gpii-express

What is this?

This package provides a series of Fluid components that encapsulate the main features of Express. Express is a node-based server framework written in Javascript.

In addition to Express itself, this package provides:

1. Wrappers for common routers and middleware provided with Express.
2. Base grades that can be used in writing your own routers and middleware.

Why would I need it?

This module allows you to wire together fluid components to serve up APIs and static content. Simple server-side use cases can be implemented purely by configuring the components provided here.

How is this different from Kettle?

In the long term, the two modules will likely evolve closer to each other, but in the short term, there are few key differences.

Kettle is a server side framework written entirely as a series of Fluid components, and used extensively within the GPII. Kettle better serves use cases that don't involve a markup-based UI, and provides deeper options for replacing the internals of the server. It also provides support for WebSockets.

The gpii.express module is a wrapper for Express, and only for Express. It does not do anything that Express cannot, such as communicating using WebSockets. However, as it is based on the idiom of a newer version of express, it provides the router concept introduced in Express 4.x, which Kettle does not have. It is better suited for use cases where support for complex routing and rendering of complex markup-based interfaces (as provided via gpii-handlebars) is required.

How do I use it?

To use this module, you will need to instantiate an instance of gpii.express itself (or something that extends it), and wire in at least one gpii.express.middleware module. The most basic example (serving static content) should look something like:

fluid.defaults("my.namespaced.grade", {
    gradeNames: ["gpii.express"],
    port:    8080,
    components: {
        staticRouter: {
            type: "gpii.express.router.static",
            options: {
                path:    "/",
                content: "%gpii-express/tests/html"
            }
        }
    }
});

See the documentation for the gpii.express grade for a full list of configuration options. This example configures a "static" router that is designed to serve up filesystem content (see the middleware documentation for more details).

For more information about the grades included in this package and how to use them together, take a look at the documentation in this package.