On Feb 21, 4:59 pm, Nikitas Liogkas <[EMAIL PROTECTED]> wrote:
> I believe you have to make the stream seekable (so that you can rewind
> it after you read it, in order for the POST request to be sent to the
> server properly), and, if you are using JavaScript, scriptable (so that
> we can access it from JavaScript).
>
> So, assuming you intercept the request before it is sent to the server,
> you would do something like:
> channel.QueryInterface(Components.interfaces.nsIUploadChannel);
> channel.uploadStream.QueryInterface(Components.interfaces.nsISeekableStream);
> var stream = Components.classes["@mozilla.org/scriptableinputstream;1"]
>
> .createInstance(Components.interfaces.nsIScriptableInputStream);
> stream.init(channel.uploadStream);
> channel.uploadStream.seek(Components.interfaces.nsISeekableStream.NS_SEEK_SET,
> 0);
>
> ...then read from stream: stream.read(...)
>
> ...and finally maybe set the POST body to something else, depending on
> what you read in, and allow the request to proceed:
> var stringStream =
> Components.classes["@mozilla.org/io/string-input-stream;1"]
> .createInstance(Components.interfaces.nsIStringInputStream);
> var newbody = <some string>;
> stringStream.setData(newbody, newbody.length);
>
> // have to rewind the stream before setting the new POST body
> channel.QueryInterface(Components.interfaces.nsIUploadChannel);
> channel.uploadStream.QueryInterface(Components.interfaces.nsISeekableStream);
> channel.uploadStream.seek(Components.interfaces.nsISeekableStream.NS_SEEK_SET,
> 0);
>
> channel.uploadStream.QueryInterface(Components.interfaces.nsIMIMEInputStream);
> channel.uploadStream.setData(stringStream);
>
I did try something like this but the setData part does not work. the
original POST data is sent to the server.
What is the correct way of modifying POST data. What I try to do is
to add some prefix value string for some name=value in the POST data.
Thanks,
Wayne
> Since you are using C++, you probably do not need to cast to
> nsIScriptableInputStream at the beginning.
>
> HTH
>
> nikitas
>
> [EMAIL PROTECTED] wrote:
> > On Feb 20, 12:01 am, [EMAIL PROTECTED] wrote:
> >> Hi,
>
> >> Can you please tell me how can I get the HTTP Post data from a http
> >> observer?
>
> >> Thank you.
>
> > I did some research, and come up the following code.
> > But when i read the UploadStream, it always return 0. I have checked
> > via etheral, there is post data, but my code just is not able to read
> > it.
>
> > Can you please tell me what did I do wrong?
>
> > here is an overview of what I did:
> > 1. cast the observer subject to be a nsIUploadChannel
> > 2. get the Upload input Stream from the uploadChannel
> > 3. read from the upload input stream.
>
> > But i just get 0 when I read from the stream.
>
> > nsCAutoString requestMethod;
> > nsCOMPtr<nsIHttpChannel> channel =
> > do_QueryInterface(aSubject);
>
> > channel->GetRequestMethod(requestMethod);
>
> > FILE* log = fopen( "http.log", "a+");
>
> > if (requestMethod.Equals("POST") ) {
>
> > nsCOMPtr<nsIUploadChannel> uploadChannel =
> > do_QueryInterface(aSubject);
>
> > if (uploadChannel) {
> > nsCOMPtr<nsIInputStream> is;
> > uploadChannel->GetUploadStream(getter_AddRefs(is));
>
> > if(is) {
> > nsresult rv2;
>
> > PRUint32 numRead;
> > char buf[512];
> > fprintf (log, "%s POST ",uri);
> > while (1)
> > {
> > rv = is->Read(buf, sizeof(buf), &numRead);
> > if (NS_FAILED(rv))
> > {
> > printf("### error reading stream: %x\n", rv);
> > fprintf (log, " error ");
> > break;
> > }
>
> > if (numRead == 0) {
> > fprintf (log, " nothing ");
> > break;
> > }
>
> > buf[numRead -1]= '\0';
> > // buf now contains numRead bytes of data
> > fprintf (log, "%s",buf);
> > }
>
> > fprintf (log, "\n");
> > }
>
> > } else {
>
> > fprintf (log, "%s POST \n",uri);
> > }
>
> > } else {
> > fprintf (log, "%s\n",uri);
> > }
>
> > fclose(log);
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