一旦在node.js Web服务器上生成图像（使用express），显示图像的最简单方法是什么？

Question

I created a small web server in node.js using the express 4 framework. When a user submits an image file from the main web page, it uploads to the server via the multer middleware, is processed by a python script, and then the resulting image is saved on the server.

What is the simplest way I can deliver the finished, processed image back to the client once it is done and saved on the server?

Answer 1

Method 1 : Streaming from nodejs

If you mean streaming the resulting file to the client, you could do something like this

    var fileStream = fs.createReadStream(filename);
    fileStream.on('error', function (error) {
        response.writeHead(404, { "Content-Type": mimetype});
        response.end("file not found");
    });
    fileStream.on('end', function() {
        console.log('sent file ' + filename);
        response.end("");
    });
    fileStream.pipe(response);

as mimetype, use one from here http://www.sitepoint.com/web-foundations/mime-types-complete-list/

Method 2 : Leveraging to public files

But using express, I think the best way is that the resulting image is saved into express' "public" folder, and that is served right to the client.

<img src="server.com/public/generated.jpg">

I recommend this method specially because when using nodejs/express with a reverse proxy (nginx or similar), you can serve the public folder directly to the client, without passing the request through nodejs stack.

See this for more info http://expressjs.com/starter/static-files.html