HTTP Post request structure

[alav]

Hello,

I am trying to send a request via HTTP Post. The session and transaction are created and submitted correctly, as I do execute a php script waiting on a www server. However, the structure of the request body seems to be incorrect, as I can't read POST variables in my script. When I send the request via web browser everything is correct, so the problem is in my code.

I've read and used the HTTP Client Example, but they don't construct a Post request there, they leave it to the user submitting the data using GUI.

Here's how I construct the request body (it's for testing purposes only):

delete iPostData;
TBuf8<1024> tmp;
_LIT8(KPost1, "--------------1345234fsf342\n");
_LIT8(KPost2, "Content-Disposition: form-data; name=\"latitude\"\n\n");
_LIT8(KPost3, "22.5");
_LIT8(KPost4, "--------------1345234fsf342--");
tmp.Copy(KPost1);
tmp.Append(KPost2);
tmp.Append(KPost3);
tmp.Append(KPost4);

iPostData = tmp.AllocL();

_LIT8(KUrl, "http://myscript.com");
TUriParser8 uri;
uri.Parse(KUrl);

RStringF method = iSession.StringPool().StringF(HTTP::EPOST,
RHTTPSession::GetTable());

iTransaction = iSession.OpenTransactionL(uri, *this, method);

_LIT8(KUserAgent, "MyClient");
_LIT8(KAccept, "*/*");
_LIT8(KMimeType, "multipart/form-data; boundary =--------------1345234fsf342");

RHTTPHeaders hdr = iTransaction.Request().GetHeaderCollection();
SetHeaderL(hdr, HTTP::EUserAgent, KUserAgent);
SetHeaderL(hdr, HTTP::EAccept, KAccept);
SetHeaderL(hdr, HTTP::EContentType, KMimeType);

MHTTPDataSupplier* dataSupplier = this;
iTransaction.Request().SetBody(*dataSupplier);

// Submit the transaction. After this the framework will give transaction
// events via MHFRunL and MHFRunError.
iTransaction.SubmitL();

/////

GetNextDataPart(TPtrC8 &aDataPart)
{

aDataPart.Set(iPostData->Des());

return ETrue;

}


Can you see any errors?

Maciej

[wizard_hu_]

Note that multipart uses the boundary-string as --boundary-string for marking continuation and --boundary-string-- for marking the last part. You have 14 hyphens everywhere.

[alav]

Indeed, that was the case, and some missing new line signs as well. Thank you.

Now I am able to transfer all my data successfully. However, if I send my image encoded using the base64 algorithm, the webserver doesn't recognize it as an image... It is saved on the server, but it can't be read as JPG.

Here's how I put it in the request body:

_LIT8(KNewLine, "\n");
_LIT8(KPost1, "--1345234fsf342\n");
_LIT8(KPost2, "Content-Disposition: form-data; name=\"photo\"; filename=\"test.jpg\"\nContent-Transfer-Encoding: base64\n\n");
_LIT8(KPost3, "--1345234fsf342--\n");

tmp.Append(KPost1);
tmp.Append(KPost2);
tmp.Append(aPhoto);
tmp.Append(KNewLine);
tmp.Append(KPost3);

where aPhoto is a Ptr8 containing a base64 encoded photo.

If I send the base64 string directly, as text/plain, save it in a file on the webserver and use an external base64 decoder, the image is decoded correctly - so it is not a matter of encoding error.

I suppose that I am putting the image data in the request body in an incorrect way and because of that the webserver can't read it in a proper way, it just decodes it to a file of an unrecognizable format.

Are you able to spot any errors in my code?

Maciej

[alav]

I saved the request body to a file to see if it's correct, here it goes:

--1345234fsf342
Content-Disposition: form-data; name="latitude"

22.5
--1345234fsf342
Content-Disposition: attachment; name="photo"; filename="ph.jpg"
Content-Type: image/jpeg
Content-Transfer-Encoding: base64

/9j/4RATRXhpZgAASUkqAAgAAAAIAA8BAgAGAAAAbgAAABABAgAEAAAARTUwABIBAwABAAAAAQA
AABoBBQABAAAAdAAAABsBBQABAAAAfAAAACgBAwABAAAAAgAAABMCAwABAAAAA[...]QLU
N4o3igBpamlqBWP//Z
--1345234fsf342
Content-Disposition: form-data; name="longitude"

123.54
--1345234fsf342--

Is there anything wrong?

[wizard_hu_]

Sorry I have absolutely no idea how HTTP POST works on the server side, let us hope that others know and they are going to share...

[alav]

There is a very useful tool named Live HTTP Headers - http://livehttpheaders.mozdev.org/

It lets you track the requests made by the browser. That's how I finally managed to make my post requests work - I just made a form which executed my script and viewed the request.

It didn't differ a lot, actually, but I saw that the browser doesn't use the base64 encoding, so I gave up on it and decided to send binary data. It works fine now, with the same structure as posted above, the only difference is:

----1345234fsf342
Content-Disposition: form-data; name="photo"; filename="ph.jpg"
Content-Type: image/jpeg

Without specifying encription type.

[lucca99]

Hi Alav,

I also need to upload a file from a cellphone to a server over http.
My file is e.g. C:\\Data\\myFile.xml
and I have also an uploadscript.php on the server
e.g. www. mydomain.com/myapp/uploadscript.php

Could you please give me a brief summary of how to make this happened?

It would be highly appreciated!
Cheers, Luuca

[raysky]

Indeed, that was the case, and some missing new line signs as well. Thank you.

Now I am able to transfer all my data successfully. However, if I send my image encoded using the base64 algorithm, the webserver doesn't recognize it as an image... It is saved on the server, but it can't be read as JPG.

Here's how I put it in the request body:

_LIT8(KNewLine, "\n");
_LIT8(KPost1, "--1345234fsf342\n");
_LIT8(KPost2, "Content-Disposition: form-data; name=\"photo\"; filename=\"test.jpg\"\nContent-Transfer-Encoding: base64\n\n");
_LIT8(KPost3, "--1345234fsf342--\n");

tmp.Append(KPost1);
tmp.Append(KPost2);
tmp.Append(aPhoto);
tmp.Append(KNewLine);
tmp.Append(KPost3);

where aPhoto is a Ptr8 containing a base64 encoded photo.

If I send the base64 string directly, as text/plain, save it in a file on the webserver and use an external base64 decoder, the image is decoded correctly - so it is not a matter of encoding error.

I suppose that I am putting the image data in the request body in an incorrect way and because of that the webserver can't read it in a proper way, it just decodes it to a file of an unrecognizable format.

Are you able to spot any errors in my code?

Maciej

hi can u share with me on how u managed to get the right string representation for "aPhoto"?

thanks =)

			RFileReadStream inputStream(iFile);
			MStreamBuf* streamBuf;

			aSize=aSize/500;
			HBufC8* mediaFile;
			mediaFile=HBufC8::NewLC(aSize);
			TPtr8 bufferPtr(mediaFile->Des());
			//iFile.Read(bufferPtr);
			streamBuf=inputStream.Source();
			TRequestStatus readStatus;
			streamBuf->Read(bufferPtr,readStatus);
			User::WaitForRequest(readStatus);
			streamBuf->Close();
			inputStream.Release();

i've tried this way but no luck....
i get some sort of string but when i use that to upload to my server the byte size seems too small...

pls help