queued-up

I wanted to build a task system that made sense, and was as simple and as powerful as it could be.
This queue module can run basic functions over a list of items, or run a series of async calls meant for vastly different things.

You can either save the resultant data, or simply perform each operation without it.

Pardon my dust. Functionality finished. Working on documenting all features.

Install

npm install queued-up

Usage

Input

The queued-up object returns a new instance of a queue. The primary input is the action function. This function, defined by you, will operate on each item in the queue. When the function is considered complete. Simply call this.done() within the function. Data may also be sent back to the queue for later retrieval by passing it into the done() function. See examples below.

Methods

Methods for the queue instance:

• .queue() - Returns the queue array
• .queue(\[,...\]) - Sets queue array to the input replacing existing items
• .add(input) - Adds the input to the end of the queue array
• .remove(number)- removes the queue item at the given index
• .index - returns the current iteration point of the queue
• .index(number) - sets the index manually
• .next() - processes the next item in the queue, and returns result.
• .next(n) - Processes the next n items in the queue. Get results from .results()
• .run() - begins processing queue while maintaining the queue
• .run(index) - begins processing queue at given index
• .shift() - Processes the first item in the queue, removes it, and returns the results
• .shift(n) - Performs .shift() for the next n items. Get results from .results()
• .shiftRun() - begins processing all items in the queue, removing each, and appending .results();
• .pause() - pauses the run() at current index or shiftRun().
• .resume() - resumes the queue run. Do not call this within the 'paused' eventhandler!
• .reset() - sets index(), queue(), and results() to zero and empty
• .results() - Returns the results array. Index matching run/next, or order of shift/shiftRun
• .shiftResults()- Returns the first item in the results array and removes it.

Methods for the action function:

• 'this.done()' - notifies the queue that the task is complete.
• 'this.done(data)'- notifies queue that task is complete, and sends data to .results()
• 'this.index()' - returns the index of the current queue item

Events

• 'complete' - Entire queue run has completed. Returns array of results
• 'paused' - Queue run has been paused
• 'resumed' - Queue run has been resumed
• 'taskdone' - A task has been completed. Returns {index: 0, data: thedata}. Not required to pull data from here.

Scenario - next(): Iterate over items with function

var qup = require('queued-up');
 
/*  Define the function called for each iteration.
*   End all action functions with this.done() to notify completion.
*   Passing this.done() with an argument will add the data to the results array queue.results().
*   Running this.done() as the return function will also return the data in .next() and .shift().
*/
function square(item){
    return this.done(item*item);
}
 
//Pass the action into the module, and a new queue object will be created.
var queue = new qup(square);
 
//add the items to the queue
queue.add([1,2,3,4,5,6]);
 
console.log(queue.next()); //returns 1
console.log(queue.next()); //returns 6
console.log(queue.next()); //returns 9
 
 
//.results() returns the array of results where the index
//matches the queued item.
console.log(queue.results());//returns [ 1, 4, 9 ]
//.queue returns the contents of the queued items.
console.log(queue.queue());//returns   [ 1, 2, 3, 4, 5, 6 ]

Scenario - shift(): Deplete the queue of items while applying the function.

var qup = require('queued-up');
 
/*  Define the function called for each iteration.
*   End all action functions with this.done() to notify completion.
*   Passing this.done() with an argument will add the data to the results array queue.results().
*   Running this.done() as the return function will also return the data in .next() and .shift().
*/
function square(item){
    return this.done(item*item);
}
 
//Pass the action into the module, and a new queue object will be created.
var queue = new qup(square);
 
//add the items to the queue
queue.add([1,2,3,4,5,6]);
 
console.log(queue.shift()); //returns 1
console.log(queue.shift()); //returns 6
console.log(queue.shift()); //returns 9
 
//.results() after a shift() returns the items in the order they were operated on.
console.log(queue.results());//returns [ 1, 4, 9 ]
//.queue after shift shows the remaining items.
console.log(queue.queue());//returns   [ 4, 5, 6 ]

Scenario - run(): complete the queued items while maintaining the queue.

var qup = require('queued-up');
 
function square(item){
    return this.done(item*item);
}
 
var queue = new qup(square);
 
//add the items to the queue
queue.add([1,2,3,4,5,6]);
 
//Run will run the action function for all items.
queue.run();
 
console.log(queue.results());//returns [ 1, 4, 9, 16, 25, 36 ]
 
console.log(queue.queue());//returns   [ 1, 2, 3, 4, 5, 6 ]

Scenario - shiftRun(): complete the queued items and deplete the queue.

var qup = require('queued-up');
 
function square(item){
    return this.done(item*item);
}
 
var queue = new qup(square);
 
//add the items to the queue
queue.add([1,2,3,4,5,6]);
 
//Run will run the action function for all items.
queue.shiftRun();
 
console.log(queue.results()); //returns [ 1, 4, 9, 16, 25, 36 ]
 
console.log(queue.queue()); //returns   []

Scenario - next(3) & shift(3): Process a set number of items in the queue.

Note that this would only return the last item. See .results() for the results of the processing. This can be useful if you wish to process items in chunks.

//will process the next 3 items in the queue.
queue.next(3);
//will process and remove the next 3 items.
queue.shift(3);

async examples and usage of the event system will be up soon. Please create an issue if you run into any problems, or would like to see something done differently.