Simple command queue, so callbacks enqueued are called one after another.

queue = require "@tech_userreport.com/queue"

cmdq = queue()

cmdq.enqueue (next) ->
	setTimeout () ->
		console.log "I'll be called first"
		next()
	, 0

cmdq.enqueue (next) ->
	console.log "I'll be called second"
	next()

.enqueue(command)

Enqueue command to be called. Receiving callback which should be called once command is finished.

cmdq.enqueue (next) ->
	longRunningAsyncMethod () ->
		next()

.length

Count of commands in queue including one being executed

cmdq.enqueue (next) ->
	console.log cmdq.length # 1
	next()

.onchange

Subscribe to changes in queue. It's called when new command is added to queue or command had finished execution.

cmdq.onchange () ->
	# called two times
	# first call .length is 1
	# second call .length is 0
	console.log cmdq.length

cmdq.enqueue (next) ->
	next()

.pause

Pause queue processing.

queue = require "@tech_userreport.com/queue"

cmdq1 = queue()
cmdq2 = queue()

cmdq1.onchange () ->
	if cmdq1.length isnt 0
		cmdq2.pause()
	else
		cmdq2.resume()

.resume

Resume queue processing