more simple debounce

Author: SergioCrisostomo

Docs/Types/Function.md

@@ -375,11 +375,12 @@ This method will return a new function that will be called only once per group o
 
 ### Syntax:
 
-	var debounceFn = myFn.debounce({delay: 100});
+	var debounceFn = myFn.debounce(delay, leading);
 
 ### Arguments:
 
-1. obj - (*mixed*) If this argument is a number it will use it as the *delay* timeout of the debounce. If this argument is a object it will allow more specific configuration. Leaving the argument empty will fall to default values.
+1. delay - (*number*, optional, defaults to 250ms) The delay to wait before a call to the debounced function can happen again.
+2. leading - (*boolean*, optional, defaults to false) If the call to the debounced function should happen in leading phase of group of calls or after.
 
 ### Returns:
 
@@ -394,29 +395,6 @@ This method will return a new function that will be called only once per group o
 	}
 	window.addEvent('scroll', getNewScrollPosition.debounce(500));
 
-	// send a Request to server with data from a search field
-	// 500ms after you stopped typing, to avoid one request per character
-	var input = document.getElement('input');
-	var request = new Request({
-		url: 'your.url',
-		onSuccess: function(response) {
-			$('res').set('html', response);
-		}
-	});
-
-	function fn(){
-		request.send({data: {value: this.value}});   
-	}
-
-	input.addEventListener('keyup', fn.debounce(500));
-
-
-### Options:
-
-* *delay* - The delay after which the debounce function is called. Defaults to 250ms.
-* *when* - When to fire the debounce call. Can be at beginning of group call (*early*), at end (*late*) or *both*. Defaults to *late*.
-* *once* - If *true* will call the function only once per event handler. Defaults to *false*.
-
 
 
 Deprecated Functions {#Deprecated-Functions}

Source/Types/Function.js

@@ -74,28 +74,32 @@ Function.implement({
 		return setInterval(this.pass((args == null ? [] : args), bind), periodical);
 	},
 
-	debounce: function(opts){
-		var timeout,
+	debounce: function(delay, leading){
+
+		// in case delay is omitted and `leading` is first argument
+		if (typeof delay == 'boolean'){
+			leading = delay;
+			delay = false;
+		}
+
+		var timeout, args, self,
 			fn = this,
-			fireOnce = 0;
-		if (typeof opts == 'number') opts = {delay: opts};
-		else opts = opts || {};
-		if (!opts.delay) opts.delay = 250;
+			callNow = leading;
+
+		var later = function(){
+			if (leading) callNow = true;
+			else fn.apply(self, args);
+			timeout = null;
+		};
 
 		return function(){
-			if (fireOnce == 2 && opts.when == 'both' || fireOnce && opts.when != 'both') return;
-			var self = this,
-				args = arguments,
-				callNow = !timeout && (opts.when == 'early' || opts.when == 'both');
-			var later = function(){
-				if (opts.when != 'early') fn.apply(self, args);
-				timeout = null;
-				if (opts.once) fireOnce = 2;
-			};
+			self = this;
+			args = arguments;
+
 			clearTimeout(timeout);
-			timeout = setTimeout(later, opts.delay);
+			timeout = setTimeout(later, delay || 250);
 			if (callNow) fn.apply(self, args);
-			if (opts.once && callNow) fireOnce = 1;
+			callNow = false;
 		};
 	}