How to Implement Resumable Download in Silex - symfony

In silex I can do this to force-download a file:
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\ResponseHeaderBag;
$app = new Silex\Application();
// Url can be http://pathtomysilexapp.com/download
$app->get('/download', function (Request $request) use ($app) {
$file = '/path/to/download.zip';
if( !file_exists($file) ){
return new Response('File not found.', 404);
}
return $app->sendFile($file)->setContentDisposition(ResponseHeaderBag::DISPOSITION_ATTACHMENT, 'download.zip');
});
$app->run();
This works well for smaller files. However my use case requires downloading a big that can be paused/resumed by a download manager.
There is an example about file streaming but it doesn't seem to be what I am looking for. Has somebody done this before? I could just use the answer from here and be done with it. But it would be nice if there is a silexy way of doing this.

Implementing it is quite trivial if you have a the file on the drive. It is like paginating records from a table.
Read the headers, open the file, seek to the desired position and read the the size requested.
You only need to know a little bit about the headers from the request & response.
Does the server accept ranges:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests
HTTP 206 status for content ranges:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/206
Info about the content range headers:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Range

Related

How to return binary data from custom wordpress rest api endpoint

I am writing a custom endpoint for a REST api in wordpress, following the guide here: https://developer.wordpress.org/rest-api/extending-the-rest-api/adding-custom-endpoints/
I am able to write a endpoint that returns json data. But how can I write an endpoint that returns binary data (pdf, png, and similar)?
My restpoint function returns a WP_REST_Response (or WP_Error in case of error).
But I do not see what I should return if I want to responde with binary data.
Late to the party, but I feel the accepted answer does not really answer the question, and Google found this question when I searched for the same solution, so here is how I eventually solved the same problem (i.e. avoiding to use WP_REST_Response and killing the PHP script before WP tried to send anything else other than my binary data).
function download(WP_REST_Request $request) {
$dir = $request->get_param("dir");
// The following is for security, but my implementation is out
// of scope for this answer. You should either skip this line if
// you trust your client, or implement it the way you need it.
$dir = sanitize_path($dir);
$file = $request->get_param("file");
// See above...
$file = sanitize_path($file);
$sandbox = "/some/path/with/shared/files";
// full path to the file
$path = $sandbox.$dir.$file;
$name = basename($path);
// get the file mime type
$finfo = finfo_open(FILEINFO_MIME_TYPE);
$mime_type = finfo_file($finfo, $path);
// tell the browser what it's about to receive
header("Content-Disposition: attachment; filename=$name;");
header("Content-Type: $mime_type");
header("Content-Description: File Transfer");
header("Content-Transfer-Encoding: binary");
header('Content-Length: ' . filesize($path));
header("Cache-Control: no-cache private");
// stream the file without loading it into RAM completely
$fp = fopen($path, 'rb');
fpassthru($fp);
// kill WP
exit;
}
I would look at something called DOMPDF. In short, it streams any HTML DOM straight to the browser.
We use it to generate live copies of invoices straight from the woo admin, generate brochures based on $wp_query results etc. Anything that can be rendered by a browser can be streamed via DOMPDF.

Connection to this site is not Fully Secure

I have a website on which users can write blog posts. I'm using stackoverflow pagedown editor to allow users to add content & also the images by inserting their link.
But the problem is that in case a user inserts a link starting with http:// such as http://example.com/image.jpg, browser shows a warning saying,
Your Connection to this site is not Fully Secure.
Attackers might be able to see the images you are looking at
& trick you by modifying them
I was wondering how can we force the browser to use the https:// version of site only from which image is being inserted, especially when user inserts a link starting with http://?
Or is there any other solution of this issue?
image
unfortunately, browser expect to have all loaded ressources provided over ssl. On your case you have no choice than self store all images or create or proxy request from http to https. But i am not sure if is really safe to do this way.
for exemple you can do something like this :
i assume code is php, and over https
<?php
define('CHUNK_SIZE', 1024*1024); // Size (in bytes) of tiles chunk
// Read a file and display its content chunk by chunk
function readfile_chunked($filename, $retbytes = TRUE) {
$buffer = '';
$cnt = 0;
$handle = fopen($filename, 'rb');
if ($handle === false) {
return false;
}
while (!feof($handle)) {
$buffer = fread($handle, CHUNK_SIZE);
echo $buffer;
ob_flush();
flush();
if ($retbytes) {
$cnt += strlen($buffer);
}
}
$status = fclose($handle);
if ($retbytes && $status) {
return $cnt; // return num. bytes delivered like readfile() does.
}
return $status;
}
$filename = 'http://domain.ltd/path/to/image.jpeg';
$mimetype = 'image/jpeg';
header('Content-Type: '.$mimetype );
readfile_chunked($filename);
Credit for code sample
_ UPDATE 1 _
Alternate solution to proxify steamed downloaded file in Python
_ UPDATE 2 _
On following code, you can stream data from remote server to your front-end client, if your Django application is over https, content will be deliver correctly.
Goal is to read by group of 1024 bits your original images, them stream each group to your browser. This approch avoid timeout issue when you try to load heavy image.
I recommand you to add another layer to have local cache instead to download -> proxy on each request.
import requests
# have this function in file where you keep your util functions
def url2yield(url, chunksize=1024):
s = requests.Session()
# Note: here i enabled the streaming
response = s.get(url, stream=True)
chunk = True
while chunk :
chunk = response.raw.read(chunksize)
if not chunk:
break
yield chunk
# Then creation your view using StreamingHttpResponse
def get_image(request, img_id):
img_url = "domain.ltd/lorem.jpg"
return StreamingHttpResponse(url2yield(img_url), content_type="image/jpeg")

Return an image from a controller action in symfony

I need to access an image by providing its name in the url path, i tried to use this code but the image is not showing
/**
*
* #Route("images/{imgname}",name="workflow_image")
*/
public function WorkflowImageAction(Request $request,$imgname){
$filepath = $this->get('kernel')->getRootDir().'/../web/images/workflow/'.$imgname;
$file = readfile($filepath);
$headers = array(
'Content-Type' => 'image/png',
'Content-Disposition' => 'inline; filename="'.$file.'"');
return $file;
}
if you are serving a static file, you can use a BinaryFileResponse:
use Symfony\Component\HttpFoundation\BinaryFileResponse;
$file = 'path/to/file.txt';
$response = new BinaryFileResponse($file);
return $response;
More info about Serving Files in Symfony2 in the doc.
Hope this help
Are you sure, it's a good idea to share image through php?
You can write some rules for folder web/image/workflow in your server (nginx or apache).
Share them through php is bad idea.
Nginx/apache can do it very fast, not using RAM (php read full image in RAM).
Also, nginx/apache can cache this image.
All the answers here are outdated.
I would suggest not using BinaryFileResponse or using file_get_contents since they would read the whole file and place it in your memory.
Please use StreamedResponse provided at Symfony\Component\HttpFoundation\StreamedResponse.
$imageFilePath = dirname(__FILE__)."/../../var/tmp/bean.jpg";
$streamedResponse = new StreamedResponse();
$streamedResponse->headers->set("Content-Type", 'image/png');
$streamedResponse->headers->set("Content-Length", filesize($imageFilePath));
$streamedResponse->setCallback(function() use ($imageFilePath) {
readfile($imageFilePath);
});
return $streamedResponse;

Symfony2 Templating without request

I'm trying to send an email from a ContainerAwareCommand in Symfony2. But I get this exception when the email template is render by:
$body = $this->templating->render($template, $data);
Exception:
("You cannot create a service ("templating.helper.assets") of an inactive scope ("request").")
I found in github that this helper need the request object. Anybody knows how can I to instance the Request object?
You need to set the container into the right scope and give it a (fake) request. In most cases this will be enough:
//before you render template add bellow code
$this->getContainer()->enterScope('request');
$this->getContainer()->set('request', new Request(), 'request');
The full story is here. If you want to know the details read this issue on github.
The problem arises because you use asset() function in your template.
By default, asset() relies on Request service to generate urls to your assets (it needs to know what is the base path to you web site or what is the domain name if you use absolute asset urls, for example).
But when you run your application from command line there is no Request.
One way to fix this it to explicitely define base urls to your assets in config.yml like this:
framework:
templating:
assets_base_urls: { http: ["http://yoursite.com"], ssl: ["http://yoursite.com"] }
It is important to define both http and ssl, because if you omit one of them asset() will still depend on Request service.
The (possible) downside is that all urls to assets will now be absolute.
Since you don't have a request, you need to call the templating service directly like this:
$this->container->get('templating')->render($template, $data);
Following BetaRide's answer put me on the right track but that wasn't sufficient. Then it was complaining: "Unable to generate a URL for the named route "" as such route does not exist."
To create a valid request I've modified it to request the root of the project like so:
$request = new Request();
$request->create('/');
$this->container->enterScope('request');
$this->container->set('request', $request, 'request');
You might need to call a different route (secured root?), root worked for me just fine.
Symfony2 Docs
Bonus addition:
I had to do so much templating/routing in cli through Symfony2 commands that I've updated the initializeContainer() method in AppKernel. It creates a route to the root of the site, sets the router context and fakes a user login:
protected function initializeContainer()
{
parent::initializeContainer();
if (PHP_SAPI == 'cli') {
$container = $this->getContainer();
/**
* Fake request to home page for cli router.
* Need to set router base url to request uri because when request object
* is created it perceives the "/portal" part as path info only, not base
* url and thus router will not include it in the generated url's.
*/
$request = Request::create($container->getParameter('domain'));
$container->enterScope('request');
$container->set('request', $request, 'request');
$context = new RequestContext();
$context->fromRequest($request);
$container->get('router')->setContext($context);
$container->get('router')->getContext()->setBaseUrl($request->getRequestUri());
/**
* Fake admin user login for cli. Try database read,
* gracefully print error message if failed and continue.
* Continue mainly for doctrine:fixture:load when db still empty.
*/
try {
$user = $container->get('fos_user.user_manager')->findUserByUsername('admin');
if ($user !== null) {
$token = $token = new UsernamePasswordToken($user, null, 'main', $user->getRoles());
$this->getContainer()->get('security.token_storage')->setToken($token);
}
} catch (\Exception $e) {
echo "Fake Admin user login failed.\n";
}
}
}
You might not need the last $container->get('router')->getContext()->setBaseUrl($request->getRequestUri()); part, but I had to do it because my site root was at domain.com/siteroot/ and the router was stripping /siteroot/ away for url generation.

Routing in Silex/Symfony. Providing a default route

I'm attempting to do something using Silex (which uses the Symfony routing component - so the answer may be applicable to Symfony as well)
I am adding Silex to a legacy application to provide routing but I need to respect the existing applications default implementation for loading files (which is simply to load the file from the file system form the URL specified).
edit: for clarification:
Existing file is loaded from the file system, as an include within an parent template, after a series of bootstrapping calls have been made.
What I'm finding is that in the absence of a defined route to match the legacy pages, Silex is throwing an exception.
I really need a way to provide a default (fallback) mechanism for handling those legacy pages - but my pattern has to match the entire url (not just one fragment).
Is this possible?
// Include Silex for routing
require_once(CLASS_PATH . 'Silex/silex.phar');
// Init Silex
$app = new Silex\Application();
// route for new code
// matches for new restful interface (like /category/add/mynewcategory)
$app->match('/category/{action}/{name}/', function($action, $name){
//do RESTFUL things
});
// route for legacy code (If I leave this out then Silex
// throws an exception beacuse it hasn't matched any routes
$app->match('{match_the_entire_url_including_slashes}', function($match_the_entire_url_including_slashes){
//do legacy stuff
});
$app->run();
This must be a common use case. I'm trying to provide a way to have a RESTFUL interface alongside legacy code (load /myfolder/mysubfolder/my_php_script.php)
I found the answer within the symfony cookbook...
http://symfony.com/doc/2.0/cookbook/routing/slash_in_parameter.html
$app->match('{url}', function($url){
//do legacy stuff
})->assert('url', '.+');
You can use the error handling, with something like that :
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\HttpException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
$app->error(function (\Exception $e) use ($app) {
if ($e instanceof NotFoundHttpException) {
return new Response('The requested page could not be found. '.$app['request']->getRequestUri(), 404);
}
$code = ($e instanceof HttpException) ? $e->getStatusCode() : 500;
return new Response('We are sorry, but something went terribly wrong.', $code);
});

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