Progression

Progression reports a 0.0 - 1.0 progress of a tree of tasks where each task can have an arbitrarily assigned weight (default weight is 1.0 per task).

Within the tree of tasks, tasks can either be in progress or completed.

Tasks can be a simple object with an id and weight or another Progression object, allowing you to build complex trees of asynchronous tasks and keep track of how "done" the entire process is.

Examples

Simple Use Case

var Progression = require('progression');
var progress = new Progression();

// Add task with a weight of 1.0
progress.addTask('main');

// Add a subtask of 'main' with a weight of 0.1 and an id of 'sub'
progress.addTask({id: 'sub', weight: 0.1}, 'main');

// Note: total weight now is 1.1 for all tasks.


const onProgress = function () {
  console.log('Progress: ' + (progress.getProgress() * 100) + '%');
};
const onCompleted = function (task) {
  console.log('The task: ' + task.id + ' has been completed');
};
const onFinished = function () {
  console.log('All tasks have been completed!');
};

// Add event listeners to watch what is happening.
progress.on('progress', onProgress);
progress.on('completed', onCompleted);
progress.on('finished', onFinished);

progress.progress('sub'); // This will trigger a 'progress' event and a 'completed' event for the subtask.
progress.progress('main'); // Complete the final task and dispatch all three events: 'progress', 'completed', and 'finished'

// Cleanup
progress.removeListener('progress', onProgress);
progress.removeListener('completed', onCompleted);
progress.removeListener('finished', onFinished);

Options

var progress = new Progression(options);

• options.completedWhenEmpty: when true, if the progression has no tasks getProgress() will return 1.0. Default is false.

Resetting

If you want to clear out all tasks and start over:

progress.reset();

Task Trees

Because each Progression instance can add other Progression instances as children, you can create trees of tasks/progression instances. The base Progression will accurately report the overall progress of all its descendents.

var Progression = require('progression');

var parentProgression = new Progression('parent');
var childProgression = new Progression('someChildName');
childProgression.addTask('task1');

parentProgression.addTask(childProgress);

...

childProgress.progress('task1');

console.log(parentProgression.getProgress() == 1.0); // true

Extending

Progression uses jclass, which is an implementation of John Resig's simple inheritance model.

You can easily extend Progression:

var MyCustomProgression = Progression._extend({
  ...
  init: function (id) 
  {
    console.log('My custom progression!');
    this._super(id);
  }
  ...
});

var myCustomProgression = new MyCustomProgression();

See the jclass documentation for more information.

License

The MIT License (MIT)

Copyright (c) 2014 Joshua Jung

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.