I'm using Dropzone.js to take files of various types (including images and non-images, like a PDF), and upload them in 1mb chunks to our server. I'm then attempting to concatenate the files with PHP and later upload them to our company's FileMaker database.
So far I've been able to get the files to upload in the chunks, as they should. I store them all in a temporary "uploads" folder with the same "codename," with "-INDEX#" appended to the end of each name (INDEX# being the chunk # being uploaded, as passed by Dropzone).
I've isolated the failure to the portion of the PHP that loops through the already uploaded chunks to grab the content. Specifically, when I go to fetch the content, I attempt to save the file path of the chunk to a variable by using PHP's "realpath" to both get the absolute path, and also serve as a true/false check of the file's existence. Without fail, PHP is unable to "see" the file.
I'm not an expert at folder permissions, so there's a strong chance it could be related to that and that I just don't know how to deal with it. You'll see that I did attempt a chmod at the top of the PHP on the uploads/ directory.
I've included only the PHP code below, and none of the javascript. I'm not sure that the JS is relevant since it's apparently working just fine with the actual chunk uploads.
The PHP file below is in the same directory as the uploads/ folder where the chunks are to end up.
<?php
header("Cache-Control: no-store, no-cache, must-revalidate, max-age=0");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
/* ========================================
VARIABLES
======================================== */
// chunk variables
$fileId = $_POST['dzuuid'];
$chunkIndex = $_POST['dzchunkindex'] + 1;
$chunkTotal = $_POST['dztotalchunkcount'];
// file path variables
$ds = DIRECTORY_SEPARATOR;
$targetPath = dirname( __FILE__ ) . "{$ds}uploads{$ds}";
$fileType = strtolower(pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION));
$fileSize = $_FILES["file"]["size"];
$filename = "{$fileId}-{$chunkIndex}.{$fileType}";
$targetFile = $targetPath . $filename;
// change directory permissions
chmod(realpath($targetPath), 0777);
/* ========================================
DEPENDENCY FUNCTIONS
======================================== */
$returnResponse = function ($info = null, $filelink = null, $status = "error") {
die (json_encode( array(
"status" => $status,
"info" => $info,
"file_link" => $filelink
)));
};
/* ========================================
VALIDATION CHECKS
======================================== */
// I removed all the validation code here. They just prevent upload, so assume the upload is going through.
/* ========================================
CHUNK UPLOAD
======================================== */
move_uploaded_file($_FILES['file']['tmp_name'], $targetFile);
// Be sure that the file has been uploaded
if ( !file_exists($targetFile) ) $returnResponse("An error occurred and we couldn't upload the requested file.");
/* ========================================
FINAL UPLOAD CONDITIONAL
======================================== */
if ( $chunkIndex == $chunkTotal ) {
// ===== concatenate uploaded files =====
// set emtpy string for file content concatonation
$file_content = "";
// loop through temp files and grab the content
for ($i = 1; $i <= $chunkTotal; $i++) {
// target temp file
$temp_file_path = realpath("{$targetPath}{$fileId}-{$i}.{$fileType}") or $returnResponse("Your chunk was lost mid-upload.");
// ^^^^^^^ this is where the failure is occurring, $i = 1, so first iteration
// copy chunk...you'll see a bunch of methods included below that I've tried, but the simplest one is method 3, so I've tested mostly there
// method 1
/*$temp_file = fopen($temp_file_path, "rb") or $returnResponse("The server cannot open your chunks");
$chunk = base64_encode(fread($temp_file, $fileSize));
fclose($temp_file);
// method 2
$chunk = base64_encode(stream_get_contents($temp_file_path, $fileSize));*/
// method 3
$chunk = base64_encode(file_get_contents($temp_file_path));
// check chunk content
if ( empty($chunk) ) $returnResponse("Chunks are uploading as empty strings.");
// add chunk to main file
$file_content .= $chunk;
// delete chunk
unlink($temp_file_path);
if ( file_exists($temp_file_path) ) $returnResponse("Your temp files could not be deleted.");
continue;
}
// create and write concatonated chunk to the main file
file_put_contents("{$targetPath}{$fileId}.{$fileType}", base64_decode($file_content));
// other method of adding contents to new file below, but the one above seemed simpler
//$final = fopen("{$target_file}.{$fileType}", 'ab');
//fwrite($final, base64_decode($file_content));
//fclose($final);
// create new FileMaker code removed here, irrelevant
// run FileMaker script to populate container field with concatenated file code removed here, irrelevant
// somewhere in the code above, if everything succeeds, I unlink the concatenated file so that it's not cluttering my "uploads" folder, but I never get this far
} else {
$returnResponse(null, null, "success");
}
