Sending audio from a Swift App to PHP Server, and somewhere the audio is lost

Question

I am making an App in Swift that records some audio and then sends that recording to my PHP server.

The App records the audio clip fine (it can be played back with n

Answer 1

Your PHP code is mostly fine. The $_FILES part is OK, but php://input is not available with enctype="multipart/form-data".

The problem is with how you are generating the HTTP request in your Swift code. Mainly the HTTP headers. When creating the headers for multipart data, the pattern is this (if we choose AAAAA to be our boundary):

• Our chosen boundary: "AAAAA"
• Content Type = "multipart/form-data;boundary=AAAAA"
• Beginning Bounary = --AAAAA
• Ending Boundary = --AAAAA--

So by fixing up your code a little bit:

// This was your main problem
let boundary = "--------14737809831466499882746641449----"
let beginningBoundary = "--\(boundary)"
let endingBoundary = "--\(boundary)--"
let contentType = "multipart/form-data;boundary=\(boundary)"

// recordedFilePath is Optional, so the resulting string will end up being 'Optional("/path/to/file/filename.m4a")', which is wrong.
// We could just use currentFilename if we wanted
let filename = recordedFilePath ?? currentFilename
var header = "Content-Disposition: form-data; name=\"\(currentFilename)\"; filename=\"\(recordedFilePath!)\"\r\n"

var body = NSMutableData()
body.appendData(("\(beginningBoundary)\r\n" as NSString).dataUsingEncoding(NSUTF8StringEncoding)!)
body.appendData((header as NSString).dataUsingEncoding(NSUTF8StringEncoding)!)
body.appendData(("Content-Type: application/octet-stream\r\n\r\n" as NSString).dataUsingEncoding(NSUTF8StringEncoding)!)
body.appendData(recording!) // adding the recording here
body.appendData(("\r\n\(endingBoundary)\r\n" as NSString).dataUsingEncoding(NSUTF8StringEncoding)!)

var request = NSMutableURLRequest()
request.URL = sendToURL
request.HTTPMethod = "POST"
request.addValue(contentType, forHTTPHeaderField: "Content-Type")
request.addValue(recId, forHTTPHeaderField: "REC-ID") // recId is defined elsewhere
request.HTTPBody = body

In case you run into things like this again, when debugging networking code like this, I like to use tools that let me inspect the HTTP Network data being transferred. I personally like HTTPScoop because its simple, but you can also use BurpSuite or Charles

I just ran your code through, and compared the HTTP traffic with what happened when I made the request with curl

curl -X POST http://localhost/\~cjwirth/catch.php -F "file=@Untitled.m4a"