[Hapi.js] Friendly error pages with extension events

hapi automatically responds with JSON for any error passed to a route's reply()method. But what if your application needs errors rendered in HTML? This lesson shows how to implement friendly HTML error messages using hapi extension events.

const Hapi = require( 'hapi' )
const Boom = require( 'boom' )
const server = new Hapi.Server()
server.connection( { port: 8000 } )


server.register(require('vision'), function(request, reply){
    server.views({
        engines: { hbs: require('handlebars') },
        relativeTo: __dirname,
        path: 'views'
    });

    server.ext('onPreResponse', function(request, reply){
        var resp = request.response;
        // if there is an error
        if (resp.isBoom) {
            return reply.view('error', resp.output.payload)
                        // change the status code
                        .code(resp.output.statusCode);
        }
        reply.continue()
    })
})


server.start( function (err) {
    if (err) {
        throw err;
    }
    console.log( 'Started at:', server.info.uri )
} );