import Watcher from '../../watcher'
import { compileAndLinkProps } from '../../compiler/index'
import Dep from '../../observer/dep'
import {
observe,
defineReactive
} from '../../observer/index'
import {
warn,
query,
hasOwn,
isReserved,
isPlainObject,
bind
} from '../../util/index'
export default function (Vue) {
/**
* Accessor for `$data` property, since setting $data
* requires observing the new object and updating
* proxied properties.
*/
Object.defineProperty(Vue.prototype, '$data', {
get () {
return this._data
},
set (newData) {
if (newData !== this._data) {
this._setData(newData)
}
}
})
/**
* Setup the scope of an instance, which contains:
* - observed data
* - computed properties
* - user methods
* - meta properties
*/
Vue.prototype._initState = function () {
this._initProps()
this._initMeta()
this._initMethods()
this._initData()
this._initComputed()
}
/**
* Initialize props.
*/
Vue.prototype._initProps = function () {
var options = this.$options
var el = options.el
var props = options.props
if (props && !el) {
process.env.NODE_ENV !== 'production' && warn(
'Props will not be compiled if no `el` option is ' +
'provided at instantiation.',
this
)
}
// make sure to convert string selectors into element now
el = options.el = query(el)
this._propsUnlinkFn = el && el.nodeType === 1 && props
// props must be linked in proper scope if inside v-for
? compileAndLinkProps(this, el, props, this._scope)
: null
}
/**
* Initialize the data.
*/
Vue.prototype._initData = function () {
var dataFn = this.$options.data
var data = this._data = dataFn ? dataFn() : {}
if (!isPlainObject(data)) {
data = {}
process.env.NODE_ENV !== 'production' && warn(
'data functions should return an object.',
this
)
}
var props = this._props
// proxy data on instance
var keys = Object.keys(data)
var i, key
i = keys.length
while (i--) {
key = keys[i]
// there are two scenarios where we can proxy a data key:
// 1. it's not already defined as a prop
// 2. it's provided via a instantiation option AND there are no
// template prop present
if (!props || !hasOwn(props, key)) {
this._proxy(key)
} else if (process.env.NODE_ENV !== 'production') {
warn(
'Data field "' + key + '" is already defined ' +
'as a prop. To provide default value for a prop, use the "default" ' +
'prop option; if you want to pass prop values to an instantiation ' +
'call, use the "propsData" option.',
this
)
}
}
// observe data
observe(data, this)
}
/**
* Swap the instance's $data. Called in $data's setter.
*
* @param {Object} newData
*/
Vue.prototype._setData = function (newData) {
newData = newData || {}
var oldData = this._data
this._data = newData
var keys, key, i
// unproxy keys not present in new data
keys = Object.keys(oldData)
i = keys.length
while (i--) {
key = keys[i]
if (!(key in newData)) {
this._unproxy(key)
}
}
// proxy keys not already proxied,
// and trigger change for changed values
keys = Object.keys(newData)
i = keys.length
while (i--) {
key = keys[i]
if (!hasOwn(this, key)) {
// new property
this._proxy(key)
}
}
oldData.__ob__.removeVm(this)
observe(newData, this)
this._digest()
}
/**
* Proxy a property, so that
* vm.prop === vm._data.prop
*
* @param {String} key
*/
Vue.prototype._proxy = function (key) {
if (!isReserved(key)) {
// need to store ref to self here
// because these getter/setters might
// be called by child scopes via
// prototype inheritance.
var self = this
Object.defineProperty(self, key, {
configurable: true,
enumerable: true,
get: function proxyGetter () {
return self._data[key]
},
set: function proxySetter (val) {
self._data[key] = val
}
})
}
}
/**
* Unproxy a property.
*
* @param {String} key
*/
Vue.prototype._unproxy = function (key) {
if (!isReserved(key)) {
delete this[key]
}
}
/**
* Force update on every watcher in scope.
*/
Vue.prototype._digest = function () {
for (var i = 0, l = this._watchers.length; i < l; i++) {
this._watchers[i].update(true) // shallow updates
}
}
/**
* Setup computed properties. They are essentially
* special getter/setters
*/
function noop () {}
Vue.prototype._initComputed = function () {
var computed = this.$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, this)
def.set = noop
} else {
def.get = userDef.get
? userDef.cache !== false
? makeComputedGetter(userDef.get, this)
: bind(userDef.get, this)
: noop
def.set = userDef.set
? bind(userDef.set, this)
: noop
}
Object.defineProperty(this, 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
}
}
/**
* Setup instance methods. Methods must be bound to the
* instance since they might be passed down as a prop to
* child components.
*/
Vue.prototype._initMethods = function () {
var methods = this.$options.methods
if (methods) {
for (var key in methods) {
this[key] = bind(methods[key], this)
}
}
}
/**
* Initialize meta information like $index, $key & $value.
*/
Vue.prototype._initMeta = function () {
var metas = this.$options._meta
if (metas) {
for (var key in metas) {
defineReactive(this, key, metas[key])
}
}
}
}
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