queueback

Callback queue system for optimizing HTTP requests by reducing potential
duplicate requests. It basically allows you to queue callbacks based on HTTP
method and URL.

Install

The module is released as ES6 module in the npm registry and can be installed
using:

``
npm install --save queueback
`

API

Import and construct the queue using the following syntax:

`js
import Queue from 'queueback';

const queue = new Queue();
`

$3

Add a new callback to a method and URL specific queue. The method accepts the
following arguments:

- method HTTP method
- url URL that is being requested
- fn Callback to queue

The method will return a boolean that is an indication if we have queue in
process for this callback so no new request should be made.

`js
if (queue.add('GET', 'http://google.com', fn)) return;
`

Please note that we guarantee that the callback is only called once and removed
from the queue after execution.

$3

Remove an added callback from the queue. The method accepts the following
arguments:

- method HTTP method
- url URL that is being requested
- fn Callback to remove

`js
function fn() {
throw new Error('I should never be called');
}

queue.add('GET', 'https://google.com', fn);
queue.remove('GET', 'https://google.com', fn);
queue.run('GET', 'https://google.com');
`

$3

This allows you to execute all queued callbacks for the given method and URL
combination. It accepts the following arguments.

- method HTTP method
- url URL that is being requested

All of the other arguments are passed in to the queued callbacks.

`js
queue.run('GET', 'http://google.com', new Error('Failed to load google'));
`

$3

Execute all the queued callbacks regardless of their method and URL
combinations. All arguments are passed in to the queued callbacks.

`js
queue.all(new Error('Unable to authenticate with server'));
``

License

MIT