projects/swimlane/ngx-datatable/src/lib/utils/throttle.ts
/**
* Throttle a function
*/
export function throttle(func: any, wait: number, options?: any) {
options = options || {};
let context: any;
let args: any;
let result: any;
let timeout: any = null;
let previous = 0;
function later() {
previous = options.leading === false ? 0 : +new Date();
timeout = null;
result = func.apply(context, args);
}
return function (this: any) {
const now = +new Date();
if (!previous && options.leading === false) {
previous = now;
}
const remaining = wait - (now - previous);
context = this;
args = arguments;
if (remaining <= 0) {
clearTimeout(timeout);
timeout = null;
previous = now;
result = func.apply(context, args);
} else if (!timeout && options.trailing !== false) {
timeout = setTimeout(later, remaining);
}
return result;
};
}
/**
* Throttle decorator
*
* class MyClass {
* throttleable(10)
* myFn() { ... }
* }
*/
export function throttleable(duration: number, options?: any) {
return function innerDecorator(target: any, key: PropertyKey, descriptor: PropertyDescriptor) {
return {
configurable: true,
enumerable: descriptor.enumerable,
get: function getter() {
Object.defineProperty(this, key, {
configurable: true,
enumerable: descriptor.enumerable,
value: throttle(descriptor.value, duration, options)
});
return this[key];
}
};
};
}