PHP Foreach and jQuery - php

Question

I am working on a piece of code that I am wanting to "spice" up with jQuery but I can't think of a way to actually make it work. I am sure its simple, I just need a little advice to get me going.
I am wanting to create a piece of code that makes an Ajax request out to start a big loop that will download files and then upload them to an S3 bucket of mine. The place where I am stuck is I am wanting to send back a request back to the browser everytime a file is uploaded and output a string of text to the screen upon completion.
I don't have any of the frontend code working... just trying to get my head wrapped around the logic first... any ideas?
PHP Backend Code:
<?php
public function photos($city) {
if(isset($city))
$this->city_name = "{$city}";
// grab data array from Dropbox folder
$postcard_assets = $this->conn->getPostcardDirContent("{$this->city_name}", "Photos", TRUE);
$data = array();
foreach($postcard_assets['contents'] as $asset) {
//only grab contents in root folder... do not traverse into sub folders && make sure the folder is not empty
if(!$asset['is_dir'] && $asset['bytes'] > 0) {
// get information on file
$file = pathinfo($asset['path']);
// download file from Dropbox
$original_file = $this->conn->downloadFile(str_replace(" ", "%20", $asset['path']));
// create file name
$file_name = $this->cleanFileName($file['basename']);
// write photo to TMP_DIR ("/tmp/photos/") for manipulation
$fh = fopen(self::TMP_DIR . $file_name, 'w');
fwrite($fh, $original_file);
fclose($fh);
// Resize photo
$this->resize_photo($file_name);
// hash file name
$raw_file = sha1($file_name);
// create S3 hashed name
$s3_file_name = "1_{$raw_file}.{$file['extension']}";
// Upload manipulated file to S3
$this->s3->putObject($s3_file_name, file_get_contents(self::TMP_DIR . $file_name), $this->photo_s3_bucket, 'public-read');
// check to see if file exists in S3 bucket
$s3_check = $this->s3->getObjectInfo($s3_file_name, $this->photo_s3_bucket);
// if the file uploaded successully to S3, load into DB
if($s3_check['content-length'] > 0) {
$data['src'] = $s3_file_name;
$data['width'] = $this->width;
$data['height'] = $this->height;
Photo::create_postcard_photo($data, "{$this->city_name}");
// Now that the photo has been uploaded to S3 and saved in the DB, remove local file for cleanup
unlink(self::TMP_DIR . $file_name);
echo "{$file_name} uploaded to S3 and resized!<br />";
}
}
}
// after loop is complete, kill script or nasty PHP header warnings will appear
exit();
}
?>

Answer 1

The main problem is that with PHP, the output is buffered so it won't return a line at a time. You can try and force the flush but it's not always reliable.
You could add an entry to the DB for each file that is exchanged and create a seperate API to get the details of what has completed.
Generally, Jquery will wait till the request has finished before it allows you to manipulate data from a HTTP request.