import SchQ from 'schq/src/src/index.js'

public class | source

SchQ

SchQ is an event-scheduling pipeline that I’ve created to schedule d3 animations. It can also be used for preforming the same operation in any other sequence where controlling the order of events needs to be automatically canceled when the state of the application has changed.

Example:

// initialize SchQ
let config = {
   // schQ intentionally discards data when application state changes 
   // set lost data to the number of history items if you wish to track
   // that discarded data.
   lostData : 0,
   // a function to make a consistent array
   preprocess: (array) => {...do something},
   // what will happen last after sequence is done
   doLast: [[()=>console.log('done')]],
   // count items out for process
   checkout: (eachObject) => eachObject.opperation.length
};

let schQ = new SchQ(config);

// load data and a key
schQ.loader([[func,func],[func]], 'data');

// run
let subscriber = schQ.run();

// subcribe
subscriber
  .subscribe(packet => {
    let {message, next, emitter} = packet;
    // key is 'data'
    // previous is any data returned from events if not the first event
    let {key, previous} = message;
    next.forEach(operationThen => {
      operationThen( previous, emitter.emit({key}) );
    });
  });

Constructor Summary

Public Constructor
public	constructor(config: Object)

Method Summary

Public Methods
public	emitter(): Emitter SchQ.emitter: give access to the emitter to hook an event from another API
public	loader(next: Array, key: String) SchQ.loader: pushes data to the pipeline and gives the event listener a key to listen on.
public	run(): Observable SchQ.run: creates the Observable scheduler sequence

Public Constructors

public constructor(config: Object) source

Params:

Name	Type	Attribute	Description
config	Object	optional default: baseSetting	Object of arguments
config.checkout	Function	optional default: checkout	how schQ know how many operations are outstanding before pushing the next event
config.doLast	Function	optional default: doLast	what is performed when all process are finished. i.e. default is () => {}
config.lostData	Number	optional default: 0	Set the number of lost data items to track for tests or have another use cases
config.preprocess	Function	optional default: preprocess	create a interable i.e. default is an Array of Arrays of Functions

Public Methods

public emitter(): Emitter source

SchQ.emitter: give access to the emitter to hook an event from another API

Return:

Emitter

public loader(next: Array, key: String) source

SchQ.loader: pushes data to the pipeline and gives the event listener a key to listen on.

Params:

Name	Type	Attribute	Description
next	Array		an Array of Arrays that pushes each nested array to the subscribe of the like a queue.
key	String		This key is used to subscribe to an event before pushed down the pipeline. Once you subscribe to the pipeline this key will available via {}.message to emit on.

public run(): Observable source

SchQ.run: creates the Observable scheduler sequence

Return:

Observable

Observable on which to subscribe

Return Properties:

Name	Type	Attribute	Description
message	Object		object of event key and previous events
message.key	Object		key emitter is listening if on
message.previous	Array \| undefined		an array of previous events if not the first event, else undefined
next	Object		the operation to perform
emitter	Emitter		for emit