express-history-api-fallback

A tiny, accurate, fast Express middleware for single page apps with client side routing.



Works as a middleware for Express. Can be used as either an application middleware or a router middleware.

``js
import fallback from 'express-history-api-fallback'
import express from 'express'
const app = express()
const root = ${__dirname}/public
app.use(express.static(root))
app.use(fallback('index.html', { root }))
`
Or in ECMAScript 5:
`js
var fallback = require('express-history-api-fallback')
var express = require('express')
var app = express()
var root = __dirname + '/public'
app.use(express.static(root))
app.use(fallback('index.html', { root: root }))
`

fallback(path[, options])

Returns a middleware for use by Express applications and routers.

Arguments are passed to res.sendFile() in express@>=v4.8.0, or res.sendfile() otherwise.

Absolute path:
`js
app.use(fallback(__dirname + '/dist/app.html'))
`
Relative path:
`js
app.use(fallback('dist/app.html', { root: __dirname }))
`

$3

Location of the HTML file containing single page app entry point.

Unless the root option is set in the options object, path must be an absolute path of the file.

$3


Valid options are maxAge, root, lastModified, headers, and dotfiles. See Response.sendFile() for details. Note that only maxAge and root are supported with express@<4.8.

But doesn't this already exist?

Yes, but this implementation is much better.

- Only for GET (and HEAD) requests: The fallback should not serve your index.html for POST or other requests.
- Only for HTML requests: Never serve mistakenly for JS or CSS or image or other static file requests. Less debugging headaches.
- Only when needed: Serve the fallback only when the file is missing.
- High performance: Let res.sendFile() in Express >=4.8.0` do the heavy lifting of serving the file.
- Minimal code: Just a few lines. No magic. No complexity.

See the blog post "Single Page App Routing with Express & Node.js" for an overview of the problems with alternative middlewares.