non-caching require() for live coding
npm install uncache
uncache
=======
Like require(), but do not put the required package into the cache to facilitate live coding
(actually, it removes the required module from the cache!).
What Can You Do?
----------------
* Create a web server that you don't have to restart when you change the code.
Usage
-----
``javascript`
var live = require('uncache')(require)
Now, use live('module') instead of require('module').
It will load the file each time.
`javascript`
var func = live.function('./module')
When func() is called, it will reload the module before calling it.
Of course, this assumes that the module exports a function.
Use Cases
---------
One annoying thing when creating web applications with Node.js
is that you have to restart the server when you change the code.
Even with nodemon that restarts the server automatically,
it's still annoying.
Since the app returned by express() is a function
that can be passed to http.createServer,
you can create a web server like this:
`javascript
var live = require('uncache')(require)
var http = require('http')
http.createServer(live.function('./app'))
.listen(3002, '127.0.0.1')
`
And app.js like this:
`javascript
var express = require('express')
var app = module.exports = express()
app.get('/', function(req, res, next) {
res.send('hello')
})
`
Each time you send a request to this server,
a new application is created.
That means when you change the code,
for example, from 'hello' to 'world',
and then refresh the page.
__Going live:__ when you want to go production,
just change live.function to require, and it's done!
What It Does Not Do
-------------------
This module is only concerned about making require() clear the cache.
It does not have these features:
Create your own abstraction, such as:
`javascript`
function load(module) {
return (process.env.NODE_ENV == 'production') ? require(module) : live(module)
}
Maybe you can use a global variable for this.
Here is a cleanup function:
`javascript
function cleanup(module, fn) {
var key = 'cleanup:' + module.id
// If there is a cleanup function for this module,
// this means the module is loaded, so, call it:
if (global[key]) {
global[key]()
}
// Register the cleanup function.
global[key] = fn
}
`
When cleanup is called the second time (when the module is reloaded),
it will detect the cleanup function from the first load and run it.
`javascript
console.log('Start up!')
cleanup(module, function() {
console.log('Shut down!')
})
``