underscore.getSet.js

/**
 * @license
 * underscore.getSet 2.0.0
 * Copyright 2015 Clément Prévot <clementp at lumapps dot com>
 * Largely based on Lodash 3.10.1 <https://lodash.com/license>
 * Available under MIT license
 */
!function(root){
  'use strict';


  /**
   * Used as the [maximum length](http://ecma-international.org/ecma-262/6.0/#sec-number.max_safe_integer)
   * of an array-like value.
   */
  var MAX_SAFE_INTEGER = 9007199254740991;

  /** Used to match property names within property paths. */
  var reIsDeepProp = /\.|\[(?:[^[\]]*|(["'])(?:(?!\1)[^\n\\]|\\.)*?\1)\]/,
      reIsPlainProp = /^\w*$/,
      rePropName = /[^.[\]]+|\[(?:(-?\d+(?:\.\d+)?)|(["'])((?:(?!\2)[^\n\\]|\\.)*?)\2)\]/g;

  /** Used to match backslashes in property paths. */
  var reEscapeChar = /\\(\\)?/g;

  /** Used to detect unsigned integer values. */
  var reIsUint = /^\d+$/;


  // Defining helper functions
  /**
   * Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`.
   * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
   *
   * @static
   * @memberOf _
   * @category Lang
   * @param {*} value The value to check.
   * @returns {boolean} Returns `true` if `value` is an object, else `false`.
   * @example
   *
   * _.isObject({});
   * // => true
   *
   * _.isObject([1, 2, 3]);
   * // => true
   *
   * _.isObject(1);
   * // => false
   */
  function isObject(value) {
    // Avoid a V8 JIT bug in Chrome 19-20.
    // See https://code.google.com/p/v8/issues/detail?id=2291 for more details.
    var type = typeof value;
    return !!value && (type === 'object' || type === 'function');
  }

  /**
   * Checks if `value` is a property name and not a property path.
   *
   * @private
   * @param {*} value The value to check.
   * @param {Object} [object] The object to query keys on.
   * @returns {boolean} Returns `true` if `value` is a property name, else `false`.
   */
  function isKey(value, object) {
    var type = typeof value;
    if ((type === 'string' && reIsPlainProp.test(value)) || type === 'number') {
      return true;
    }
    if (Array.isArray(value)) {
      return false;
    }
    var result = !reIsDeepProp.test(value);
    return result || (object != null && value in toObject(object));
  }

  /**
   * Checks if `value` is a valid array-like index.
   *
   * @private
   * @param {*} value The value to check.
   * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
   * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
   */
  function isIndex(value, length) {
    value = (typeof value === 'number' || reIsUint.test(value)) ? +value : -1;
    length = length == null ? MAX_SAFE_INTEGER : length;
    return value > -1 && value % 1 === 0 && value < length;
  }

  /**
   * Converts `value` to an object if it's not one.
   *
   * @private
   * @param {*} value The value to process.
   * @returns {Object} Returns the object.
   */
  function toObject(value) {
    return isObject(value) ? value : Object(value);
  }

  /**
   * The base implementation of `get` without support for string paths
   * and default values.
   *
   * @private
   * @param {Object} object The object to query.
   * @param {Array} path The path of the property to get.
   * @param {string} [pathKey] The key representation of path.
   * @returns {*} Returns the resolved value.
   */
  function baseGet(object, path, pathKey) {
    if (object == null) {
      return;
    }
    if (pathKey !== undefined && pathKey in toObject(object)) {
      path = [pathKey];
    }
    var index = 0,
        length = path.length;

    while (object != null && index < length) {
      object = object[path[index++]];
    }
    return (index && index === length) ? object : undefined;
  }

  /**
   * Converts `value` to a string if it's not one. An empty string is returned
   * for `null` or `undefined` values.
   *
   * @private
   * @param {*} value The value to process.
   * @returns {string} Returns the string.
   */
  function baseToString(value) {
    return value == null ? '' : (value + '');
  }

  /**
   * Converts `value` to property path array if it's not one.
   *
   * @private
   * @param {*} value The value to process.
   * @returns {Array} Returns the property path array.
   */
  function toPath(value) {
    if (Array.isArray(value)) {
      return value;
    }
    var result = [];
    baseToString(value).replace(rePropName, function(match, number, quote, string) {
      result.push(quote ? string.replace(reEscapeChar, '$1') : (number || match));
    });
    return result;
  }


  // Defining underscore.getSet
  var gs = {
    VERSION: '2.0.0',

    get: function(object, path, defaultValue) {
      var result = object == null ? undefined : baseGet(object, toPath(path), (path + ''));
      return result === undefined ? defaultValue : result;
    },

    set: function(object, path, value) {
      if (object == null) {
        return object;
      }
      var pathKey = (path + '');
      path = (object[pathKey] != null || isKey(path, object)) ? [pathKey] : toPath(path);

      var index = -1,
          length = path.length,
          lastIndex = length - 1,
          nested = object;

      while (nested != null && ++index < length) {
        var key = path[index];
        if (isObject(nested)) {
          if (index === lastIndex) {
            nested[key] = value;
          } else if (nested[key] == null) {
            nested[key] = isIndex(path[index + 1]) ? [] : {};
          }
        }
        nested = nested[key];
      }
      return object;
    }
  };


  // Aliases


  // Exporting
  // CommonJS module is defined
  if (typeof exports !== 'undefined') {
    if (typeof module !== 'undefined' && module.exports)
    {
      module.exports = gs;
    }

    exports.gs = gs;
    exports._gs = gs;
  }


  // Register as a named module with AMD.
  if (typeof define === 'function' && define.amd)
  {
    define('underscore.getSet', [], function(){ return gs; });
  }


  // Integrate with Underscore.js if defined
  // or create our own underscore object.
  root._ = root._ || {};
  for (var functionName in gs) {
    if (gs.hasOwnProperty(functionName) && typeof gs[functionName] === 'function') {
      root._[functionName] = gs[functionName];
    }
  }
  root._.getSet = root._.gs = gs;
}(this);