Send Raw Data from PHP Server API to Swift client API - php

Question

My goal is to store and retrieve raw data from a PHP script and client Swift code using HTTP POST. I am using MySQL database storing MEDIUMBLOB data.
I successfully sent the data from Swift and stored it into database.
Here is my working code used to store the data (I removed the WHERE clause to simplify), I can see the stored raw data using PHPMyAdmin (e.g. [BLOB - 345.6 KiB] which is the same size as client code data size) :
<?php
//...
$file = $_FILES['file']['tmp_name'];
$file_data = file_get_contents($file);
$file_info = finfo_open(FILEINFO_MIME_TYPE);
$file_type = finfo_file($file_info, $file);
$file_size = filesize($file);
$worldMap1 = $file_data;
$query = $query = "INSERT INTO " . $this->table_name . " SET worldMap1=:worldMap1";
//...
?>
Client Swift code (request structure) :
let boundary = generateBoundaryString()
var request = URLRequest(url: requestedUrl)
request.httpMethod = POSTMETHOD
request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
request.httpBody = createBodyWithParametersForData(
parameters: dataBody,
filePathKey: "file",
imageDataKey: data,
boundary: boundary
)
private func createBodyWithParametersForData(parameters: [String: Any]?, filePathKey: String?, imageDataKey: Data, boundary: String) -> Data {
var body = Data();
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 = "file"
let mimetype = "application/octet-stream"
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)
body.appendString(string: "\r\n")
body.appendString(string: "--\(boundary)--\r\n")
return body
}
Now I simply want to send the data back to client Swift code (non working code) :
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");
// Fetch the record:
$query = "SELECT worldMap1 FROM " . $this->table_name . "";
// prepare query
$stmt = $db->prepare($query);
//...
// execute query
$stmt->execute();
if ($stmt->rowCount() == 1) {
// Fetch the record into a variable:
$row = $stmt->fetch(PDO::FETCH_ASSOC);
$file_size = filesize($row["worldMap1"]);
// Send the content information:
header("Content-Type: application/octet-stream\n");
header("Content-Disposition: attachment; filename=\"file\"\n");
header("Content-Length: {$file_size}\n");
// Send the file:
echo $row["worldMap1"];
}
// Omit the closing PHP tag to avoid tainting the downloaded file
On client side, I either receive 0 byte data or timeout error codes.
I also tried to hardcode the Content-Length value e.g. 1000.
I do not see any clear documentation on how to send raw data from PHP code.
Here is the only useful information I found and used to store the data : http://www.peachpit.com/articles/article.aspx?p=1967015&seqNum=4

Answer 1

Generally, files are stored in a directory and not in a database.
It looks like the problem is most likely with your Content-Type: application/octet-stream\n header. I don't think it's enough to just tell the browser hey, I'm expecting an octet-stream.
In order for your browser to recognize this as an attachment properly I would change the header to indicate the actual type of file you are dealing with so it knows how to interpret the file.
Like so:
header('Content-Type: ' . $type);
Here are a list of accepted MIME-TYPES
You are also over-writing your your content type header from the "required" application/json to the octet-stream. I would probably not send out the aplication/json header. Even though I believe it would be over-written by the latter.
Make sure you send your headers out before ANYTHING is outputted by the script. Even an unknown white space can cause you problems.
I also do not see the need for the \n in you header.
I would also consider using single quotes instead of double quotes as your likely to make mistakes escaping your double quotes for your file name.
Hope that helps.
Again, if it were me I would not do this. I would upload all the files to a directory not a db.