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/**
* Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/>
* Build: `lodash modularize exports="node" -o ./compat/`
* Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/>
* Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE>
* Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
* Available under MIT license <http://lodash.com/license>
*/
var debounce = require('./debounce'),
isFunction = require('../objects/isFunction'),
isObject = require('../objects/isObject');
/** Used as an internal `_.debounce` options object */
var debounceOptions = {
'leading': false,
'maxWait': 0,
'trailing': false
};
/**
* Creates a function that, when executed, will only call the `func` function
* at most once per every `wait` milliseconds. Provide an options object to
* indicate that `func` should be invoked on the leading and/or trailing edge
* of the `wait` timeout. Subsequent calls to the throttled function will
* return the result of the last `func` call.
*
* Note: If `leading` and `trailing` options are `true` `func` will be called
* on the trailing edge of the timeout only if the the throttled function is
* invoked more than once during the `wait` timeout.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to throttle.
* @param {number} wait The number of milliseconds to throttle executions to.
* @param {Object} [options] The options object.
* @param {boolean} [options.leading=true] Specify execution on the leading edge of the timeout.
* @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout.
* @returns {Function} Returns the new throttled function.
* @example
*
* // avoid excessively updating the position while scrolling
* var throttled = _.throttle(updatePosition, 100);
* jQuery(window).on('scroll', throttled);
*
* // execute `renewToken` when the click event is fired, but not more than once every 5 minutes
* jQuery('.interactive').on('click', _.throttle(renewToken, 300000, {
* 'trailing': false
* }));
*/
function throttle(func, wait, options) {
var leading = true,
trailing = true;
if (!isFunction(func)) {
throw new TypeError;
}
if (options === false) {
leading = false;
} else if (isObject(options)) {
leading = 'leading' in options ? options.leading : leading;
trailing = 'trailing' in options ? options.trailing : trailing;
}
debounceOptions.leading = leading;
debounceOptions.maxWait = wait;
debounceOptions.trailing = trailing;
return debounce(func, wait, debounceOptions);
}
module.exports = throttle;