Implement own debounce function for compatibility with Gravity Forms

Author: bfintal

lib/class-option-number.php

@@ -121,7 +121,27 @@ public static function createSliderScript() {
 					}
 				} ).disableSelection();
 			} );
-			$( '.tf-number input[type=number]' ).on( 'keyup', _.debounce( function() {
+
+			// Returns a function, that, as long as it continues to be invoked, will not
+			// be triggered. The function will be called after it stops being called for
+			// N milliseconds. If `immediate` is passed, trigger the function on the
+			// leading edge, instead of the trailing.
+			function debounce(func, wait, immediate) {
+				var timeout;
+				return function() {
+					var context = this, args = arguments;
+					var later = function() {
+						timeout = null;
+						if (!immediate) func.apply(context, args);
+					};
+					var callNow = immediate && !timeout;
+					clearTimeout(timeout);
+					timeout = setTimeout(later, wait);
+					if (callNow) func.apply(context, args);
+				};
+			};
+
+			$( '.tf-number input[type=number]' ).on( 'keyup', debounce( function() {
 				if ( $( this ).prev().slider( 'value' ).toString() !== $( this ).val().toString() ) {
 					$( this ).prev().slider( 'value', $( this ).val() );
 				}