Multipartform data not passing in all params to server-Swift 3 - swift

Question

My requirement is to upload a recorded audio file with a file name and duration to a server using REST API
The code I have to form the multipart form data is as below
private func createRequestBody(boundary:"--BXDFG", multidata:Data, mime:"audio/mp4", filePathKey:"file", filename:"test", metas:["title":"Mytitle","duration":"30"] -> Data {
var body = Data()
body.append(Data("--\(boundary)\r\n".utf8))
body.append(Data("Content-Disposition: form-data; name=\"\(filePathKey)\"; filename=\"\(filename)\"\r\n".utf8))
body.append(Data("Content-Type: \(mime)\r\n\r\n".utf8))
body.append(multidata)
body.append(Data("\r\n".utf8))
if (metas != nil) {
for (key, value) in metas! {
body.append(Data("--\(boundary)\r\n".utf8))
body.append(Data("Content-Disposition: form-data; name=\"\(key)\"\r\n".utf8))
body.append(Data((value as! String).utf8))
body.append(Data("\r\n".utf8))
}
}
body.append(Data("--\(boundary)--\r\n".utf8))
return body
}
What I am doing is passing the audio as NSDATA and in a for loop I am adding "title" and "duration" to the multipart form request
On server side, I have below code
#api.route('/upload/<userid>', methods=['POST'])
def upload(userid):
if request.method == 'POST':
if 'title' not in request.form:
return jsonify({'error': 'Need a valid title for uploaded file', 'code': 403})
if "title" is not passed in multipart form data then the server will return an error response.
In my case, even though, "title" is added as a part of the request, the data is not passed to the server and the server returns an error. If I just pass the audio data alone, removing the validation for "title" on server side, then the audio data is uploaded successfully to the server.
I am not able to understand why "title" and "data" are not passed to server
PS: The API request works fine in POSTMAN client.
Thanks

Answer 1

This solved my case
Replacing line
body.append(Data("Content-Disposition: form-data; name=\"\(key)\"\r\n".utf8))
to
body.append(Data("Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n".utf8))
Added and additional /r/n