Progress bars within vorpal

[chrisui]

Hey! Firstly, to the maintainers and contributors, awesome library. This is my first time venturing into making any sort of cli tooling and vorpal has made it an absolute dream to work on - so much fun!

Secondly I was wondering if anyone have any recommendations for handling progress bars within my vorpal commands? I am using progress and it seems to work fine however I am a little concious of the fact it is not logging via vorpal.log after reading the logging documentation.

Am I going to run into issues down the line? Is there already an awesome vorpal progress plugin? If not and I am going to run into issues down the line perhaps there is a way we could implement this as a plugin/extension easily?

[tobilg]

I also use progress for progress bars together with vorpal. So far, I didn't encounter any problem, but also would appreciate a way to integrate this better...

[tobilg]

I had a look at the sources, and you can pass the progress module a stream property, which it will then use as output stream.

Unfortunately I didn't find way to access the console.log stream of vorpal because IMO it's not exposed.

[LongLiveCHIEF]

I had this use case a few months ago, and wrote a binary downloader that output progress to the vorpal console, using the stream method @tobilg mentioned, although I did it without using the progress module, and simply returned writeStream.byesWritten on each tick. Here's what I did (I used rxjs to add some helper methods, but this can be done w/out that dependency):

The main trick here is to use the vorpal.ui.redraw command:

// file:  /lib/commands/update.js
var fs = require('fs');
var path = require('path');
require('rxjs/add/operator/filter');
var updateBinaries = require('../update-binaries');

module.exports = function(vorpal){
  vorpal
    .command('update')
    .description('update core binaries')
    .action(function(args, callback){
      updateBinaries(needsInstalled)
        .subscribe(
          function(update){
            vorpal.ui.redraw(update);
          },
          function(){
            vorpal.ui.redraw.done();
            vorpal.log('there was an error while downloading file')
          },
          function(){
            vorpal.ui.redraw.done();
            vorpal.log("download completed");
          }
        );
      callback();
    });
}

// file: ../update-binaries.js

var request = require('request');
var fs = require('fs');
var path = require('path');
var {Observable} = require('rxjs/Observable');

var Download = function binaryDownloadObservable(url, downloadPath){

  return Observable.create(function(observer){
    var stream = request;
    var fileWriter = fs.createWriteStream(downloadPath);

    stream
      .get(url)
      .on('response', function(response){
        observer.next({
          "event": "response",
          "data": response.headers['content-length']
        });
      })
      .on('data', function(data){
        observer.next({
          "event": "chunk",
          "data": fileWriter.bytesWritten
        })
      })
      .on('error', function(error){
        observer.error(error);
      })
      .on('end', function(){
        observer.complete();
      })
      .pipe(fileWriter);

      return function(){
        fileWriter.end();
      }
  });
}