Vue.js/dist/compiler.common.js

'use strict';

var entities = require('entities');

/**
 * Convert a value to a string that is actually rendered.
 *
 * @param {*} val
 * @return {String}
 */

function renderString(val) {
  return val == null ? '' : typeof val === 'object' ? JSON.stringify(val, null, 2) : String(val);
}

/**
 * Make a map and return a function for checking if a key
 * is in that map.
 *
 * @param {String} str
 * @param {Boolean} expectsLowerCase
 * @return {Function}
 */

function makeMap(str, expectsLowerCase) {
  var map = Object.create(null);
  var list = str.split(',');
  for (var i = 0; i < list.length; i++) {
    map[list[i]] = true;
  }
  return expectsLowerCase ? function (val) {
    return map[val.toLowerCase()];
  } : function (val) {
    return map[val];
  };
}

/**
 * Check if a tag is a built-in tag.
 */

var isBuiltInTag = makeMap('slot,component,render,transition', true);

/**
 * Remove an item from an array
 *
 * @param {Array} arr
 * @param {*} item
 */

function remove(arr, item) {
  if (arr.length) {
    var index = arr.indexOf(item);
    if (index > -1) {
      return arr.splice(index, 1);
    }
  }
}

/**
 * Check whether the object has the property.
 *
 * @param {Object} obj
 * @param {String} key
 * @return {Boolean}
 */
var hasOwnProperty = Object.prototype.hasOwnProperty;
function hasOwn(obj, key) {
  return hasOwnProperty.call(obj, key);
}

/**
 * Check if value is primitive
 *
 * @param {*} value
 * @return {Boolean}
 */

function isPrimitive(value) {
  return typeof value === 'string' || typeof value === 'number';
}

/**
 * Create a cached version of a pure function.
 *
 * @param {Function} fn
 * @return {Function}
 */

function cached(fn) {
  var cache = Object.create(null);
  return function cachedFn(str) {
    var hit = cache[str];
    return hit || (cache[str] = fn(str));
  };
}

/**
 * Camelize a hyphen-delmited string.
 *
 * @param {String} str
 * @return {String}
 */

var camelizeRE = /-(\w)/g;
var camelize = cached(function (str) {
  return str.replace(camelizeRE, toUpper);
});

function toUpper(_, c) {
  return c ? c.toUpperCase() : '';
}

/**
 * Hyphenate a camelCase string.
 *
 * @param {String} str
 * @return {String}
 */

var hyphenateRE = /([a-z\d])([A-Z])/g;
var hyphenate = cached(function (str) {
  return str.replace(hyphenateRE, '$1-$2').toLowerCase();
});

/**
 * Simple bind, faster than native
 *
 * @param {Function} fn
 * @param {Object} ctx
 * @return {Function}
 */

function bind(fn, ctx) {
  return function (a) {
    var l = arguments.length;
    return l ? l > 1 ? fn.apply(ctx, arguments) : fn.call(ctx, a) : fn.call(ctx);
  };
}

/**
 * Convert an Array-like object to a real Array.
 *
 * @param {Array-like} list
 * @param {Number} [start] - start index
 * @return {Array}
 */

function toArray(list, start) {
  start = start || 0;
  var i = list.length - start;
  var ret = new Array(i);
  while (i--) {
    ret[i] = list[i + start];
  }
  return ret;
}

/**
 * Mix properties into target object.
 *
 * @param {Object} to
 * @param {Object} from
 */

function extend(to, from) {
  for (var key in from) {
    to[key] = from[key];
  }
  return to;
}

/**
 * Quick object check - this is primarily used to tell
 * Objects from primitive values when we know the value
 * is a JSON-compliant type.
 *
 * @param {*} obj
 * @return {Boolean}
 */

function isObject(obj) {
  return obj !== null && typeof obj === 'object';
}

/**
 * Strict object type check. Only returns true
 * for plain JavaScript objects.
 *
 * @param {*} obj
 * @return {Boolean}
 */

var toString = Object.prototype.toString;
var OBJECT_STRING = '[object Object]';
function isPlainObject(obj) {
  return toString.call(obj) === OBJECT_STRING;
}

/**
 * Array type check.
 *
 * @param {*} obj
 * @return {Boolean}
 */

var isArray = Array.isArray;

/**
 * Check if a string starts with $ or _
 *
 * @param {String} str
 * @return {Boolean}
 */

function isReserved(str) {
  var c = (str + '').charCodeAt(0);
  return c === 0x24 || c === 0x5F;
}

/**
 * Define a property.
 *
 * @param {Object} obj
 * @param {String} key
 * @param {*} val
 * @param {Boolean} [enumerable]
 */

function def(obj, key, val, enumerable) {
  Object.defineProperty(obj, key, {
    value: val,
    enumerable: !!enumerable,
    writable: true,
    configurable: true
  });
}

/**
 * Parse simple path.
 */

var bailRE = /[^\w\.]/;
function parsePath(path) {
  if (bailRE.test(path)) {
    return;
  } else {
    path = path.split('.');
    return function (obj) {
      for (var i = 0; i < path.length; i++) {
        if (!obj) return;
        obj = obj[path[i]];
      }
      return obj;
    };
  }
}

/* global MutationObserver */

// can we use __proto__?
var hasProto = '__proto__' in {};

// Browser environment sniffing
var inBrowser = typeof window !== 'undefined' && Object.prototype.toString.call(window) !== '[object Object]';

// UA sniffing for working around browser-specific quirks
var UA$1 = inBrowser && window.navigator.userAgent.toLowerCase();
var isIos = UA$1 && /(iphone|ipad|ipod|ios)/i.test(UA$1);
var isWechat = UA$1 && UA$1.indexOf('micromessenger') > 0;

/**
 * Defer a task to execute it asynchronously. Ideally this
 * should be executed as a microtask, so we leverage
 * MutationObserver if it's available, and fallback to
 * setTimeout(0).
 *
 * @param {Function} cb
 * @param {Object} ctx
 */

var nextTick = function () {
  var callbacks = [];
  var pending = false;
  var timerFunc;
  function nextTickHandler() {
    pending = false;
    var copies = callbacks.slice(0);
    callbacks = [];
    for (var i = 0; i < copies.length; i++) {
      copies[i]();
    }
  }

  /* istanbul ignore if */
  if (typeof MutationObserver !== 'undefined' && !(isWechat && isIos)) {
    var counter = 1;
    var observer = new MutationObserver(nextTickHandler);
    var textNode = document.createTextNode(counter);
    observer.observe(textNode, {
      characterData: true
    });
    timerFunc = function timerFunc() {
      counter = (counter + 1) % 2;
      textNode.data = counter;
    };
  } else {
    // webpack attempts to inject a shim for setImmediate
    // if it is used as a global, so we have to work around that to
    // avoid bundling unnecessary code.
    var context = inBrowser ? window : typeof global !== 'undefined' ? global : {};
    timerFunc = context.setImmediate || setTimeout;
  }
  return function (cb, ctx) {
    var func = ctx ? function () {
      cb.call(ctx);
    } : cb;
    callbacks.push(func);
    if (pending) return;
    pending = true;
    timerFunc(nextTickHandler, 0);
  };
}();

var Set$1 = void 0;
/* istanbul ignore if */
if (typeof Set !== 'undefined' && Set.toString().match(/native code/)) {
  // use native Set when available.
  Set$1 = Set;
} else {
  // a non-standard Set polyfill that only works with primitive keys.
  Set$1 = function _Set() {
    this.set = Object.create(null);
  };
  Set$1.prototype.has = function (key) {
    return this.set[key] !== undefined;
  };
  Set$1.prototype.add = function (key) {
    this.set[key] = 1;
  };
  Set$1.prototype.clear = function () {
    this.set = Object.create(null);
  };
}

var hasProxy = void 0;
var proxyHandlers = void 0;
var initProxy = void 0;
if (process.env.NODE_ENV !== 'production') {
  (function () {
    var allowedGlobals = makeMap('Infinity,undefined,NaN,isFinite,isNaN,' + 'parseFloat,parseInt,decodeURI,decodeURIComponent,encodeURI,encodeURIComponent,' + 'Math,Number,Date,Array,Object,Boolean,String,RegExp,Map,Set,JSON,Intl');

    hasProxy = typeof Proxy !== 'undefined' && Proxy.toString().match(/native code/);

    proxyHandlers = {
      has: function has(target, key) {
        var has = key in target;
        var isAllowedGlobal = allowedGlobals(key);
        if (!has && !isAllowedGlobal) {
          warn$1('Trying to access non-existent property "' + key + '" while rendering.', target);
        }
        return !isAllowedGlobal;
      }
    };

    initProxy = function initProxy(vm) {
      if (hasProxy) {
        vm._renderProxy = new Proxy(vm, proxyHandlers);
      } else {
        vm._renderProxy = vm;
      }
    };
  })();
}

var uid$2 = 0;

/**
 * A dep is an observable that can have multiple
 * directives subscribing to it.
 *
 * @constructor
 */

function Dep() {
  this.id = uid$2++;
  this.subs = [];
}

// the current target watcher being evaluated.
// this is globally unique because there could be only one
// watcher being evaluated at any time.
Dep.target = null;

/**
 * Add a directive subscriber.
 *
 * @param {Directive} sub
 */

Dep.prototype.addSub = function (sub) {
  this.subs.push(sub);
};

/**
 * Remove a directive subscriber.
 *
 * @param {Directive} sub
 */

Dep.prototype.removeSub = function (sub) {
  remove(this.subs, sub);
};

/**
 * Add self as a dependency to the target watcher.
 */

Dep.prototype.depend = function () {
  Dep.target.addDep(this);
};

/**
 * Notify all subscribers of a new value.
 */

Dep.prototype.notify = function () {
  // stablize the subscriber list first
  var subs = this.subs.slice();
  for (var i = 0, l = subs.length; i < l; i++) {
    subs[i].update();
  }
};

var config = {

  /**
   * Preserve whitespaces between elements.
   */

  preserveWhitespace: true,

  /**
   * Whether to suppress warnings.
   *
   * @type {Boolean}
   */

  silent: false,

  /**
   * Check if a tag is reserved so that it cannot be registered as a
   * component. This is platform-dependent and may be overwritten.
   */

  isReservedTag: function isReservedTag() {
    return false;
  },

  /**
   * Check if a tag is an unknown element.
   * Platform-dependent.
   */

  isUnknownElement: function isUnknownElement() {
    return false;
  },

  /**
   * List of asset types that a component can own.
   *
   * @type {Array}
   */

  _assetTypes: ['component', 'directive', 'transition'],

  /**
   * List of lifecycle hooks.
   *
   * @type {Array}
   */

  _lifecycleHooks: ['init', 'created', 'beforeMount', 'mounted', 'ready', 'beforeUpdate', 'updated', 'beforeDestroy', 'destroyed'],

  /**
   * Max circular updates allowed in a batcher flush cycle.
   */

  _maxUpdateCount: 100
};

// we have two separate queues: one for directive updates
// and one for user watcher registered via $watch().
// we want to guarantee directive updates to be called
// before user watchers so that when user watchers are
// triggered, the DOM would have already been in updated
// state.

var queueIndex;
var queue = [];
var userQueue = [];
var has = {};
var circular = {};
var waiting = false;
var internalQueueDepleted = false;

/**
 * Reset the batcher's state.
 */

function resetBatcherState() {
  queue = [];
  userQueue = [];
  has = {};
  circular = {};
  waiting = internalQueueDepleted = false;
}

/**
 * Flush both queues and run the watchers.
 */

function flushBatcherQueue() {
  queue.sort(queueSorter);
  runBatcherQueue(queue);
  internalQueueDepleted = true;
  runBatcherQueue(userQueue);
  resetBatcherState();
}

/**
 * Sort queue before flush.
 * This ensures components are updated from parent to child
 * so there will be no duplicate updates, e.g. a child was
 * pushed into the queue first and then its parent's props
 * changed.
 */

function queueSorter(a, b) {
  return a.id - b.id;
}

/**
 * Run the watchers in a single queue.
 *
 * @param {Array} queue
 */

function runBatcherQueue(queue) {
  // do not cache length because more watchers might be pushed
  // as we run existing watchers
  for (queueIndex = 0; queueIndex < queue.length; queueIndex++) {
    var watcher = queue[queueIndex];
    var id = watcher.id;
    has[id] = null;
    watcher.run();
    // in dev build, check and stop circular updates.
    if (process.env.NODE_ENV !== 'production' && has[id] != null) {
      circular[id] = (circular[id] || 0) + 1;
      if (circular[id] > config._maxUpdateCount) {
        warn$1('You may have an infinite update loop for watcher ' + 'with expression "' + watcher.expression + '"', watcher.vm);
        break;
      }
    }
  }
}

/**
 * Push a watcher into the watcher queue.
 * Jobs with duplicate IDs will be skipped unless it's
 * pushed when the queue is being flushed.
 *
 * @param {Watcher} watcher
 *   properties:
 *   - {Number} id
 *   - {Function} run
 */

function pushWatcher(watcher) {
  var id = watcher.id;
  if (has[id] == null) {
    if (internalQueueDepleted && !watcher.user) {
      // an internal watcher triggered by a user watcher...
      // let's run it immediately after current user watcher is done.
      userQueue.splice(queueIndex + 1, 0, watcher);
    } else {
      // push watcher into appropriate queue
      var q = watcher.user ? userQueue : queue;
      has[id] = q.length;
      q.push(watcher);
      // queue the flush
      if (!waiting) {
        waiting = true;
        nextTick(flushBatcherQueue);
      }
    }
  }
}

var uid$1 = 0;
var prevTarget = void 0;

/**
 * A watcher parses an expression, collects dependencies,
 * and fires callback when the expression value changes.
 * This is used for both the $watch() api and directives.
 *
 * @param {Vue} vm
 * @param {String|Function} expOrFn
 * @param {Function} cb
 * @param {Object} options
 *                 - {Array} filters
 *                 - {Boolean} twoWay
 *                 - {Boolean} deep
 *                 - {Boolean} user
 *                 - {Boolean} sync
 *                 - {Boolean} lazy
 *                 - {Function} [preProcess]
 *                 - {Function} [postProcess]
 * @constructor
 */

function Watcher(vm, expOrFn, cb, options) {
  // mix in options
  if (options) {
    extend(this, options);
  }
  var isFn = typeof expOrFn === 'function';
  this.vm = vm;
  vm._watchers.push(this);
  this.expression = expOrFn;
  this.cb = cb;
  this.id = ++uid$1; // uid for batching
  this.active = true;
  this.dirty = this.lazy; // for lazy watchers
  this.deps = [];
  this.newDeps = [];
  this.depIds = new Set$1();
  this.newDepIds = new Set$1();
  // parse expression for getter
  if (isFn) {
    this.getter = expOrFn;
  } else {
    this.getter = parsePath(expOrFn);
    if (!this.getter) {
      this.getter = function () {};
      process.env.NODE_ENV !== 'production' && warn$1('Failed watching path: ' + expOrFn + 'Watcher only accepts simple dot-delimited paths. ' + 'For full control, use a function instead.', vm);
    }
  }
  this.value = this.lazy ? undefined : this.get();
  // state for avoiding false triggers for deep and Array
  // watchers during vm._digest()
  this.queued = this.shallow = false;
}

/**
 * Evaluate the getter, and re-collect dependencies.
 */

Watcher.prototype.get = function () {
  this.beforeGet();
  var value = this.getter.call(this.vm, this.vm);
  // "touch" every property so they are all tracked as
  // dependencies for deep watching
  if (this.deep) {
    traverse(value);
  }
  this.afterGet();
  return value;
};

/**
 * Prepare for dependency collection.
 */

Watcher.prototype.beforeGet = function () {
  prevTarget = Dep.target;
  Dep.target = this;
};

/**
 * Add a dependency to this directive.
 *
 * @param {Dep} dep
 */

Watcher.prototype.addDep = function (dep) {
  var id = dep.id;
  if (!this.newDepIds.has(id)) {
    this.newDepIds.add(id);
    this.newDeps.push(dep);
    if (!this.depIds.has(id)) {
      dep.addSub(this);
    }
  }
};

/**
 * Clean up for dependency collection.
 */

Watcher.prototype.afterGet = function () {
  Dep.target = prevTarget;
  var i = this.deps.length;
  while (i--) {
    var dep = this.deps[i];
    if (!this.newDepIds.has(dep.id)) {
      dep.removeSub(this);
    }
  }
  var tmp = this.depIds;
  this.depIds = this.newDepIds;
  this.newDepIds = tmp;
  this.newDepIds.clear();
  tmp = this.deps;
  this.deps = this.newDeps;
  this.newDeps = tmp;
  this.newDeps.length = 0;
};

/**
 * Subscriber interface.
 * Will be called when a dependency changes.
 *
 * @param {Boolean} shallow
 */

Watcher.prototype.update = function (shallow) {
  if (this.lazy) {
    this.dirty = true;
  } else if (this.sync) {
    this.run();
  } else {
    // if queued, only overwrite shallow with non-shallow,
    // but not the other way around.
    this.shallow = this.queued ? shallow ? this.shallow : false : !!shallow;
    this.queued = true;
    pushWatcher(this);
  }
};

/**
 * Batcher job interface.
 * Will be called by the batcher.
 */

Watcher.prototype.run = function () {
  if (this.active) {
    var value = this.get();
    if (value !== this.value ||
    // Deep watchers and watchers on Object/Arrays should fire even
    // when the value is the same, because the value may
    // have mutated; but only do so if this is a
    // non-shallow update (caused by a vm digest).
    (isObject(value) || this.deep) && !this.shallow) {
      // set new value
      var oldValue = this.value;
      this.value = value;
      this.cb.call(this.vm, value, oldValue);
    }
    this.queued = this.shallow = false;
  }
};

/**
 * Evaluate the value of the watcher.
 * This only gets called for lazy watchers.
 */

Watcher.prototype.evaluate = function () {
  // avoid overwriting another watcher that is being
  // collected.
  var current = Dep.target;
  this.value = this.get();
  this.dirty = false;
  Dep.target = current;
};

/**
 * Depend on all deps collected by this watcher.
 */

Watcher.prototype.depend = function () {
  var i = this.deps.length;
  while (i--) {
    this.deps[i].depend();
  }
};

/**
 * Remove self from all dependencies' subcriber list.
 */

Watcher.prototype.teardown = function () {
  if (this.active) {
    // remove self from vm's watcher list
    // this is a somewhat expensive operation so we skip it
    // if the vm is being destroyed or is performing a v-for
    // re-render (the watcher list is then filtered by v-for).
    if (!this.vm._isBeingDestroyed && !this.vm._vForRemoving) {
      remove(this.vm._watchers, this);
    }
    var i = this.deps.length;
    while (i--) {
      this.deps[i].removeSub(this);
    }
    this.active = false;
    this.vm = this.cb = this.value = null;
  }
};

/**
 * Recrusively traverse an object to evoke all converted
 * getters, so that every nested property inside the object
 * is collected as a "deep" dependency.
 *
 * @param {*} val
 * @param {Set} seen
 */

var seenObjects = new Set$1();
function traverse(val, seen) {
  var i = void 0,
      keys = void 0,
      isA = void 0,
      isO = void 0;
  if (!seen) {
    seen = seenObjects;
    seen.clear();
  }
  isA = isArray(val);
  isO = isObject(val);
  if (isA || isO) {
    if (val.__ob__) {
      var depId = val.__ob__.dep.id;
      if (seen.has(depId)) {
        return;
      } else {
        seen.add(depId);
      }
    }
    if (isA) {
      i = val.length;
      while (i--) {
        traverse(val[i], seen);
      }
    } else if (isO) {
      keys = Object.keys(val);
      i = keys.length;
      while (i--) {
        traverse(val[keys[i]], seen);
      }
    }
  }
}

var arrayProto = Array.prototype;
var arrayMethods = Object.create(arrayProto)

/**
 * Intercept mutating methods and emit events
 */

;['push', 'pop', 'shift', 'unshift', 'splice', 'sort', 'reverse'].forEach(function (method) {
  // cache original method
  var original = arrayProto[method];
  def(arrayMethods, method, function mutator() {
    // avoid leaking arguments:
    // http://jsperf.com/closure-with-arguments
    var i = arguments.length;
    var args = new Array(i);
    while (i--) {
      args[i] = arguments[i];
    }
    var result = original.apply(this, args);
    var ob = this.__ob__;
    var inserted;
    switch (method) {
      case 'push':
        inserted = args;
        break;
      case 'unshift':
        inserted = args;
        break;
      case 'splice':
        inserted = args.slice(2);
        break;
    }
    if (inserted) ob.observeArray(inserted);
    // notify change
    ob.dep.notify();
    return result;
  });
});

var arrayKeys = Object.getOwnPropertyNames(arrayMethods);

/**
 * By default, when a reactive property is set, the new value is
 * also converted to become reactive. However when passing down props,
 * we don't want to force conversion because the value may be a nested value
 * under a frozen data structure. Converting it would defeat the optimization.
 */

var observerState = {
  shouldConvert: true
};

/**
 * Observer class that are attached to each observed
 * object. Once attached, the observer converts target
 * object's property keys into getter/setters that
 * collect dependencies and dispatches updates.
 *
 * @param {Array|Object} value
 * @constructor
 */

function Observer(value) {
  this.value = value;
  this.dep = new Dep();
  def(value, '__ob__', this);
  if (isArray(value)) {
    var augment = hasProto ? protoAugment : copyAugment;
    augment(value, arrayMethods, arrayKeys);
    this.observeArray(value);
  } else {
    this.walk(value);
  }
}

// Instance methods

/**
 * Walk through each property and convert them into
 * getter/setters. This method should only be called when
 * value type is Object.
 *
 * @param {Object} obj
 */

Observer.prototype.walk = function (obj) {
  for (var key in obj) {
    this.convert(key, obj[key]);
  }
};

/**
 * Observe a list of Array items.
 *
 * @param {Array} items
 */

Observer.prototype.observeArray = function (items) {
  for (var i = 0, l = items.length; i < l; i++) {
    observe(items[i]);
  }
};

/**
 * Convert a property into getter/setter so we can emit
 * the events when the property is accessed/changed.
 *
 * @param {String} key
 * @param {*} val
 */

Observer.prototype.convert = function (key, val) {
  defineReactive(this.value, key, val);
};

/**
 * Add an owner vm, so that when $set/$delete mutations
 * happen we can notify owner vms to proxy the keys and
 * digest the watchers. This is only called when the object
 * is observed as an instance's root $data.
 *
 * @param {Vue} vm
 */

Observer.prototype.addVm = function (vm) {
  (this.vms || (this.vms = [])).push(vm);
};

/**
 * Remove an owner vm. This is called when the object is
 * swapped out as an instance's $data object.
 *
 * @param {Vue} vm
 */

Observer.prototype.removeVm = function (vm) {
  remove(this.vms, vm);
};

// helpers

/**
 * Augment an target Object or Array by intercepting
 * the prototype chain using __proto__
 *
 * @param {Object|Array} target
 * @param {Object} src
 */

function protoAugment(target, src) {
  /* eslint-disable no-proto */
  target.__proto__ = src;
  /* eslint-enable no-proto */
}

/**
 * Augment an target Object or Array by defining
 * hidden properties.
 *
 * @param {Object|Array} target
 * @param {Object} proto
 */

function copyAugment(target, src, keys) {
  for (var i = 0, l = keys.length; i < l; i++) {
    var key = keys[i];
    def(target, key, src[key]);
  }
}

/**
 * Attempt to create an observer instance for a value,
 * returns the new observer if successfully observed,
 * or the existing observer if the value already has one.
 *
 * @param {*} value
 * @param {Vue} [vm]
 * @return {Observer|undefined}
 * @static
 */

function observe(value, vm) {
  if (!isObject(value)) {
    return;
  }
  var ob;
  if (hasOwn(value, '__ob__') && value.__ob__ instanceof Observer) {
    ob = value.__ob__;
  } else if (observerState.shouldConvert && (isArray(value) || isPlainObject(value)) && Object.isExtensible(value) && !value._isVue) {
    ob = new Observer(value);
  }
  if (ob && vm) {
    ob.addVm(vm);
  }
  return ob;
}

/**
 * Define a reactive property on an Object.
 *
 * @param {Object} obj
 * @param {String} key
 * @param {*} val
 */

function defineReactive(obj, key, val) {
  var dep = new Dep();

  var property = Object.getOwnPropertyDescriptor(obj, key);
  if (property && property.configurable === false) {
    return;
  }

  // cater for pre-defined getter/setters
  var getter = property && property.get;
  var setter = property && property.set;

  var childOb = observe(val);
  Object.defineProperty(obj, key, {
    enumerable: true,
    configurable: true,
    get: function reactiveGetter() {
      var value = getter ? getter.call(obj) : val;
      if (Dep.target) {
        dep.depend();
        if (childOb) {
          childOb.dep.depend();
        }
        if (isArray(value)) {
          for (var e, i = 0, l = value.length; i < l; i++) {
            e = value[i];
            e && e.__ob__ && e.__ob__.dep.depend();
          }
        }
      }
      return value;
    },
    set: function reactiveSetter(newVal) {
      var value = getter ? getter.call(obj) : val;
      if (newVal === value) {
        return;
      }
      if (setter) {
        setter.call(obj, newVal);
      } else {
        val = newVal;
      }
      childOb = observe(newVal);
      dep.notify();
    }
  });
}

/**
 * Set a property on an object. Adds the new property and
 * triggers change notification if the property doesn't
 * already exist.
 *
 * @param {Object} obj
 * @param {String} key
 * @param {*} val
 * @public
 */

function set(obj, key, val) {
  if (isArray(obj)) {
    return obj.splice(key, 1, val);
  }
  if (hasOwn(obj, key)) {
    obj[key] = val;
    return;
  }
  if (obj._isVue) {
    set(obj._data, key, val);
    return;
  }
  var ob = obj.__ob__;
  if (!ob) {
    obj[key] = val;
    return;
  }
  ob.convert(key, val);
  ob.dep.notify();
  if (ob.vms) {
    var i = ob.vms.length;
    while (i--) {
      var vm = ob.vms[i];
      proxy(vm, key);
      vm.$forceUpdate();
    }
  }
  return val;
}

function proxy(vm, key) {
  if (!isReserved(key)) {
    Object.defineProperty(vm, key, {
      configurable: true,
      enumerable: true,
      get: function proxyGetter() {
        return vm._data[key];
      },
      set: function proxySetter(val) {
        vm._data[key] = val;
      }
    });
  }
}

function unproxy(vm, key) {
  if (!isReserved(key)) {
    delete vm[key];
  }
}

function initState(vm) {
  vm._watchers = [];
  initProps(vm);
  initData(vm);
  initComputed(vm);
  initMethods(vm);
  initWatch(vm);
}

function initProps(vm) {
  var props = vm.$options.props;
  var propsData = vm.$options.propsData;
  if (props) {
    var keys = vm.$options.propKeys = Object.keys(props);
    var isRoot = !vm.$parent;
    // root instance props should be converted
    observerState.shouldConvert = isRoot;
    for (var i = 0; i < keys.length; i++) {
      var key = keys[i];
      defineReactive(vm, key, validateProp(vm, key, propsData));
    }
    observerState.shouldConvert = true;
  }
}

function initData(vm) {
  var data = vm.$options.data;
  data = vm._data = typeof data === 'function' ? data() : data || {};
  if (!isPlainObject(data)) {
    data = {};
    process.env.NODE_ENV !== 'production' && warn$1('data functions should return an object.', vm);
  }
  // proxy data on instance
  var keys = Object.keys(data);
  var i = keys.length;
  while (i--) {
    proxy(vm, keys[i]);
  }
  // observe data
  observe(data, vm);
}

function noop() {}

function initComputed(vm) {
  var computed = vm.$options.computed;
  if (computed) {
    for (var key in computed) {
      var userDef = computed[key];
      var def = {
        enumerable: true,
        configurable: true
      };
      if (typeof userDef === 'function') {
        def.get = makeComputedGetter(userDef, vm);
        def.set = noop;
      } else {
        def.get = userDef.get ? userDef.cache !== false ? makeComputedGetter(userDef.get, vm) : bind(userDef.get, vm) : noop;
        def.set = userDef.set ? bind(userDef.set, vm) : noop;
      }
      Object.defineProperty(vm, key, def);
    }
  }
}

function makeComputedGetter(getter, owner) {
  var watcher = new Watcher(owner, getter, null, {
    lazy: true
  });
  return function computedGetter() {
    if (watcher.dirty) {
      watcher.evaluate();
    }
    if (Dep.target) {
      watcher.depend();
    }
    return watcher.value;
  };
}

function initMethods(vm) {
  var methods = vm.$options.methods;
  if (methods) {
    for (var key in methods) {
      vm[key] = bind(methods[key], vm);
    }
  }
}

function initWatch(vm) {
  var watch = vm.$options.watch;
  if (watch) {
    for (var key in watch) {
      var handler = watch[key];
      if (isArray(handler)) {
        for (var i = 0; i < handler.length; i++) {
          createWatcher(vm, key, handler[i]);
        }
      } else {
        createWatcher(vm, key, handler);
      }
    }
  }
}

function createWatcher(vm, key, handler) {
  var options = void 0;
  if (isPlainObject(handler)) {
    options = handler;
    handler = handler.handler;
  }
  if (typeof handler === 'string') {
    handler = vm[handler];
  }
  vm.$watch(key, handler, options);
}

function stateMixin(Vue) {
  Object.defineProperty(Vue.prototype, '$data', {
    get: function get() {
      return this._data;
    },
    set: function set(newData) {
      if (newData !== this._data) {
        setData(this, newData);
      }
    }
  });

  Vue.prototype.$watch = function (fn, cb, options) {
    options = options || {};
    options.user = true;
    var watcher = new Watcher(this, fn, cb, options)