1 | var toInteger = require('./toInteger');
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2 |
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3 | /** Error message constants. */
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4 | var FUNC_ERROR_TEXT = 'Expected a function';
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5 |
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6 | /**
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7 | * Creates a function that invokes `func`, with the `this` binding and arguments
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8 | * of the created function, while it's called less than `n` times. Subsequent
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9 | * calls to the created function return the result of the last `func` invocation.
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10 | *
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11 | * @static
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12 | * @memberOf _
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13 | * @since 3.0.0
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14 | * @category Function
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15 | * @param {number} n The number of calls at which `func` is no longer invoked.
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16 | * @param {Function} func The function to restrict.
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17 | * @returns {Function} Returns the new restricted function.
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18 | * @example
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19 | *
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20 | * jQuery(element).on('click', _.before(5, addContactToList));
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21 | * // => Allows adding up to 4 contacts to the list.
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22 | */
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23 | function before(n, func) {
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24 | var result;
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25 | if (typeof func != 'function') {
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26 | throw new TypeError(FUNC_ERROR_TEXT);
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27 | }
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28 | n = toInteger(n);
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29 | return function() {
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30 | if (--n > 0) {
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31 | result = func.apply(this, arguments);
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32 | }
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33 | if (n <= 1) {
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34 | func = undefined;
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35 | }
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36 | return result;
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37 | };
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38 | }
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39 |
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40 | module.exports = before;
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