使用php从给定的Google图表api URL下载图像文件

Question

i want to download image returned by this url using a link like <a href="">Download</a> and on click of this link download box should appear so user can save image to his/her system. here is the url that return image

http://chart.apis.google.com/chart?chs=300x300&cht=qr&chld=L|0&chl=http%253A%252F%252Fnetcane.com%252Fprojects%252Fyourl%252F3

i don't want to save the image to server is it possible ?

Answer 1

Original Question

You can stream or proxy the file to your users by setting up a simple PHP download script on your server. When user hits the download.php script below it will set the correct headers so that their browsers asks them to save a download. It will then stream the chart image from google to the users browser.

In your HTML:

<a href="download.php">Download</a>

In download.php:

header('Content-Type: image/png');
header('Content-Disposition: attachment; filename="chart.png"');
$image = file_get_contents('http://chart.apis.google.com/chart?chs=300x300&cht=qr&chld=L|0&chl=http%253A%252F%252Fnetcane.com%252Fprojects%252Fyourl%252F3');
header('Content-Length: ' . strlen($image));
echo $image;

Passing in dynamically generated chart API URLs

In your HTML:

<?php
$url = 'http://chart.apis.google.com/chart?my-generated-chart-api-url';
<a href="download.php?url=<?php echo urlencode($url); ?>">Download</a>

In download.php:

$url = '';
if(array_key_exists('url', $_GET)
   and filter_var($_GET['url'], FILTER_VALIDATE_URL)) {
     $url = $_GET['url'];
}
header('Content-Type: image/png');
header('Content-Disposition: attachment; filename="chart.png"');
$image = file_get_contents($url);
header('Content-Length: ' . strlen($image));
echo $image;

Answer 2

No, not really. Since the image is generated at chart.apis.google.com , and you don't have control over that server, you can't make it send the Content-Disposition header with that image; therefore, browsers will display that image.

What you technically could do (but I'm not sure if Google's ToS allows it, better check), is to link to your server, which will proxy the download and add the Content-Disposition: attachment header.

Answer 3

I believe you will not be able to do that. The closest thing would be to dynamically get the image data using PHP and then serving it with the header Content-Disposition: attachment; filename=qr.png

<?php

$img_data = file_get_contents("http://chart.apis.google.com/chart?chs=300x300&cht=qr&chld=L|0&chl=http%253A%252F%252Fnetcane.com%252Fprojects%252Fyourl%252F3");
header("Content-Type: image/png");
header("Content-Length: " . strlen($img_data));
header("Content-Disposition: attachment; filename=qr.png");
print $img_data;

?>

Code is untested, but I think you get the gist of it. Hope its what you're looking for.