Function: debounce()
debounce(
func,wait?,options?):Function
Creates a debounced function that delays invoking func until after wait
milliseconds have elapsed since the last time the debounced function was
invoked, or until the next browser frame is drawn. The debounced function
comes with a cancel method to cancel delayed func invocations and a
flush method to immediately invoke them. Provide options to indicate
whether func should be invoked on the leading and/or trailing edge of the
wait timeout. The func is invoked with the last arguments provided to the
debounced function. Subsequent calls to the debounced function return the
result of the last func invocation.
Note: If leading and trailing options are true, func is
invoked on the trailing edge of the timeout only if the debounced function
is invoked more than once during the wait timeout.
If wait is 0 and leading is false, func invocation is deferred
until the next tick, similar to setTimeout with a timeout of 0.
If wait is omitted in an environment with requestAnimationFrame, func
invocation will be deferred until the next frame is drawn (typically about
16ms).
See David Corbacho's article
for details over the differences between debounce and throttle.
Parameters
• func: Function
The function to debounce.
• wait?: number
The number of milliseconds to delay; if omitted, requestAnimationFrame is
used (if available).
• options?
The options object.
• options.leading?: boolean
Specify invoking on the leading edge of the timeout.
• options.maxWait?: number
The maximum time func is allowed to be delayed before it's invoked.
• options.trailing?: boolean
Specify invoking on the trailing edge of the timeout.
Returns
Function
Returns the new debounced function.
Example
// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', debounce(calculateLayout, 150))
// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', debounce(sendMail, 300, {
'leading': true,
'trailing': false
}))
// Ensure `batchLog` is invoked once after 1 second of debounced calls.
const debounced = debounce(batchLog, 250, { 'maxWait': 1000 })
const source = new EventSource('/stream')
jQuery(source).on('message', debounced)
// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel)
// Check for pending invocations.
const status = debounced.pending() ? "Pending..." : "Ready"