swenedo swenedo - 4 months ago 24
PHP Question

Download file from server with angular $http.get

I am trying to trigger a file download when a user clicks on a "Download PDF" button. A call is made to the API which makes a few checks, and then returns the file. I don't want the file to open in the browser. I have read a lot of stackoverflow-questions about how to do this, but can't get it to work. I get the file content as text back, but the browser doesn't save the file, nor gives me the choice to save it as a file.

This is what I have.

HTML

<button ng-click="apiDownload()">Download PDF</button>


AngularJS controller

$scope.apiDownload = function(){
var config = {
method: 'GET',
url: "/api/download",
headers: {
'Accept': 'application/pdf'
}
};
$http(config)
.success(function(res){
console.log(res);
})
.error(function(res){});
};


PHP API (mostly from here)

function apiDownloadFile() {
$file_name = "download/test.pdf";
$abs_file_name = realpath(dirname(__FILE__)).'/'.$file_name;
if(is_file($abs_file_name) && file_exists($abs_file_name)) {

// required for IE
if(ini_get('zlib.output_compression')) { ini_set('zlib.output_compression', 'Off'); }

// get the file mime type using the file extension
switch(strtolower(substr(strrchr($file_name, '.'), 1))) {
case 'pdf': $mime = 'application/pdf'; break;
case 'zip': $mime = 'application/zip'; break;
case 'jpeg':
case 'jpg': $mime = 'image/jpg'; break;
default: $mime = 'application/force-download';
}
header('Pragma: public'); // required
header('Expires: 0'); // no cache
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Last-Modified: '.gmdate ('D, d M Y H:i:s', filemtime ($abs_file_name)).' GMT');
header('Cache-Control: private',false);
header('Content-Type: '.$mime);
header('Content-Disposition: attachment; filename='.basename($abs_file_name));
header('Content-Transfer-Encoding: binary');
header('Content-Length: '.filesize($abs_file_name)); // provide file size
header('Connection: close');
readfile($abs_file_name); // push it out
exit();
}

}


I see these headers in chrome developer tools:

Request Headers

GET /api/download HTTP/1.1
Host: sa.dev
Connection: keep-alive
Cache-Control: no-cache
Pragma: no-cache
Accept: application/pdf
If-Modified-Since: 0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.89 Safari/537.36
Referer: https://sa.dev/insights
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8,da;q=0.6,sv;q=0.4,no;q=0.2,nb;q=0.2
Cookie: ...


Response Headers

HTTP/1.1 200 OK
Date: Mon, 16 Mar 2015 14:27:08 GMT
Server: Apache/2.4.9 (Unix) PHP/5.6.5 OpenSSL/0.9.8zc
X-Powered-By: PHP/5.6.5
Pragma: public
Expires: 0
Cache-Control: must-revalidate, post-check=0, pre-check=0
Last-Modified: Mon, 16 Mar 2015 09:04:06 GMT
Cache-Control: private
Content-Disposition: attachment; filename=test.pdf
Content-Transfer-Encoding: binary
Content-Length: 5501633
Connection: close
Content-Type: application/pdf

Answer

I solved this by using John Culviner's jQuery.fileDownload library (see this SO-answer).

When using jQuery.fileDownload I had to do add two things to my code.

  1. Set a cookie

    • In PHP: setcookie('fileDownload', "true", NULL, '/');
    • Set-Cookie header will look like this: Set-Cookie: fileDownload=true; path=/
  2. Call $.fileDownload('/api/download'); from js. And remove use of angular $http.

See this blog for more information of how to use jQuery.fileDownload.

If someone have a solution to do this without using a jQuery library, feel free to post it as an answer.