qfi

QFI - a function processing queue for node.js

qfi ( /ˈkjuːfi/; named cue-fi) is the love child of an array and an eventemitter

it supports all

• array https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array
• and eventemitter http://nodejs.org/docs/v0.4.7/api/events.html

methods and properties. this is allready useful in itself, but there is more.

additonal qfi supports various native methods to

• store
• execute
• delay
• iterate

functions.

USE CASES

• usefull if you work with REST APIs that have rate limits.
• zillion other things

INSTALL

  var q = require('/path/to/qfi.js');
  

or via npm (not yet published)

  >npm install qfi
  var q = require('qfi');
  

Q

the 'q' part of 'qfi'

q properties

//if true, q is in daemon modus (waits for new things to execute)
//default false
q.daemon

//time between executions, default 0
q.outtime

//a precondition callback //if false, the execution loop breaks q.breakIf() //if the loop breaks, this callback is called q.breakcallback(pointer)

//if the exectuion loop exits, this callback is called
q.exitcallback()

q methods

  //returns a new FunctionItem
  q.createFunctionItem(func, args, thisarg, eventname)
  
  //adds a new FunctionItem to q
  //more details see the section about FunctionItem
  q.add(func, args, thisarg, eventname)
  //===
  q.addFunctionItem(func, args, thisarg, eventname)

  //set the properties of q
  q.setConf(confobject)
  
  //start daemon mode
  //q waits if new FunctionItems get added (and then executes them)
  q.startDaemon()

  //turn of deamon mode
  q.stopDaemon()

  //executes all stored FunctionItems from q[0]
  //takes an optional conf object -> see q.setConf
  q.start(conf) 
  // ===
  q.restart(conf)

  //stop execution of FunctionItems  
  q.stop(conf) 
  
  //if execution of FunctionItems was stopped
  //`resume` continues execution where it was stopped
  q.resume(conf)
  
  //executes all FunctionItmes starting from q[start]
  q.startAt(start, conf)
  
  //stops execution before q[stop] gets executed
  q.breakBefore(stop,conf) 
  
  //stops execution after q[stop] was executed
  q.breakAfter(stop,conf)

  //deletes the brek set with q.breakBefore and q.breakAfter  
  q.clearBreak(stop,conf)
  
  //start execution from q[start], stop execution before q[stop] 
  q.startAtbreakBefore(start, stop, conf)

  //pauses execution for `milsec` milseconds 
  //q.pause(milsec,conf)

  //define how fast the FunctionItmes in q get executed (how many `hits`(executions) during `milisec`) 
  //q.setRate(hits, milsec)

  //how many executions should happen in one second
  q.setSecondRate(hits)

  //how many executions should happen in one minute/hour/day 
  q.setMinuteRate()
  q.setHourlyRate() 
  q.setDailyRate()

  //add an event listener to q
  //inherited from eventemitter
  q.on(eventname, callback)
  
  //create a new (blank) q
  var q2 = q.create()

FUNCTIONITEM

the 'fi' part of 'qfi'

FunctionItem properties

  //stores a function 
  q[n].func
  
  //storeas an arguements array
  q[n].args

  //stores a `this` value of `func`
  q[n].thisarg

  //after `func` gets executed, this event is emitted (with the returnvalue of `func`)
  //note: very cool and powerful
  q[n].eventname
  //note: if no eventname is given, no event will be emitted

FunctionItem methods

  //FunctionItems are ...ta da... functions 
  //executes the stored FunctionItem, with the values storred in FuncionItem
  q[n]()
  //===
  q[n].execute()
  //===
  q[n].x()

  //similar to https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/function/apply
  // applies thisarg and args instead of the FunctionItems storred values
  q[n].apply(thisarg, args)

  //similar to https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/function/call
  //applies thisarg and arg1, ... instead of the FunctionItems storred values
  q[n].call(thisarg, arg1, arg2, arg3, ...)