nodejs-file-downloader

nodejs-file-downloader is a simple utility for downloading files. It hides the complexity of dealing with streams, paths and duplicate file names. Can automatically repeat failed requests.

If you encounter any bugs or have a question, please don't hesitate to open an issue.

Installation

$ npm install nodejs-file-downloader

Table of Contents

• Examples
  • Basic
  • Get the progress of a download
  • Custom file name
  • Overwrite existing files
  • Get response and then download
  • Repeat failed requests automatically

Examples

Basic

Download a large file with default configuration

const Downloader = require('nodejs-file-downloader');

(async () => {//Wrapping the code with an async function, just for the sake of example.

    const downloader = new Downloader({     
      url: 'http://212.183.159.230/200MB.zip',//If the file name already exists, a new file with the name 200MB1.zip is created.     
      directory: "./downloads",//This folder will be created, if it doesn't exist.               
    })
    
    await downloader.download();//Downloader.download() returns a promise.

    console.log('All done');

})();    

 

Get the progress of a download

const Downloader = require('nodejs-file-downloader');

(async () => {

   const downloader = new Downloader({     
      url: 'http://212.183.159.230/200MB.zip',     
      directory: "./downloads/2020/May",//Sub directories will also be automatically created if they do not exist.  
      onProgress:function(percentage){//Gets called with each chunk.
           console.log('% ',percentage)   
      }         
    })    
    
    await downloader.download();   

})();    

 

Custom file name

Normally, nodejs-file-downloader "deduces" the file name, from the URL or the response headers. If you want to choose a custom file name, supply a config.fileName property.

  const downloader = new Downloader({     
      url: 'http://212.183.159.230/200MB.zip',     
      directory: "./downloads/2020/May", 
      fileName:'somename.zip'//This will be the file name.        
  }) 

 

Overwrite existing files

By default, nodejs-file-downloader uses config.cloneFiles = true, which means that files with an existing name, will have a number appended to them.

  const downloader = new Downloader({     
      url: 'http://212.183.159.230/200MB.zip',     
      directory: "./",  
      cloneFiles:false//This will cause the downloader to re-write an existing file.   
  }) 

 

Get response and then download

There is an alternative way to using Downloader.download():

  const downloader = new Downloader({     
      url: 'http://212.183.159.230/200MB.zip',     
      directory: "./",        
  }) 

  const response = await downloader.request()//This function just performs the request. The file isn't actually being downloaded yet. It returns an Axios response object. You can refer to their docs for more details.

  //Now you can do something with the response, like check the headers
  if(response.headers['content-length'] < 1000000){
    await downloader.save()
  }else{
    console.log('File is too big!')
  }  

  //Note that Downloader.download() simply combines these two function calls.

 

Repeat failed requests automatically

The program can repeat any failed http request automatically. Only if the provided config.maxAttempts number is exceeded, an Error is thrown.

Note that currently only the http requests will be repeated in case of an error, BUT NOT THE STREAM ITSELF. If a stream fails on its first attempt, an error is thrown as usual. I will change this behavior in the future.

  const downloader = new Downloader({     
      url: 'http://212.183.159.230/200MB.zip',     
      directory: "./",
      maxAttempts:3,//Default is 1.
      onError:function(error){//You can also hook into each failed http request attempt.
        console.log('Error from attempt ',error)
      }        
  })   

  await downloader.dowload();