Permalink
* lint files * added back arrow-paren and removed duplicate
| import debounce from './debounce.js' | |
| import isObject from './isObject.js' | |
| /** | |
| * Creates a throttled function that only invokes `func` at most once per | |
| * every `wait` milliseconds (or once per browser frame). The throttled 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 | |
| * throttled function. Subsequent calls to the throttled 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 throttled 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](https://css-tricks.com/debouncing-throttling-explained-examples/) | |
| * for details over the differences between `throttle` and `debounce`. | |
| * | |
| * @since 0.1.0 | |
| * @category Function | |
| * @param {Function} func The function to throttle. | |
| * @param {number} [wait=0] | |
| * The number of milliseconds to throttle invocations to; if omitted, | |
| * `requestAnimationFrame` is used (if available). | |
| * @param {Object} [options={}] The options object. | |
| * @param {boolean} [options.leading=true] | |
| * Specify invoking on the leading edge of the timeout. | |
| * @param {boolean} [options.trailing=true] | |
| * Specify invoking on the trailing edge of the timeout. | |
| * @returns {Function} Returns the new throttled function. | |
| * @example | |
| * | |
| * // Avoid excessively updating the position while scrolling. | |
| * jQuery(window).on('scroll', throttle(updatePosition, 100)) | |
| * | |
| * // Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes. | |
| * const throttled = throttle(renewToken, 300000, { 'trailing': false }) | |
| * jQuery(element).on('click', throttled) | |
| * | |
| * // Cancel the trailing throttled invocation. | |
| * jQuery(window).on('popstate', throttled.cancel) | |
| */ | |
| function throttle(func, wait, options) { | |
| let leading = true | |
| let trailing = true | |
| if (typeof func !== 'function') { | |
| throw new TypeError('Expected a function') | |
| } | |
| if (isObject(options)) { | |
| leading = 'leading' in options ? !!options.leading : leading | |
| trailing = 'trailing' in options ? !!options.trailing : trailing | |
| } | |
| return debounce(func, wait, { | |
| leading, | |
| trailing, | |
| 'maxWait': wait | |
| }) | |
| } | |
| export default throttle |