ExpressJS Routes Info

This small library tries to help implementing rfc6570 as route path in expressJS. It is far from implementing the whole RFC6570, but is a good starting point to be able to define basic routes this way.

It allows the user to define routes in an ExpressJS application using routers, and enable them to reuse the routes to generate dynamic values. The idea behind this library is to pass and construct the req.baseUrl value statically. This value is only available for the current router at runtime, and reconstructing the path from the generated regexp is quite tedious.

Usage

In your server/app.js:

const routesInfo = require('./routes');

const app = express();

app.use(routesInfo('/something', '/').router);

In your server/routes.js:

const RoutesInfo = require('@quoin/expressjs-routes-info');

const homepageRoutesInfo = require('./homepage').routesInfo;
const mapRoutesInfo = require('./map').routesInfo;

module.exports = (subPath, baseUrl) => {
    const routesInfo = new RoutesInfo(subPath, baseUrl);
    const prefix = `${baseUrl}/${subPath}`;

    routesInfo.use(homepageRoutesInfo('/', prefix));
    routesInfo.use(mapRoutesInfo('/map', prefix));

    return routesInfo;
};

In your server/map/routes.js:

const RoutesInfo = require('@quoin/expressjs-routes-info');

const controllers = require('./controllers');

module.exports = (subPath, baseUrl) => {
    const routesInfo = new RoutesInfo(subPath, baseUrl);

    routesInfo.route('map', '/{id}')
        .get(controllers.index);

    return routesInfo;
};

or you can also use the express notation:

    routesInfo.route('map', '/:id')
        .get(controllers.index);

The route will also accept querystring:

    // Not RFC6570
    routesInfo.route('pageView', '/pageView/{domain}?pv={id}')
        .get(controllers.index);

    // RFC6570
    routesInfo.route('pageView', '/pageView/{domain}{?pv}')
        .get(controllers.index);

The difference between the two is what variable name will be used during the .expand() call. We would agree that the query param should have been id, instead of pv, but this is to demonstrate the options.

You can alternatively pass in an implementations object: (new in 0.1.8)

.route(routeName, routePath, [implementations, [options]])

.route(routeName, routePath)

The basic usage will return the expressJS route instance and all methods can then be added as you would normally do after defining .route().

    routesInfo.route('route-name', '/path/{param}')
        .get(...)
        .post(...)

.route(routeName, routePath, implementations)

Object that is defined as:

    implementations = Object.freeze({
        get: getImplementation,
        post: postImplementation,
        ...
    });

    routesInfo.route('route-name', '/path/{param}', implementations);

and the library will extract all and the HTTP request methods (beside connect), and assign them to the route for that specific method.

.route(routeName, routePath, implementations, options)

    options = {
        allowPatch: 'application/json',
        ...
    };

This signature is just a quick way to add the Allow-Patch header if the patch implementation is defined to all methods.

.expand(routeName, routeParams, [req])

With this new library, you can now generate the URL dynamically:

const RoutesInfo = require('@quoin/expressjs-routes-info');

console.log(RoutesInfo.expand('map', {id: '0xABCDEF'}));
// /something/map/0xABCDEF

When passing req as the optional third argument, the URL should be generated as a full URI (containing the hostname):

console.log(RoutesInfo.expand('map', {id: '0xABCDEF'}, req));
// https://your-host:port/something/map/0xABCDEF

RoutesInfo.staticPath(name, app, baseUrl, urlPath, folderPath)

Add a named static path to the app. Approximatively equivalent to:

    app.use(`${baseUrl}/${urlPath}`, express.static(folderPath));

RoutesInfo.externalUrl(name, url)

Add a route to an external URL. This will not try to add a route to your application.

    > RoutesInfo.externalUrl('hello:world', 'http://external.host/foo/bar/{sub}{?param1,param2}');
    > RoutesInfo.expand('hello:world', { sub: 'foobar', param2:'value2' });
    'http:/external.host/foo/bar/foobar?param2=value2'

This is not intended to support mailto:, so use at your own risk.

Debugging

To enable debugging message, define

DEBUG=Quoin:expressjs-routes-info:*

Reset

This should not be needed for normal operation, but was added to allow testing of code that depends on this library.

const routesInfoCache = require('@quoin/expressjs-routes-info/lib/cache');

describe("", () => {
    beforeEach(() => {
        routesInfoCache.reset();
    });

    afterEach(() => {
        routesInfoCache.reset();
    });
});