hapi-plugin-co.js

/*
**  hapi-plugin-co -- HAPI plugin for Co-Routine handlers
**  Copyright (c) 2016 Ralf S. Engelschall <rse@engelschall.com>
**
**  Permission is hereby granted, free of charge, to any person obtaining
**  a copy of this software and associated documentation files (the
**  "Software"), to deal in the Software without restriction, including
**  without limitation the rights to use, copy, modify, merge, publish,
**  distribute, sublicense, and/or sell copies of the Software, and to
**  permit persons to whom the Software is furnished to do so, subject to
**  the following conditions:
**
**  The above copyright notice and this permission notice shall be included
**  in all copies or substantial portions of the Software.
**
**  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
**  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
**  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
**  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
**  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
**  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
**  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

/*  external dependencies  */
var Boom = require("boom")
var co   = require("co")

/*  internal dependencies  */
var Package = require("./package.json")

/*  the HAPI plugin register function  */
var register = function (server, options, next) {

    /*  perform WebSocket handling on HAPI start  */
    server.ext({ type: "onPreStart", method: function (server, next) {

        /*  iterate over all routes  */
        var connections = server.table()
        connections.forEach(function (connection) {
            connection.table.forEach(function (route) {

                /*  on-the-fly replace plain generator function with regular function
                    which internally uses the generator function as a co-routine  */
                if (   typeof route.settings.handler === "function"
                    && route.settings.handler.constructor.name === "GeneratorFunction") {
                    route.settings.handler = (function (handler) {
                        return function (request, reply) {

                            /*  execute generator function as a co-routine  */
                            co.wrap(handler.bind(this))(request, reply).then(function (result) {
                                /*  convert return values into HTTP replies  */
                                if (result !== undefined)
                                    reply(result)
                            }).catch(function (err) {
                                /*  convert errors into HTTP replies  */
                                if (!(typeof err === "object" && err.isBoom)) {
                                    if (err instanceof Error) {
                                        err = Boom.wrap(err, 500)
                                        request.log([ "error", "uncaught" ], err.message)
                                    }
                                    else if (typeof err === "string") {
                                        err = Boom.create(500, err)
                                        request.log([ "error", "uncaught" ], err)
                                    }
                                    else {
                                        err = Boom.create(500, String(err))
                                        request.log([ "error", "uncaught" ], String(err))
                                    }
                                }
                                reply(err)
                            })
                        }
                    })(route.settings.handler)
                }
            })
        })

        /*  continue processing  */
        next()
    }})

    /*  continue processing  */
    next()
}

/*  provide meta-information as expected by HAPI  */
register.attributes = { pkg: Package }

/*  export register function, wrapped in a plugin object  */
module.exports = { register: register }