express-progressbar

Node Progress Bar

A simple NodeJs module for sending progress from the server to the client.

Documentation

express-progressbar has two modes: - Handler mode: Handles everything: the request and the progress. - Request mode: Allows for more flexibility.

Handler mode

Requires Express

First you need to import the Handler object from express-progressbar. This handles setting up the server side page and clientside API.

The imported Handler object is a function, so you need to call it. It requires the following arguments:

• progressFunction: This function handles sending and stopping the progress. Its argument is a class:
  • update: The function sends a message to the client.
  • end: Closes the connection. You can also send more data into these functions as a second argument.
• fileLocation: The path of the file that handles the client side progress event. Handler automatically creates a server get handler for this file.
• url: The URL that the user has to type into the address bar. This is the same as you would put into app.get
• app: The Express function
• progressLocation: The location that you have to go to to receive the progress values. Defaults to progress.

You can also pass fs, and path (in that order) after the required arguments.

The request and response attributes are also available as the second and third arguments in the progressFunction.

The client file can now require express-progressbar like this:

const { Handler } = require('express-progressbar');
 
Handler(p => {
    let i = 0;
 
    const int = setInterval(() => {
        if (i > 10) {
            p.close();
            clearInterval(int);
        } else {
            p.update(i / 10 * 100, {
                isCool: true
            });
            i++;
        }
    }, 1000);
}, __dirname + '/index.html', '*', app, 'WebURL' /*, fs, path*/);

The passed object is a function that gets called when the server sends a progress event. This function also returns the EventSource.

Take a look at the example files folder for a better explanation.

Request mode

First you need to import the Progress object from express-progressbar. This is only the Progress class. You need to setup the code on the client-side your self (you can take a look at the example on how to do that).

The Progress constructor's only argument is the response object. The Progress class has the following functions:

• update Synonym for sendProgress
• end/close: Synonym for closeConnection
• sendProgress: ([Number] percentage, [Object] moreData)
• closeConnection: ([Object] moreData)
• constructSSE: ([Express response object] response, [String] id, [String] data) - This function is not necessary to use.

The client file can now require express-progressbar like this:

const { Progress } = require('express-progressbar');
 
app.get('/progress', (request, response) => {
    const p = new Progress(response);
 
    let i = 0;
    const int = setInterval(() => {
        if (i > 10) {
            p.close();
            clearInterval(int);
        } else {
            p.update(i / 10 * 100, {
                isCool: true
            });
 
            i++;
        }
    }, 1000);
});

Take a look at the example files folder for a better explanation.