What is send?
The 'send' npm package is a library for streaming files from the file system as an HTTP response. It handles range requests, redirects, and errors, and is built with security in mind. It is often used to serve static files in web applications.
What are send's main functionalities?
Serving static files
This code creates an HTTP server that serves a static file using the send package. When a request is made to the server, it streams the specified file as the response.
const send = require('send');
const http = require('http');
http.createServer(function(req, res){
send(req, '/path/to/public/index.html').pipe(res);
}).listen(3000);
Handling range requests
This code demonstrates how to handle HTTP range requests for partial content delivery, such as serving video files that can be streamed.
const send = require('send');
const http = require('http');
http.createServer(function(req, res){
send(req, '/path/to/public/video.mp4')
.on('headers', function (res, path, stat) {
res.setHeader('Accept-Ranges', 'bytes');
})
.pipe(res);
}).listen(3000);
Custom error handling
This code shows how to handle errors when a file is not found or another error occurs while trying to stream a file.
const send = require('send');
const http = require('http');
http.createServer(function(req, res){
send(req, '/path/to/public/non-existent-file.html')
.on('error', function(err) {
res.statusCode = err.status || 500;
res.end(err.message);
})
.pipe(res);
}).listen(3000);
Other packages similar to send
express
Express is a web application framework for Node.js that includes functionality for serving static files. It is more feature-rich than 'send' and is designed for building web applications and APIs.
koa-send
koa-send is similar to 'send' but is tailored for Koa, a web framework for Node.js created by the same team that built Express. It is used to serve static files in Koa applications.
serve-static
serve-static is a middleware for serving static files for Express and Connect. It is built on top of 'send' and provides a higher-level API for integrating with these frameworks.
send
Send is Connect's static()
extracted for generalized use, a streaming static file
server supporting partial responses (Ranges), conditional-GET negotiation, high test coverage, and granular events which may be leveraged to take appropriate actions in your application or framework.
Installation
$ npm install send
Examples
Small:
var http = require('http');
var send = require('send');
var app = http.createServer(function(req, res){
send(req, req.url).pipe(res);
}).listen(3000);
Serving from a root directory with custom error-handling:
var http = require('http');
var send = require('send');
var url = require('url');
var app = http.createServer(function(req, res){
function error(err) {
res.statusCode = err.status || 500;
res.end(err.message);
}
function headers(res, path, stat) {
res.setHeader('Content-Disposition', 'attachment');
}
function redirect() {
res.statusCode = 301;
res.setHeader('Location', req.url + '/');
res.end('Redirecting to ' + req.url + '/');
}
send(req, url.parse(req.url).pathname, {root: '/www/example.com/public'})
.on('error', error)
.on('directory', redirect)
.on('headers', headers)
.pipe(res);
}).listen(3000);
API
Options
etag
Enable or disable etag generation, defaults to true.
dotfiles
Set how "dotfiles" are treated when encountered. A dotfile is a file
or directory that begins with a dot ("."). Note this check is done on
the path itself without checking if the path actually exists on the
disk. If root
is specified, only the dotfiles above the root are
checked (i.e. the root itself can be within a dotfile when when set
to "deny").
The default value is 'ignore'
.
'allow'
No special treatment for dotfiles.'deny'
Send a 403 for any request for a dotfile.'ignore'
Pretend like the dotfile does not exist and 404.
extensions
If a given file doesn't exist, try appending one of the given extensions,
in the given order. By default, this is disabled (set to false
). An
example value that will serve extension-less HTML files: ['html', 'htm']
.
This is skipped if the requested file already has an extension.
index
By default send supports "index.html" files, to disable this
set false
or to supply a new index pass a string or an array
in preferred order.
maxAge
Provide a max-age in milliseconds for http caching, defaults to 0.
This can also be a string accepted by the
ms module.
root
Serve files relative to path
.
Events
error
an error occurred (err)
directory
a directory was requestedfile
a file was requested (path, stat)
headers
the headers are about to be set on a file (res, path, stat)
stream
file streaming has started (stream)
end
streaming has completed
Error-handling
By default when no error
listeners are present an automatic response will be made, otherwise you have full control over the response, aka you may show a 5xx page etc.
Caching
It does not perform internal caching, you should use a reverse proxy cache such
as Varnish for this, or those fancy things called CDNs. If your application is small enough that it would benefit from single-node memory caching, it's small enough that it does not need caching at all ;).
Debugging
To enable debug()
instrumentation output export DEBUG:
$ DEBUG=send node app
Running tests
$ npm install
$ npm test
License
(The MIT License)
Copyright (c) 2012 TJ Holowaychuk <tj@vision-media.ca>
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.