deliver-or-else

This npm module is used to deliver local files automatically to the client depending on the URL. If no file can be located in the local file system, it is possible (through the use of a Promise) to provide some other logic.

Installation

$ npm install deliver-or-else

Usage

When requiring deliver-or-else, you are given a constructor function:

const Deliver = require('deliver-or-else')

The Deliver constructor function takes in one parameter (which is required), denoting the path to the local file system. Only the files in the path you give in will be available to the end users (the browser clients).

Given that, we can dedicate a single directory (such as the conventional public/) to be the one browsers can access:

const path = require('path')
 
// It is up to you to resolve the document root directory
let deliver = new Deliver(path.join(__dirname, 'public'))

Serving Files

Now that we have a Deliver instance, we can use it to automatically deliver files. The directory structure for our files, currently looks like this:

public/
    index.html
    test.css
    test.jpeg

Now to the server:

const http = require('http')
 
let server = http.createServer((req, res) => {
    /**
     * The `deliver` method returns a `Promise`, which in turn can be used to 
     * catch any errors (such as a 404). We could also provide a `then` clause 
     * for when it works successfully and a file has been delivered.
     */
    deliver.deliver(req, res).catch((err) => {
        // The err contains information regarding how the `fs.readFile` failed
        
        res.statusCode = 404
        res.setHeader('Content-Type', 'text/plain')
        res.end('404, no such file.')
    })
})
 
server.listen(80, '127.0.0.1', function () {
    console.log('Starting server...')
})

With the above structure, if the URL from the browser client is /index.html, test.css or test.jpeg, it will deliver one of these files, otherwise the client is presented with a 404, no such file error page.

Since errors are caught, we could provide some other routing mechanism in the catch method's callback. If the css and jpeg files were to be in the html document, they would be automatically requested from the server.

License

This module, and the code therein, is licensed under MIT.