node-downloader-helper

A simple http file downloader for node.js

Features:

• No thirdparty dependecies
• Pause/Resume
• Retry on fail
• Supports http/https
• Supports http redirects
• Supports pipes
• Custom native http request options
• Usable on vanilla nodejs, electron, nwjs
• Progress stats

Install

$ npm install --save node-downloader-helper

Usage

For a more complete example check example folder

1const { DownloaderHelper } = require('node-downloader-helper');
2const dl = new DownloaderHelper('http://www.ovh.net/files/1Gio.dat', __dirname);
3
4dl.on('end', () => console.log('Download Completed'))
5dl.start();

CLI

This can be used as standalone CLI downloader

Install npm i -g node-downloader-helper

Usage: ndh [folder] [url]

1$ ndh ./folder http://url

Options

Download Helper constructor also allow a 3rd parameter to set some options constructor(url, destinationFolder, options), these are the default values

1{
2    method: 'GET', // Request Method Verb
3    headers: {},  // Custom HTTP Header ex: Authorization, User-Agent
4    fileName: string|cb(fileName, filePath, contentType)|{name, ext}, // Custom filename when saved
5    retry: false, // { maxRetries: number, delay: number in ms } or false to disable (default)
6    forceResume: false, // If the server does not return the "accept-ranges" header, can be force if it does support it
7    removeOnStop: true, // remove the file when is stopped (default:true)
8    removeOnFail: true, // remove the file when fail (default:true)
9    progressThrottle: 1000, // interval time of the 'progress.throttled' event will be emitted
10    override: boolean|{skip, skipSmaller}, // Behavior when local file already exists
11    httpRequestOptions: {}, // Override the http request options  
12    httpsRequestOptions: {}, // Override the https request options, ex: to add SSL Certs
13}

for fileName you can provide 3 types of parameter

• string: will use the full string as the filename including extension
• callback(fileName, filePath, contentType): must return an string, only sync function are supported ex: (fileName) => 'PREFIX_' + fileName;, contentType will be provided if available
• object: this object must contain a name attribute and an optional ext attribute, the ext attribute can be an string without dot(.) or a boolean where true use the name as full file name (same as just giving an string to the fileName parameter) or false (default) will only replace the name and keep the original extension, for example if the original name is myfile.zip and the option is {name: 'somename'} the output will be somename.zip

for override you can provide 2 types of parameter

• boolean: true to override existing local file, false to append '(number)' to new file name
• object: object with properties skip (boolean): whether to skip download if file exists, and skipSmaller (boolean): whether to skip download if file exists but is smaller. Both default to false, for the equivalent of override: true.

for httpRequestOptions the available options are detailed in here https://nodejs.org/api/http.html#http_http_request_options_callback

for httpsRequestOptions the available options are detailed in here https://nodejs.org/api/https.html#https_https_request_options_callback

Methods

Name	Description
start	starts the downloading
pause	pause the downloading
resume	resume the downloading if supported, if not it will start from the beginning
stop	stop the downloading and remove the file
pipe	readable.pipe(stream.Readable, options) : stream.Readable
unpipe	(stream) if not stream is not specified, then all pipes are detached.
updateOptions	(options) updates the options, can be use on pause/resume events
getStats	returns stats from the current download, these are the same stats sent via progress event
getTotalSize	gets the total file size from the server
getDownloadPath	gets the full path where the file will be downloaded (available after the start phase)
isResumable	return true/false if the download can be resumable (available after the start phase)

Events

Name	Description
start	Emitted when the .start method is called
skip	Emitted when the download is skipped because the file already exists
download	Emitted when the download starts callback(downloadInfo)
progress	Emitted every time gets data from the server callback(stats)
progress.throttled	The same as progress but emits every 1 second while is downloading callback(stats)
retry	Emitted when the download fails and retry is enabled callback(attempt, retryOpts)
end	Emitted when the downloading has finished callback(downloadInfo)
error	Emitted when there is any error callback(error)
timeout	Emitted when the underlying socket times out from inactivity.
pause	Emitted when the .pause method is called
resume	Emitted when the .resume method is called callback(isResume)
stop	Emitted when the .stop method is called
renamed	Emitted when '(number)' is appended to the end of file, this requires override:false opt, callback(filePaths)
stateChanged	Emitted when the state changes callback(state)

event skip skipInfo object

1{
2    totalSize:, // total file size got from the server
3    fileName:, // original file name
4    filePath:, // original path name
5    downloadedSize:, // the downloaded amount
6}

event download downloadInfo object

1{
2    totalSize:, // total file size got from the server
3    fileName:, // assigned name
4    filePath:, // download path
5    isResumed:, // if the download is a resume,
6    downloadedSize:, // the downloaded amount (only if is resumed otherwise always 0)
7}

event progress or progress.throttled stats object

1{
2    name:, // file name
3    total:, // total size that needs to be downloaded in bytes
4    downloaded:, // downloaded size in bytes
5    progress:, // progress porcentage 0-100%
6    speed: // download speed in bytes
7}

event end downloadInfo object

1{
2    fileName:, 
3    filePath:,
4    totalSize:, // total file size got from the server
5    incomplete:, // true/false if the download endend but still incomplete
6    onDiskSize, // total size of file on the disk
7    downloadedSize:, // the total size downloaded
8}

event renamed filePaths object

1{
2    path:, // modified path name
3    fileName:, // modified file name
4    prevPath:, // original path name
5    prevFileName:, // original file name
6}

event error error object

1{
2    message:, // Error message
3    status:, // Http status response if available
4    body:, // Http body response if available
5}

States

Name	Value
IDLE	'IDLE'
SKIPPED	'SKIPPED'
STARTED	'STARTED'
DOWNLOADING	'DOWNLOADING'
PAUSED	'PAUSED'
RESUMED	'RESUMED'
STOPPED	'STOPPED'
FINISHED	'FINISHED'
FAILED	'FAILED'
RETRY	'RETRY'

Test

$ npm test

License

Read License for more licensing information.

Contributing

Read here for more information.

TODO

• Better code testing