combi-server

combi-server

A lightweight combined http/ws API server framework built to be extended

combi-server is a framework for easily creating Node.js API servers, with a focus on serving responses with JSON to emphasise a disconnect between client and server functionality. It comes bundled with a mono-roomed WebSocket server that executes based on typed requests.

Installation

As with all node modules, you can install combi-server from NPM with the npm install --save combi-server command. It can then be used in your Node.js servers with var http = require("combi-server");. If you don't have access to NPM, simply download the latest release from GitHub and drop the contents (as reflected in the GitHub file viewer) into this folder relative to the root of you Node.js project: /node_modules/combi-server/.

Using combi-server

There are three stages to creating a combi-server server. Note that setting the port that the server will be listening to is done when initialising the server, not when calling the listen function.

Initialising The Server

Requiring the combi-server module returns a function. Calling this function with a configuration object will give you a fully configured server; the configuration object is a standard javascript object with one required and several optional properties. The server integrates the options into the server object, allowing end users to set arbitrary methods that can be called on the resultant server object. Optional properties that are not defined will have certain default behaviours but will not be set as such.

Required:

• port: The port number of the local machine to listen on

Optional:

• appname: The name to show up in the server logs on boot. Otherwise doesn't do much by default. (Default Behaviour: undefined)
• useAnsi: Use ansi colour codes in the server logs. (Default Behaviour: false)
• websocket: An object with configuration properties for the websocket server. (Default Behaviour: WS server not created)

Websocket:

• enabled: Whether or not the WS server will be created (Default Behaviour: false)

Options with other names will be added to the server object, allowing for custom functions to be added, but will be overwritten by default methods and properties with the same name (options integration happens before internal config). The following properties and methods are set after options are added (will overwrite custom properties): ws, wss, use, static, next, enhanceRequest, enhanceResponse, listen, server.

In addition to this, the following middleware are bundled with combi-server:

• Static File Server: Serves files from the specified path as if they were in the root directory, enabled by calling http.static(path); in place of http.use. For example, this would serve all files from the /public directory of the server: http.static(path.join(__dirname, 'public'));. A request to example.com/images/kitten.png would serve the file /public/images/kitten.png.

Adding Middleware

HTTP Middleware

Without adding any other functions, the http server will spit back a 404 for every request. In order to do anything, you'll need to add middleware functions; by using the http.use(fn) function you can add arbitrary functions to be executed in order. Each function added will be provided with the req, res, and next parameters and must return either an object that conforms to the Promises/A spec and has a .spread method (for async middleware) or null (returning anything else is also the same as returning null).

REQ

TODO: Add info about enhanced req

• req.ip

RES

TODO: Add info about enhanced res

• res.json(obj)
• res.error(status, obj)
• res.send(status, data[, headers])
• res.sendFile(filestream, statObj)
• res.sendFileStream(req, path)
• res.setHeader(key, val)
• res.setHeaders(headers)
• res.finish()
• res.finished
• res.headers

WS Middleware

The raw websocket server can be accessed via the http.wss property (assigned during the http.listen() call). In order to access the combi-server WS middleware API, you need to call methods on the http.ws object. http.ws.do(type, fn) is the websocket version of http.use(fn); it requires a type parameter that corresponds to the custom websocket event that you want the function to listen for, as well as a callback function that will recieve the connection and data parameters that correspond to the enhanced connection object of the client and the payload of the request respectively.

The type parameter is a string identifying the request type to handle. This can be literally anything that you need for your API (bob, secrets and breakThisThing are all fine, if somewhat questionable). It can also optionally contain one of three data types in order to define a conversion for the payload. By setting a data type, the data parameter provided to the callback will be in that format. If none is provided, it will be a string. Data types are defined with a colon followed by the type; bob:string, bob:number and bob:json are all valid type parameters (N.B Bare arrays are valid JSON, so use the json type for those).

Connection

TODO: Add info about enhanced connection

• conn.sendJson(obj)
• conn._id

Listening To A Port

In order to recieve a request, the server needs to listen to a port. While the port is defined when the combi-server instance is created, the server won't listen to the port until the http.listen() function is called. This allows all the middleware and programatic configuration to occur before requests start coming in. Simply call the listen function and you're golden.