uploading image to server with swift (php, json, swift)

Question

I am working on a project wherein I'd like to select an image and then upload it to the server. I am able to click the upload image button, select an image, and change the image in the iOS simulator but the upload fails. When I include a print(request) after the request.httpBody = creatBodyWithParams() statement, it shows that the original url has not changed. I am using XAMPP to set up a virtual server and php to communicate with it.

My code:

// upload image button clicked
@IBAction func edit_click(_ sender: Any) {

    // select image
    let picker = UIImagePickerController()
    picker.delegate = self

    //picker.sourceType = UIImagePickerControllerSourceType.photoLibrary
    picker.allowsEditing = true
    self.present(picker, animated: true, completion: nil)
}

// selected image
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    avaImg.image = info[UIImagePickerControllerEditedImage] as? UIImage
    self.dismiss(animated: true, completion: nil)

    // call function of uploading image file to server
    uploadImage()
}

// create body of HTTP request to upload image file
func createBodyWithParams(parameters: [String : String]?, filePathKey: String?, imageDataKey: NSData, boundary: String) -> NSData {

    let body = NSMutableData();

    if parameters != nil {
        for (key, value) in parameters! {
            body.appendString(string: "--\(boundary)\r\n")
            body.appendString(string: "Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n")
            body.appendString(string: "\(value)\r\n")
        }
    }

    let filename = "image.jpg"

    let mimetype = "image/jpg"

    body.appendString(string: "--\(boundary)\r\n")
    body.appendString(string: "Content-Disposition: form-data; name=\"\(filePathKey!)\"; filename=\"\(filename)\"\r\n")
    body.appendString(string: "Content-Type: \(mimetype)\r\n\r\n")
    body.append(imageDataKey as Data)
    body.appendString(string: "\r\n")

    body.appendString(string: "--\(boundary)--\r\n")

    return body
}

// upload image to server
func uploadImage() {

    let id = user!["id"] as! String

    let address = URL(string: "http://localhost/project/uploadImage.php")!
    var request = URLRequest(url: address)
    request.httpMethod = "POST"
    let param = ["id" : id]

    let boundary = "Boundary-\(NSUUID().uuidString)"

    request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

    let imageData = UIImageJPEGRepresentation(avaImg.image!, 0.5)

    if imageData == nil {
        return
    }

    request.httpBody = createBodyWithParams(parameters: param, filePathKey: "file", imageDataKey: imageData! as NSData, boundary: boundary) as Data

    // launch session
    let task = URLSession.shared.dataTask(with: request, completionHandler: { (data, response, error) in

        // get main queue to communicate back to user
        DispatchQueue.main.async {

            if error == nil {

                do {

                    let json = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary

                    guard let parseJSON = json else {

                        print("error while parsing")
                        return

                    }

                    print(parseJSON)

                } catch {

                    print("Caught an error: \(error)")

                }

            } else {

                print(error)

            }
        }
    })

    task.resume()

}

With the following extension:

// creating protocol of appending string to var of type data
extension NSMutableData {

    appendString(string : String) {

        let data = string.data(using: String.Encoding.utf8, allowLossyConversion: true)
        append(data!)

    }
}

I have consulted the following pages for help and have tried changing my code to reflect the differences in their approaches but I am left banging my head against the wall.

Uploading image with other parameters in SWIFT

Upload image with parameters in Swift

http://www.kaleidosblog.com/how-to-upload-images-using-swift-2-send-multipart-post-request

EDIT 1:

Forgot error message (dur): Caught an error: Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}

Error is occurring somewhere in the do statement. I think something is going on with the request because testing http://localhost/project/uploadImage.php in my browser returns the array {"message":"Missing required information"}

EDIT 2: PHP Code

uploadImage.php

<?php

// report all errors except E_NOTICE
error_reporting(E_ALL & ~E_NOTICE);

// Part 1: Upload File
// Step 1: check data passed to this php file
if (empty($_REQUEST["id"])) {

    $returnArray["message"] = "Missing required information";
    print json_encode($returnArray);
    return;
}

// request user id
$id = htmlentities($_REQUEST["id"]);

// step 2: create a folder for user with id as folder name
$folder = "/Applications/XAMPP/xamppfiles/htdocs/project/image/" . $id;

// if folder doesn't exist
if (!file_exists($folder)) {

    mkdir($folder, 0777, true);

}

// step 3: move uploaded file
$folder = $folder . "/" . basename($_FILES["file"]["name"]);

if (move_uploaded_file($_FILES["file"]["tempname"], $folder)) {
    $returnArray["status"] = "200";
    $returnArray["message"] = "The file has been uploaded successfully.";
} else {
    $returnArray["status"] = "300";
    $returnArray["message"] = "Error while uploading.";
}


// Part 2: Updating image path
// build secure connection

$file = parse_ini_file("../../../project.ini");

// store variable information from ini file in php as variables
$host = trim($file["dbhost"]);
$user = trim($file["dbuser"]);
$pass = trim($file["dbpass"]);
$name = trim($file["dbname"]);

// include access.php to call connect function from access.php file
require ("secure/access.php");
$access = new access($host, $user, $pass, $name);
$access->connect();

// STEP 5: save path to uploaded file in database
$path = "http://localhost/project/image/" . $id . "/ava.jpg";
$access->updateImagePath($path, $id);

// STEP 6: get new user information after updating
$user = $access->selectUserViaID($id);

$returnArray["id"] = $user["id"];
$returnArray["username"] = $user["username"];
$returnArray["fullname"] = $user["fullname"];
$returnArray["email"] = $user["email"];
$returnArray["image"] = $user["image"];

// Step 7. Close Connection
$access->disconnect();

// Step 8. feedback array to app
echo json_encode($returnArray);

?>

Answer 1

With help from @OOper in comments I was able to trace error to syntax error in a function called by my main uploadImage.php file (see main post) and also to the use of "tempname" when I should have used "tmp_name."