hs.timer.md

docs » hs.timer

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Execute functions with various timing rules

Submodules

• hs.timer.delayed

API Overview

• Functions - API calls offered directly by the extension
• absolutetime
• days
• hours
• localTime
• minutes
• seconds
• secondsSinceEpoch
• usleep
• weeks
• Constructors - API calls which return an object, typically one that offers API methods
• doAfter
• doAt
• doEvery
• doUntil
• doWhile
• new
• waitUntil
• waitWhile
• Methods - API calls which can only be made on an object returned by a constructor
• fire
• nextTrigger
• running
• setNextTrigger
• start
• stop

API Documentation

Functions

absolutetime

Signature	hs.timer.absolutetime() -> nanoseconds
Type	Function
Description	Returns the absolute time in nanoseconds since the last system boot.
Parameters	None
Returns	the time since the last system boot in nanoseconds
Notes	this value does not include time that the system has spent asleep this value is used for the timestamps in system generated events.

days

Signature	hs.timer.days(n) -> sec
Type	Function
Description	Converts days to seconds
Parameters	n - A number of days
Returns	The number of seconds in n days

hours

Signature	hs.timer.hours(n) -> seconds
Type	Function
Description	Converts hours to seconds
Parameters	n - A number of hours
Returns	The number of seconds in n hours

localTime

Signature	hs.timer.localTime() -> number
Type	Function
Description	Returns the number of seconds since local time midnight
Parameters	None
Returns	the number of seconds

minutes

Signature	hs.timer.minutes(n) -> seconds
Type	Function
Description	Converts minutes to seconds
Parameters	n - A number of minutes
Returns	The number of seconds in n minutes

seconds

Signature	hs.timer.seconds(timeOrDuration) -> seconds
Type	Function
Description	Converts a string with a time of day or a duration into number of seconds
Parameters	timeOrDuration - a string that can have any of the following formats: "HH:MM:SS" or "HH:MM" - represents a time of day (24-hour clock), returns the number of seconds since midnight "DDdHHh", "HHhMMm", "MMmSSs", "DDd", "HHh", "MMm", "SSs", "NNNNms" - represents a duration in days, hours, minutes, seconds and/or milliseconds
Returns	The number of seconds

secondsSinceEpoch

Signature	hs.timer.secondsSinceEpoch() -> sec
Type	Function
Description	Gets the (fractional) number of seconds since the UNIX epoch (January 1, 1970)
Parameters	None
Returns	The number of seconds since the epoch
Notes	This has much better precision than os.time(), which is limited to whole seconds.

usleep

Signature	hs.timer.usleep(microsecs)
Type	Function
Description	Blocks Lua execution for the specified time
Parameters	microsecs - A number containing a time in microseconds to block for
Returns	None
Notes	Use of this function is strongly discouraged, as it blocks all main-thread execution in Hammerspoon. This means no hotkeys or events will be processed in that time, no GUI updates will happen, and no Lua will execute. This is only provided as a last resort, or for extremely short sleeps. For all other purposes, you really should be splitting up your code into multiple functions and calling hs.timer.doAfter()

weeks

Signature	hs.timer.weeks(n) -> sec
Type	Function
Description	Converts weeks to seconds
Parameters	n - A number of weeks
Returns	The number of seconds in n weeks

Constructors

doAfter

Signature	hs.timer.doAfter(sec, fn) -> timer
Type	Constructor
Description	Calls a function after a delay
Parameters	sec - A number of seconds to wait before calling the function fn - A function to call
Returns	An hs.timer object
Notes	There is no need to call :start() on the returned object, the timer will be already running. The callback can be cancelled by calling the :stop() method on the returned object before sec seconds have passed.

doAt

Signature	hs.timer.doAt(time[, repeatInterval], fn[, continueOnError]) -> timer
Type	Constructor
Description	Creates and starts a timer which will perform fn at the given (local) time and then (optionally) repeat it every interval.
Parameters	time - number of seconds after (local) midnight, or a string in the format "HH:MM" (24-hour local time), indicating the desired trigger time repeatInterval - (optional) number of seconds between triggers, or a string in the format "DDd", "DDdHHh", "HHhMMm", "HHh" or "MMm" indicating days, hours and/or minutes between triggers; if omitted or 0 the timer will trigger only once fn - a function to call every time the timer triggers continueOnError - an optional boolean flag, defaulting to false, which indicates that the timer should not be automatically stopped if the callback function results in an error.
Returns	a timer object
Notes	The timer can trigger up to 1 second early or late The first trigger will be set to the earliest occurrence given the repeatInterval; if that's omitted, and time is earlier than the current time, the timer will trigger the next day. If the repeated interval results in exactly 24 hours you can schedule regular jobs that will run at the expected time independently of when Hammerspoon was restarted/reloaded. E.g.: If it's 19:00, hs.timer.doAt("20:00",somefn) will set the timer 1 hour from now If it's 21:00, hs.timer.doAt("20:00",somefn) will set the timer 23 hours from now If it's 21:00, hs.timer.doAt("20:00","6h",somefn) will set the timer 5 hours from now (at 02:00) To run a job every hour on the hour from 8:00 to 20:00: for h=8,20 do hs.timer.doAt(h..":00","1d",runJob) end

doEvery

Signature	hs.timer.doEvery(interval, fn) -> timer
Type	Constructor
Description	Repeats fn every interval seconds.
Parameters	interval - A number of seconds between triggers fn - A function to call every time the timer triggers
Returns	An hs.timer object
Notes	This function is a shorthand for hs.timer.new(interval, fn):start()

doUntil

Signature	hs.timer.doUntil(predicateFn, actionFn[, checkInterval]) -> timer
Type	Constructor
Description	Creates and starts a timer which will perform actionFn every checkinterval seconds until predicateFn returns true. The timer is automatically stopped when predicateFn returns true.
Parameters	predicateFn - a function which determines when to stop calling actionFn. This function takes no arguments, but should return true when it is time to stop calling actionFn. actionFn - a function which performs the desired action. This function may take a single argument, the timer itself. checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns	a timer object
Notes	The timer is passed as an argument to actionFn so that it may stop the timer prematurely (i.e. before predicateFn returns true) if desired. See also hs.timer.doWhile, which is essentially the opposite of this function

doWhile

Signature	hs.timer.doWhile(predicateFn, actionFn[, checkInterval]) -> timer
Type	Constructor
Description	Creates and starts a timer which will perform actionFn every checkinterval seconds while predicateFn returns true. The timer is automatically stopped when predicateFn returns false.
Parameters	predicateFn - a function which determines when to stop calling actionFn. This function takes no arguments, but should return false when it is time to stop calling actionFn. actionFn - a function which performs the desired action. This function may take a single argument, the timer itself. checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns	a timer object
Notes	The timer is passed as an argument to actionFn so that it may stop the timer prematurely (i.e. before predicateFn returns false) if desired. See also hs.timer.doUntil, which is essentially the opposite of this function

new

Signature	hs.timer.new(interval, fn [, continueOnError]) -> timer
Type	Constructor
Description	Creates a new hs.timer object for repeating interval callbacks
Parameters	interval - A number of seconds between firings of the timer fn - A function to call every time the timer fires continueOnError - An optional boolean, true if the timer should continue to be triggered after the callback function has produced an error, false if the timer should stop being triggered after the callback function has produced an error. Defaults to false.
Returns	An hs.timer object
Notes	The returned object does not start its timer until its :start() method is called If interval is 0, the timer will not repeat (because if it did, it would be repeating as fast as your machine can manage, which seems generally unwise) For non-zero intervals, the lowest acceptable value for the interval is 0.00001s. Values >0 and <0.00001 will be coerced to 0.00001

waitUntil

Signature	hs.timer.waitUntil(predicateFn, actionFn[, checkInterval]) -> timer
Type	Constructor
Description	Creates and starts a timer which will perform actionFn when predicateFn returns true. The timer is automatically stopped when actionFn is called.
Parameters	predicateFn - a function which determines when actionFn should be called. This function takes no arguments, but should return true when it is time to call actionFn. actionFn - a function which performs the desired action. This function may take a single argument, the timer itself. checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns	a timer object
Notes	The timer is stopped before actionFn is called, but the timer is passed as an argument to actionFn so that the actionFn may restart the timer to be called again the next time predicateFn returns true. See also hs.timer.waitWhile, which is essentially the opposite of this function

waitWhile

Signature	hs.timer.waitWhile(predicateFn, actionFn[, checkInterval]) -> timer
Type	Constructor
Description	Creates and starts a timer which will perform actionFn when predicateFn returns false. The timer is automatically stopped when actionFn is called.
Parameters	predicateFn - a function which determines when actionFn should be called. This function takes no arguments, but should return false when it is time to call actionFn. actionFn - a function which performs the desired action. This function may take a single argument, the timer itself. checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns	a timer object
Notes	The timer is stopped before actionFn is called, but the timer is passed as an argument to actionFn so that the actionFn may restart the timer to be called again the next time predicateFn returns false. See also hs.timer.waitUntil, which is essentially the opposite of this function

Methods

fire

Signature	hs.timer:fire() -> timer
Type	Method
Description	Immediately fires a timer
Parameters	None
Returns	The hs.timer object
Notes	This cannot be used on a timer which has already stopped running

nextTrigger

Signature	hs.timer:nextTrigger() -> number
Type	Method
Description	Returns the number of seconds until the timer will next trigger
Parameters	None
Returns	A number containing the number of seconds until the next firing
Notes	The return value may be a negative integer in two circumstances: Hammerspoon's runloop is backlogged and is catching up on missed timer triggers The timer object is not currently running. In this case, the return value of this method is the number of seconds since the last firing (you can check if the timer is running or not, with hs.timer:running()

running

Signature	hs.timer:running() -> boolean
Type	Method
Description	Returns a boolean indicating whether or not the timer is currently running.
Parameters	None
Returns	A boolean value indicating whether or not the timer is currently running.

setNextTrigger

Signature	hs.timer:setNextTrigger(seconds) -> timer
Type	Method
Description	Sets the next trigger time of a timer
Parameters	seconds - A number of seconds after which to trigger the timer
Returns	The hs.timer object, or nil if an error occurred
Notes	If the timer is not already running, this will start it

start

Signature	hs.timer:start() -> timer
Type	Method
Description	Starts an hs.timer object
Parameters	None
Returns	The hs.timer object
Notes	The timer will not call the callback immediately, the timer will wait until it fires If the callback function results in an error, the timer will be stopped to prevent repeated error notifications (see the continueOnError parameter to hs.timer.new() to override this)

stop

Signature	hs.timer:stop() -> timer
Type	Method
Description	Stops an hs.timer object
Parameters	None
Returns	The hs.timer object