grouped-queue
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In memory queue system prioritizing tasks
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Grouped Queue [](https://travis-ci.org/SBoudrias/grouped-queue)
==============
In memory queue system prioritizing tasks.
Documentation
=============
Installation
-------------
``` bash
$ npm install --save grouped-queue
```
Methods
------------
### Constructor
The constructor takes an optional array of task groups. The first `String` name will be the first queue to be emptied, the second string will be the second group emptied, etc.
By default, the constructor will always add a `default` queue in the last position. You can overwrite the position of the `default` group if you specify it explicitly.
``` javascript
var Queue = require('grouped-queue');
var queue = new Queue([ 'first', 'second', 'third' ]);
```
### Queue#add `add( [group], task, [options] )`
Add a task into a group queue. If no group name is specified, `default` will be used.
Implicitly, each time you add a task, the queue will start emptying (if not already running).
Each task function is passed a callback function. This callback must be called when the task is complete.
``` javascript
queue.add(function( cb ) {
DB.fetch().then( cb );
});
```
#### Option: `once`
You can register tasks in queues that will be dropped if they're already planned. This is done with the `once` option. You pass a String (basically a name) to the `once` option.
``` javascript
// This one will eventually run
queue.add( method, { once: "readDB" });
// This one will be dropped as `method` is currently in the queue
queue.add( method3, { once: "readDB" });
```
#### Option: `run`
You can register a task without launching the run loop by passing the argument `run: false`.
```javascript
queue.add( method, { run: false });
```
### Pro tip
Bind your tasks with context and arguments!
``` javascript
var task = function( models, cb ) {
/* you get `models` data here! */
};
queue.add( task.bind(null, models) );
```
### That's all?
Yes!
Events
-------------
### `end`
This event is called **each time** the queue emptied itself.
Contributing
=====================
**Style Guide**: Please base yourself on [Idiomatic.js](https://github.com/rwldrn/idiomatic.js) style guide with two space indent
**Unit test**: Unit tests are written in Mocha. Please add a unit test for every new feature
or bug fix. `npm test` to run the test suite.
**Documentation**: Add documentation for every API change. Feel free to send corrections
or better docs!
**Pull Requests**: Send _fixes_ PR on the `master` branch.
License
=====================
Copyright (c) 2013 Simon Boudrias (twitter: @vaxilart)
Licensed under the MIT license.