Creating and streaming images with Node

Having gone over the main strategies for initiating and diverting streams of data, let's practice the theory by creating a service to stream (aptly named) PNG (Portable Network Graphics) images to a client. This will not be a simple file server, however. The goal is to create PNG data streams by piping the output stream of an ImageMagick convert operation executing in a separate process into the response stream of an HTTP connection, where the converter is translating another stream of SVG (Scalable Vector Graphics) data generated within a virtualized DOM (Document Object Model), existing in the Node runtime. Let's get started.

The full code for this example can be found in your code bundle.

Our goal is to use Node to generate pie charts dynamically on a server based on client requests. A client will specify some data values, and...