Angular.js

'use strict';

/* We need to tell jshint what variables are being exported */
/* global angular: true,
  msie: true,
  jqLite: true,
  jQuery: true,
  slice: true,
  push: true,
  toString: true,
  ngMinErr: true,
  angularModule: true,
  uid: true,
  REGEX_STRING_REGEXP: true,
  VALIDITY_STATE_PROPERTY: true,

  lowercase: true,
  uppercase: true,
  manualLowercase: true,
  manualUppercase: true,
  nodeName_: true,
  isArrayLike: true,
  forEach: true,
  sortedKeys: true,
  forEachSorted: true,
  reverseParams: true,
  nextUid: true,
  setHashKey: true,
  extend: true,
  int: true,
  inherit: true,
  noop: true,
  identity: true,
  valueFn: true,
  isUndefined: true,
  isDefined: true,
  isObject: true,
  isString: true,
  isNumber: true,
  isDate: true,
  isArray: true,
  isFunction: true,
  isRegExp: true,
  isWindow: true,
  isScope: true,
  isFile: true,
  isBlob: true,
  isBoolean: true,
  isPromiseLike: true,
  trim: true,
  isElement: true,
  makeMap: true,
  size: true,
  includes: true,
  arrayRemove: true,
  isLeafNode: true,
  copy: true,
  shallowCopy: true,
  equals: true,
  csp: true,
  concat: true,
  sliceArgs: true,
  bind: true,
  toJsonReplacer: true,
  toJson: true,
  fromJson: true,
  startingTag: true,
  tryDecodeURIComponent: true,
  parseKeyValue: true,
  toKeyValue: true,
  encodeUriSegment: true,
  encodeUriQuery: true,
  angularInit: true,
  bootstrap: true,
  getTestability: true,
  snake_case: true,
  bindJQuery: true,
  assertArg: true,
  assertArgFn: true,
  assertNotHasOwnProperty: true,
  getter: true,
  getBlockNodes: true,
  hasOwnProperty: true,
  createMap: true,
*/

////////////////////////////////////

/**
 * @ngdoc module
 * @name ng
 * @module ng
 * @description
 *
 * # ng (core module)
 * The ng module is loaded by default when an AngularJS application is started. The module itself
 * contains the essential components for an AngularJS application to function. The table below
 * lists a high level breakdown of each of the services/factories, filters, directives and testing
 * components available within this core module.
 *
 * <div doc-module-components="ng"></div>
 */

var REGEX_STRING_REGEXP = /^\/(.+)\/([a-z]*)$/;

// The name of a form control's ValidityState property.
// This is used so that it's possible for internal tests to create mock ValidityStates.
var VALIDITY_STATE_PROPERTY = 'validity';

/**
 * @ngdoc function
 * @name angular.lowercase
 * @module ng
 * @kind function
 *
 * @description Converts the specified string to lowercase.
 * @param {string} string String to be converted to lowercase.
 * @returns {string} Lowercased string.
 */
var lowercase = function(string){return isString(string) ? string.toLowerCase() : string;};
var hasOwnProperty = Object.prototype.hasOwnProperty;

/**
 * @ngdoc function
 * @name angular.uppercase
 * @module ng
 * @kind function
 *
 * @description Converts the specified string to uppercase.
 * @param {string} string String to be converted to uppercase.
 * @returns {string} Uppercased string.
 */
var uppercase = function(string){return isString(string) ? string.toUpperCase() : string;};


var manualLowercase = function(s) {
  /* jshint bitwise: false */
  return isString(s)
      ? s.replace(/[A-Z]/g, function(ch) {return String.fromCharCode(ch.charCodeAt(0) | 32);})
      : s;
};
var manualUppercase = function(s) {
  /* jshint bitwise: false */
  return isString(s)
      ? s.replace(/[a-z]/g, function(ch) {return String.fromCharCode(ch.charCodeAt(0) & ~32);})
      : s;
};


// String#toLowerCase and String#toUpperCase don't produce correct results in browsers with Turkish
// locale, for this reason we need to detect this case and redefine lowercase/uppercase methods
// with correct but slower alternatives.
if ('i' !== 'I'.toLowerCase()) {
  lowercase = manualLowercase;
  uppercase = manualUppercase;
}


var /** holds major version number for IE or NaN for real browsers */
    msie,
    jqLite,           // delay binding since jQuery could be loaded after us.
    jQuery,           // delay binding
    slice             = [].slice,
    push              = [].push,
    toString          = Object.prototype.toString,
    ngMinErr          = minErr('ng'),

    /** @name angular */
    angular           = window.angular || (window.angular = {}),
    angularModule,
    uid               = 0;

/**
 * IE 11 changed the format of the UserAgent string.
 * See http://msdn.microsoft.com/en-us/library/ms537503.aspx
 */
msie = int((/msie (\d+)/.exec(lowercase(navigator.userAgent)) || [])[1]);
if (isNaN(msie)) {
  msie = int((/trident\/.*; rv:(\d+)/.exec(lowercase(navigator.userAgent)) || [])[1]);
}


/**
 * @private
 * @param {*} obj
 * @return {boolean} Returns true if `obj` is an array or array-like object (NodeList, Arguments,
 *                   String ...)
 */
function isArrayLike(obj) {
  if (obj == null || isWindow(obj)) {
    return false;
  }

  var length = obj.length;

  if (obj.nodeType === 1 && length) {
    return true;
  }

  return isString(obj) || isArray(obj) || length === 0 ||
         typeof length === 'number' && length > 0 && (length - 1) in obj;
}

/**
 * @ngdoc function
 * @name angular.forEach
 * @module ng
 * @kind function
 *
 * @description
 * Invokes the `iterator` function once for each item in `obj` collection, which can be either an
 * object or an array. The `iterator` function is invoked with `iterator(value, key, obj)`, where `value`
 * is the value of an object property or an array element, `key` is the object property key or
 * array element index and obj is the `obj` itself. Specifying a `context` for the function is optional.
 *
 * It is worth noting that `.forEach` does not iterate over inherited properties because it filters
 * using the `hasOwnProperty` method.
 *
   ```js
     var values = {name: 'misko', gender: 'male'};
     var log = [];
     angular.forEach(values, function(value, key) {
       this.push(key + ': ' + value);
     }, log);
     expect(log).toEqual(['name: misko', 'gender: male']);
   ```
 *
 * @param {Object|Array} obj Object to iterate over.
 * @param {Function} iterator Iterator function.
 * @param {Object=} context Object to become context (`this`) for the iterator function.
 * @returns {Object|Array} Reference to `obj`.
 */

function forEach(obj, iterator, context) {
  var key, length;
  if (obj) {
    if (isFunction(obj)) {
      for (key in obj) {
        // Need to check if hasOwnProperty exists,
        // as on IE8 the result of querySelectorAll is an object without a hasOwnProperty function
        if (key != 'prototype' && key != 'length' && key != 'name' && (!obj.hasOwnProperty || obj.hasOwnProperty(key))) {
          iterator.call(context, obj[key], key, obj);
        }
      }
    } else if (isArray(obj) || isArrayLike(obj)) {
      var isPrimitive = typeof obj !== 'object';
      for (key = 0, length = obj.length; key < length; key++) {
        if (isPrimitive || key in obj) {
          iterator.call(context, obj[key], key, obj);
        }
      }
    } else if (obj.forEach && obj.forEach !== forEach) {
        obj.forEach(iterator, context, obj);
    } else {
      for (key in obj) {
        if (obj.hasOwnProperty(key)) {
          iterator.call(context, obj[key], key, obj);
        }
      }
    }
  }
  return obj;
}

function sortedKeys(obj) {
  var keys = [];
  for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
      keys.push(key);
    }
  }
  return keys.sort();
}

function forEachSorted(obj, iterator, context) {
  var keys = sortedKeys(obj);
  for ( var i = 0; i < keys.length; i++) {
    iterator.call(context, obj[keys[i]], keys[i]);
  }
  return keys;
}


/**
 * when using forEach the params are value, key, but it is often useful to have key, value.
 * @param {function(string, *)} iteratorFn
 * @returns {function(*, string)}
 */
function reverseParams(iteratorFn) {
  return function(value, key) { iteratorFn(key, value); };
}

/**
 * A consistent way of creating unique IDs in angular.
 *
 * Using simple numbers allows us to generate 28.6 million unique ids per second for 10 years before
 * we hit number precision issues in JavaScript.
 *
 * Math.pow(2,53) / 60 / 60 / 24 / 365 / 10 = 28.6M
 *
 * @returns {number} an unique alpha-numeric string
 */
function nextUid() {
  return ++uid;
}


/**
 * Set or clear the hashkey for an object.
 * @param obj object
 * @param h the hashkey (!truthy to delete the hashkey)
 */
function setHashKey(obj, h) {
  if (h) {
    obj.$$hashKey = h;
  }
  else {
    delete obj.$$hashKey;
  }
}

/**
 * @ngdoc function
 * @name angular.extend
 * @module ng
 * @kind function
 *
 * @description
 * Extends the destination object `dst` by copying own enumerable properties from the `src` object(s)
 * to `dst`. You can specify multiple `src` objects.
 *
 * @param {Object} dst Destination object.
 * @param {...Object} src Source object(s).
 * @returns {Object} Reference to `dst`.
 */
function extend(dst) {
  var h = dst.$$hashKey;

  for (var i = 1, ii = arguments.length; i < ii; i++) {
    var obj = arguments[i];
    if (obj) {
      var keys = Object.keys(obj);
      for (var j = 0, jj = keys.length; j < jj; j++) {
        var key = keys[j];
        dst[key] = obj[key];
      }
    }
  }

  setHashKey(dst, h);
  return dst;
}

function int(str) {
  return parseInt(str, 10);
}


function inherit(parent, extra) {
  return extend(new (extend(function() {}, {prototype:parent}))(), extra);
}

/**
 * @ngdoc function
 * @name angular.noop
 * @module ng
 * @kind function
 *
 * @description
 * A function that performs no operations. This function can be useful when writing code in the
 * functional style.
   ```js
     function foo(callback) {
       var result = calculateResult();
       (callback || angular.noop)(result);
     }
   ```
 */
function noop() {}
noop.$inject = [];


/**
 * @ngdoc function
 * @name angular.identity
 * @module ng
 * @kind function
 *
 * @description
 * A function that returns its first argument. This function is useful when writing code in the
 * functional style.
 *
   ```js
     function transformer(transformationFn, value) {
       return (transformationFn || angular.identity)(value);
     };
   ```
 */
function identity($) {return $;}
identity.$inject = [];


function valueFn(value) {return function() {return value;};}

/**
 * @ngdoc function
 * @name angular.isUndefined
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is undefined.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is undefined.
 */
function isUndefined(value){return typeof value === 'undefined';}


/**
 * @ngdoc function
 * @name angular.isDefined
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is defined.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is defined.
 */
function isDefined(value){return typeof value !== 'undefined';}


/**
 * @ngdoc function
 * @name angular.isObject
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is an `Object`. Unlike `typeof` in JavaScript, `null`s are not
 * considered to be objects. Note that JavaScript arrays are objects.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is an `Object` but not `null`.
 */
function isObject(value){
  // http://jsperf.com/isobject4
  return value !== null && typeof value === 'object';
}


/**
 * @ngdoc function
 * @name angular.isString
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is a `String`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `String`.
 */
function isString(value){return typeof value === 'string';}


/**
 * @ngdoc function
 * @name angular.isNumber
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is a `Number`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `Number`.
 */
function isNumber(value){return typeof value === 'number';}


/**
 * @ngdoc function
 * @name angular.isDate
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a value is a date.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `Date`.
 */
function isDate(value) {
  return toString.call(value) === '[object Date]';
}


/**
 * @ngdoc function
 * @name angular.isArray
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is an `Array`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is an `Array`.
 */
var isArray = Array.isArray;

/**
 * @ngdoc function
 * @name angular.isFunction
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is a `Function`.
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `Function`.
 */
function isFunction(value){return typeof value === 'function';}


/**
 * Determines if a value is a regular expression object.
 *
 * @private
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a `RegExp`.
 */
function isRegExp(value) {
  return toString.call(value) === '[object RegExp]';
}


/**
 * Checks if `obj` is a window object.
 *
 * @private
 * @param {*} obj Object to check
 * @returns {boolean} True if `obj` is a window obj.
 */
function isWindow(obj) {
  return obj && obj.window === obj;
}


function isScope(obj) {
  return obj && obj.$evalAsync && obj.$watch;
}


function isFile(obj) {
  return toString.call(obj) === '[object File]';
}


function isBlob(obj) {
  return toString.call(obj) === '[object Blob]';
}


function isBoolean(value) {
  return typeof value === 'boolean';
}


function isPromiseLike(obj) {
  return obj && isFunction(obj.then);
}


var trim = function(value) {
  return isString(value) ? value.trim() : value;
};


/**
 * @ngdoc function
 * @name angular.isElement
 * @module ng
 * @kind function
 *
 * @description
 * Determines if a reference is a DOM element (or wrapped jQuery element).
 *
 * @param {*} value Reference to check.
 * @returns {boolean} True if `value` is a DOM element (or wrapped jQuery element).
 */
function isElement(node) {
  return !!(node &&
    (node.nodeName  // we are a direct element
    || (node.prop && node.attr && node.find)));  // we have an on and find method part of jQuery API
}

/**
 * @param str 'key1,key2,...'
 * @returns {object} in the form of {key1:true, key2:true, ...}
 */
function makeMap(str) {
  var obj = {}, items = str.split(","), i;
  for ( i = 0; i < items.length; i++ )
    obj[ items[i] ] = true;
  return obj;
}


function nodeName_(element) {
  return lowercase(element.nodeName || element[0].nodeName);
}


/**
 * @description
 * Determines the number of elements in an array, the number of properties an object has, or
 * the length of a string.
 *
 * Note: This function is used to augment the Object type in Angular expressions. See
 * {@link angular.Object} for more information about Angular arrays.
 *
 * @param {Object|Array|string} obj Object, array, or string to inspect.
 * @param {boolean} [ownPropsOnly=false] Count only "own" properties in an object
 * @returns {number} The size of `obj` or `0` if `obj` is neither an object nor an array.
 */
function size(obj, ownPropsOnly) {
  var count = 0, key;

  if (isArray(obj) || isString(obj)) {
    return obj.length;
  } else if (isObject(obj)) {
    for (key in obj)
      if (!ownPropsOnly || obj.hasOwnProperty(key))
        count++;
  }

  return count;
}


function includes(array, obj) {
  return Array.prototype.indexOf.call(array, obj) != -1;
}

function arrayRemove(array, value) {
  var index = array.indexOf(value);
  if (index >=0)
    array.splice(index, 1);
  return value;
}

function isLeafNode (node) {
  if (node) {
    switch (nodeName_(node)) {
    case "option":
    case "pre":
    case "title":
      return true;
    }
  }
  return false;
}

/**
 * @ngdoc function
 * @name angular.copy
 * @module ng
 * @kind function
 *
 * @description
 * Creates a deep copy of `source`, which should be an object or an array.
 *
 * * If no destination is supplied, a copy of the object or array is created.
 * * If a destination is provided, all of its elements (for array) or properties (for objects)
 *   are deleted and then all elements/properties from the source are copied to it.
 * * If `source` is not an object or array (inc. `null` and `undefined`), `source` is returned.
 * * If `source` is identical to 'destination' an exception will be thrown.
 *
 * @param {*} source The source that will be used to make a copy.
 *                   Can be any type, including primitives, `null`, and `undefined`.
 * @param {(Object|Array)=} destination Destination into which the source is copied. If
 *     provided, must be of the same type as `source`.
 * @returns {*} The copy or updated `destination`, if `destination` was specified.
 *
 * @example
 <example module="copyExample">
 <file name="index.html">
 <div ng-controller="ExampleController">
 <form novalidate class="simple-form">
 Name: <input type="text" ng-model="user.name" /><br />
 E-mail: <input type="email" ng-model="user.email" /><br />
 Gender: <input type="radio" ng-model="user.gender" value="male" />male
 <input type="radio" ng-model="user.gender" value="female" />female<br />
 <button ng-click="reset()">RESET</button>
 <button ng-click="update(user)">SAVE</button>
 </form>
 <pre>form = {{user | json}}</pre>
 <pre>master = {{master | json}}</pre>
 </div>

 <script>
  angular.module('copyExample', [])
    .controller('ExampleController', ['$scope', function($scope) {
      $scope.master= {};

      $scope.update = function(user) {
        // Example with 1 argument
        $scope.master= angular.copy(user);
      };

      $scope.reset = function() {
        // Example with 2 arguments
        angular.copy($scope.master, $scope.user);
      };

      $scope.reset();
    }]);
 </script>
 </file>
 </example>
 */
function copy(source, destination, stackSource, stackDest) {
  if (isWindow(source) || isScope(source)) {
    throw ngMinErr('cpws',
      "Can't copy! Making copies of Window or Scope instances is not supported.");
  }

  if (!destination) {
    destination = source;
    if (source) {
      if (isArray(source)) {
        destination = copy(source, [], stackSource, stackDest);
      } else if (isDate(source)) {
        destination = new Date(source.getTime());
      } else if (isRegExp(source)) {
        destination = new RegExp(source.source, source.toString().match(/[^\/]*$/)[0]);
        destination.lastIndex = source.lastIndex;
      } else if (isObject(source)) {
        var emptyObject = Object.create(Object.getPrototypeOf(source));
        destination = copy(source, emptyObject, stackSource, stackDest);
      }
    }
  } else {
    if (source === destination) throw ngMinErr('cpi',
      "Can't copy! Source and destination are identical.");

    stackSource = stackSource || [];
    stackDest = stackDest || [];

    if (isObject(source)) {
      var index = stackSource.indexOf(source);
      if (index !== -1) return stackDest[index];

      stackSource.push(source);
      stackDest.push(destination);
    }

    var result;
    if (isArray(source)) {
      destination.length = 0;
      for ( var i = 0; i < source.length; i++) {
        result = copy(source[i], null, stackSource, stackDest);
        if (isObject(source[i])) {
          stackSource.push(source[i]);
          stackDest.push(result);
        }
        destination.push(result);
      }
    } else {
      var h = destination.$$hashKey;
      if (isArray(destination)) {
        destination.length = 0;
      } else {
        forEach(destination, function(value, key) {
          delete destination[key];
        });
      }
      for ( var key in source) {
        if(source.hasOwnProperty(key)) {
          result = copy(source[key], null, stackSource, stackDest);
          if (isObject(source[key])) {
            stackSource.push(source[key]);
            stackDest.push(result);
          }
          destination[key] = result;
        }
      }
      setHashKey(destination,h);
    }

  }
  return destination;
}

/**
 * Creates a shallow copy of an object, an array or a primitive.
 *
 * Assumes that there are no proto properties for objects.
 */
function shallowCopy(src, dst) {
  if (isArray(src)) {
    dst = dst || [];

    for (var i = 0, ii = src.length; i < ii; i++) {
      dst[i] = src[i];
    }
  } else if (isObject(src)) {
    dst = dst || {};

    for (var key in src) {
      if (!(key.charAt(0) === '$' && key.charAt(1) === '$')) {
        dst[key] = src[key];
      }
    }
  }

  return dst || src;
}


/**
 * @ngdoc function
 * @name angular.equals
 * @module ng
 * @kind function
 *
 * @description
 * Determines if two objects or two values are equivalent. Supports value types, regular
 * expressions, arrays and objects.
 *
 * Two objects or values are considered equivalent if at least one of the following is true:
 *
 * * Both objects or values pass `===` comparison.
 * * Both objects or values are of the same type and all of their properties are equal by
 *   comparing them with `angular.equals`.
 * * Both values are NaN. (In JavaScript, NaN == NaN => false. But we consider two NaN as equal)
 * * Both values represent the same regular expression (In JavaScript,
 *   /abc/ == /abc/ => false. But we consider two regular expressions as equal when their textual
 *   representation matches).
 *
 * During a property comparison, properties of `function` type and properties with names
 * that begin with `$` are ignored.
 *
 * Scope and DOMWindow objects are being compared only by identify (`===`).
 *
 * @param {*} o1 Object or value to compare.
 * @param {*} o2 Object or value to compare.
 * @returns {boolean} True if arguments are equal.
 */
function equals(o1, o2) {
  if (o1 === o2) return true;
  if (o1 === null || o2 === null) return false;
  if (o1 !== o1 && o2 !== o2) return true; // NaN === NaN
  var t1 = typeof o1, t2 = typeof o2, length, key, keySet;
  if (t1 == t2) {
    if (t1 == 'object') {
      if (isArray(o1)) {
        if (!isArray(o2)) return false;
        if ((length = o1.length) == o2.length) {
          for(key=0; key<length; key++) {
            if (!equals(o1[key], o2[key])) return false;
          }
          return true;
        }
      } else if (isDate(o1)) {
        if (!isDate(o2)) return false;
        return equals(o1.getTime(), o2.getTime());
      } else if (isRegExp(o1) && isRegExp(o2)) {
        return o1.toString() == o2.toString();
      } else {
        if (isScope(o1) || isScope(o2) || isWindow(o1) || isWindow(o2) || isArray(o2)) return false;
        keySet = {};
        for(key in o1) {
          if (key.charAt(0) === '$' || isFunction(o1[key])) continue;
          if (!equals(o1[key], o2[key])) return false;
          keySet[key] = true;
        }
        for(key in o2) {
          if (!keySet.hasOwnProperty(key) &&
              key.charAt(0) !== '$' &&
              o2[key] !== undefined &&
              !isFunction(o2[key])) return false;
        }
        return true;
      }
    }
  }
  return false;
}

var csp = function() {
  if (isDefined(csp.isActive_)) return csp.isActive_;

  var active = !!(document.querySelector('[ng-csp]') ||
                  document.querySelector('[data-ng-csp]'));

  if (!active) {
    try {
      /* jshint -W031, -W054 */
      new Function('');
      /* jshint +W031, +W054 */
    } catch (e) {
      active = true;
    }
  }

  return (csp.isActive_ = active);
};



function concat(array1, array2, index) {
  return array1.concat(slice.call(array2, index));
}

function sliceArgs(args, startIndex) {
  return slice.call(args, startIndex || 0);
}


/* jshint -W101 */
/**
 * @ngdoc function
 * @name angular.bind
 * @module ng
 * @kind function
 *
 * @description
 * Returns a function which calls function `fn` bound to `self` (`self` becomes the `this` for
 * `fn`). You can supply optional `args` that are prebound to the function. This feature is also
 * known as [partial application](http://en.wikipedia.org/wiki/Partial_application), as
 * distinguished from [function currying](http://en.wikipedia.org/wiki/Currying#Contrast_with_partial_function_application).
 *
 * @param {Object} self Context which `fn` should be evaluated in.
 * @param {function()} fn Function to be bound.
 * @param {...*} args Optional arguments to be prebound to the `fn` function call.
 * @returns {function()} Function that wraps the `fn` with all the specified bindings.
 */
/* jshint +W101 */
function bind(self, fn) {
  var curryArgs = arguments.length > 2 ? sliceArgs(arguments, 2) : [];
  if (isFunction(fn) && !(fn instanceof RegExp)) {
    return curryArgs.length
      ? function() {
          return arguments.length
            ? fn.apply(self, curryArgs.concat(slice.call(arguments, 0)))
            : fn.apply(self, curryArgs);
        }
      : function() {
          return arguments.length
            ? fn.apply(self, arguments)
            : fn.call(self);
        };
  } else {
    // in IE, native methods are not functions so they cannot be bound (note: they don't need to be)
    return fn;
  }
}


function toJsonReplacer(key, value) {
  var val = value;

  if (typeof key === 'string' && key.charAt(0) === '$' && key.charAt(1) === '$') {
    val = undefined;
  } else if (isWindow(value)) {
    val = '$WINDOW';
  } else if (value &&  document === value) {
    val = '$DOCUMENT';
  } else if (isScope(value)) {
    val = '$SCOPE';
  }

  return val;
}


/**
 * @ngdoc function
 * @name angular.toJson
 * @module ng
 * @kind function
 *
 * @description
 * Serializes input into a JSON-formatted string. Properties with leading $$ characters will be
 * stripped since angular uses this notation internally.
 *
 * @param {Object|Array|Date|string|number} obj Input to be serialized into JSON.
 * @param {boolean=} pretty If set to true, the JSON output will contain newlines and whitespace.
 * @returns {string|undefined} JSON-ified string representing `obj`.
 */
function toJson(obj, pretty) {
  if (typeof obj === 'undefined') return undefined;
  return JSON.stringify(obj, toJsonReplacer, pretty ? '  ' : null);
}