finalhandler

Node.js final http responder

finalhandler

Node.js function to invoke as the final step to respond to HTTP request.

Installation

$ npm install finalhandler

API

var finalhandler = require('finalhandler')

finalhandler(req, res, [options])

Returns function to be invoked as the final step for the given req and res. This function is to be invoked as fn(err). If err is falsy, the handler will write out a 404 response to the res. If it is truthy, an error response will be written out to the res, and res.statusCode is set from err.status.

The final handler will also unpipe anything from req when it is invoked.

options.env

By default, the environment is determined by NODE_ENV variable, but it can be overridden by this option.

options.onerror

Provide a function to be called with the err when it exists. Can be used for writing errors to a central location without excessive function generation. Called as onerror(err, req, res).

Examples

always 404

var finalhandler = require('finalhandler')
var http = require('http')
 
var server = http.createServer(function (req, res) {
  var done = finalhandler(req, res)
  done()
})
 
server.listen(3000)

perform simple action

var finalhandler = require('finalhandler')
var fs = require('fs')
var http = require('http')
 
var server = http.createServer(function (req, res) {
  var done = finalhandler(req, res)
 
  fs.readFile('index.html', function (err, buf) {
    if (err) return done(err)
    res.setHeader('Content-Type', 'text/html')
    res.end(buf)
  })
})
 
server.listen(3000)

use with middleware-style functions

var finalhandler = require('finalhandler')
var http = require('http')
var serveStatic = require('serve-static')
 
var serve = serveStatic('public')
 
var server = http.createServer(function (req, res) {
  var done = finalhandler(req, res)
  serve(req, res, done)
})
 
server.listen(3000)

keep log of all errors

var finalhandler = require('finalhandler')
var fs = require('fs')
var http = require('http')
 
var server = http.createServer(function (req, res) {
  var done = finalhandler(req, res, {onerror: logerror})
 
  fs.readFile('index.html', function (err, buf) {
    if (err) return done(err)
    res.setHeader('Content-Type', 'text/html')
    res.end(buf)
  })
})
 
server.listen(3000)
 
function logerror(err) {
  console.error(err.stack || err.toString())
}

License

MIT