mirror of
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97 lines
3.5 KiB
JavaScript
97 lines
3.5 KiB
JavaScript
/**
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* lodash 3.0.4 (Custom Build) <https://lodash.com/>
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* Build: `lodash modern modularize exports="npm" -o ./`
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* Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
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* Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
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* Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
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* Available under MIT license <https://lodash.com/license>
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*/
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var debounce = require('lodash.debounce');
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/** Used as the `TypeError` message for "Functions" methods. */
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var FUNC_ERROR_TEXT = 'Expected a function';
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/**
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* Creates a throttled function that only invokes `func` at most once per
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* every `wait` milliseconds. The throttled function comes with a `cancel`
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* method to cancel delayed invocations. Provide an options object to indicate
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* that `func` should be invoked on the leading and/or trailing edge of the
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* `wait` timeout. Subsequent calls to the throttled function return the
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* result of the last `func` call.
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*
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* **Note:** If `leading` and `trailing` options are `true`, `func` is invoked
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* on the trailing edge of the timeout only if the the throttled function is
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* invoked more than once during the `wait` timeout.
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*
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* See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation)
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* for details over the differences between `_.throttle` and `_.debounce`.
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*
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* @static
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* @memberOf _
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* @category Function
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* @param {Function} func The function to throttle.
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* @param {number} [wait=0] The number of milliseconds to throttle invocations to.
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* @param {Object} [options] The options object.
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* @param {boolean} [options.leading=true] Specify invoking on the leading
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* edge of the timeout.
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* @param {boolean} [options.trailing=true] Specify invoking on the trailing
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* edge of the timeout.
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* @returns {Function} Returns the new throttled function.
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* @example
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*
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* // avoid excessively updating the position while scrolling
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* jQuery(window).on('scroll', _.throttle(updatePosition, 100));
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*
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* // invoke `renewToken` when the click event is fired, but not more than once every 5 minutes
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* jQuery('.interactive').on('click', _.throttle(renewToken, 300000, {
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* 'trailing': false
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* }));
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*
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* // cancel a trailing throttled call
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* jQuery(window).on('popstate', throttled.cancel);
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*/
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function throttle(func, wait, options) {
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var leading = true,
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trailing = true;
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if (typeof func != 'function') {
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throw new TypeError(FUNC_ERROR_TEXT);
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}
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if (options === false) {
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leading = false;
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} else if (isObject(options)) {
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leading = 'leading' in options ? !!options.leading : leading;
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trailing = 'trailing' in options ? !!options.trailing : trailing;
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}
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return debounce(func, wait, { 'leading': leading, 'maxWait': +wait, 'trailing': trailing });
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}
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/**
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* Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`.
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* (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
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*
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* @static
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* @memberOf _
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* @category Lang
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* @param {*} value The value to check.
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* @returns {boolean} Returns `true` if `value` is an object, else `false`.
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* @example
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*
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* _.isObject({});
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* // => true
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*
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* _.isObject([1, 2, 3]);
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* // => true
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*
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* _.isObject(1);
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* // => false
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*/
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function isObject(value) {
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// Avoid a V8 JIT bug in Chrome 19-20.
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// See https://code.google.com/p/v8/issues/detail?id=2291 for more details.
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var type = typeof value;
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return !!value && (type == 'object' || type == 'function');
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}
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module.exports = throttle;
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