter specific context (implementation specific).
Returns:
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.

Reference documentation is generated from Mozilla's source.

Add a note User Contributed Notes
No comments available

Copyright © 1999 - 2005 XULPlanet.com