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

const { DownloaderHelper } = require('node-downloader-helper');
const dl = new DownloaderHelper('http://www.ovh.net/files/1Gio.dat', __dirname);

dl.on('end', () => console.log('Download Completed'))
dl.start();

CLI

This can be used as standalone CLI downloader

Install npm i -g node-downloader-helper

Usage: ndh [folder] [url]

$ 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

{
    method: 'GET', // Request Method Verb
    headers: {},  // Custom HTTP Header ex: Authorization, User-Agent
    fileName: string|cb(fileName, filePath)|{name, ext}, // Custom filename when saved
    retry: false, // { maxRetries: number, delay: number in ms } or false to disable (default)
    forceResume: false, // If the server does not return the "accept-ranges" header, can be force if it does support it
    removeOnStop: true, // remove the file when is stopped (default:true)
    removeOnFail: true, // remove the file when fail (default:true)
    override: boolean|{skip, skipSmaller}, // Behavior when local file already exists
    httpRequestOptions: {}, // Override the http request options  
    httpsRequestOptions: {}, // Override the https request options, ex: to add SSL Certs
}

for fileName you can provide 3 types of parameter

• string: will use the full string as the filename including extension
• callback(fileName, filePath): must return an string, only sync function are supported ex: (fileName) => 'PREFIX_' + fileName;
• 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

{
    totalSize:, // total file size got from the server
    fileName:, // original file name
    filePath:, // original path name
    downloadedSize:, // the downloaded amount
}

event download downloadInfo object

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

event progress or progress.throttled stats object

{
    name:, // file name
    total:, // total size that needs to be downloaded in bytes
    downloaded:, // downloaded size in bytes
    progress:, // progress porcentage 0-100%
    speed: // download speed in bytes
}

event end downloadInfo object

{
    fileName:, 
    filePath:,
    totalSize:, // total file size got from the server
    incomplete:, // true/false if the download endend but still incomplete
    onDiskSize, // total size of file on the disk
    downloadedSize:, // the total size downloaded
}

event renamed filePaths object

{
    path:, // modified path name
    fileName:, // modified file name
    prevPath:, // original path name
    prevFileName:, // original file name
}

event error error object

{
    message:, // Error message
    status:, // Http status response if available
    body:, // Http body response if available
}

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