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    finalhandler
    DefinitelyTyped icon, indicating that this package has TypeScript declarations provided by the separate @types/finalhandler package

    1.1.2 • Public • Published

    finalhandler

    NPM Version NPM Downloads Node.js Version Build Status Test Coverage

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

    Installation

    This is a Node.js module available through the npm registry. Installation is done using the npm install command:

    $ 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.

    When an error is written, the following information is added to the response:

    • The res.statusCode is set from err.status (or err.statusCode). If this value is outside the 4xx or 5xx range, it will be set to 500.
    • The res.statusMessage is set according to the status code.
    • The body will be the HTML of the status code message if env is 'production', otherwise will be err.stack.
    • Any headers specified in an err.headers object.

    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

    Keywords

    none

    Install

    npm i finalhandler

    DownloadsWeekly Downloads

    18,479,112

    Version

    1.1.2

    License

    MIT

    Unpacked Size

    17 kB

    Total Files

    5

    Last publish

    Collaborators

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