大概2600-3600行
// $emit直接执行函数
Vue.prototype.$emit = function (event) {
var vm = this;
{
var lowerCaseEvent = event.toLowerCase();
if (lowerCaseEvent !== event && vm._events[lowerCaseEvent]) {
tip(
"Event \"" + lowerCaseEvent + "\" is emitted in component " +
(formatComponentName(vm)) + " but the handler is registered for \"" + event + "\". " +
"Note that HTML attributes are case-insensitive and you cannot use " +
"v-on to listen to camelCase events when using in-DOM templates. " +
"You should probably use \"" + (hyphenate(event)) + "\" instead of \"" + event + "\"."
);
}
}
var cbs = vm._events[event];
if (cbs) {
cbs = cbs.length > 1 ? toArray(cbs) : cbs;
var args = toArray(arguments, 1);
for (var i = 0, l = cbs.length; i < l; i++) {
try {
cbs[i].apply(vm, args);
} catch (e) {
handleError(e, vm, ("event handler for \"" + event + "\""));
}
}
}
return vm
};
}
/* */
/**
* Runtime helper for resolving raw children VNodes into a slot object.
*/
// 解决模板和组件中的slot,slot属性为空的自动清除
function resolveSlots (
children,
context
) {
var slots = {};
//
if (!children) {
return slots
}
for (var i = 0, l = children.length; i < l; i++) {
var child = children[i];
var data = child.data;
// 先清除slots属性
// remove slot attribute if the node is resolved as a Vue slot node
if (data && data.attrs && data.attrs.slot) {
delete data.attrs.slot;
}
// named slots should only be respected if the vnode was rendered in the
// same context.
if ((child.context === context || child.fnContext === context) &&
data && data.slot != null
) {
var name = data.slot;
var slot = (slots[name] || (slots[name] = []));
if (child.tag === 'template') {
slot.push.apply(slot, child.children || []);
} else {
slot.push(child);
}
} else {
(slots.default || (slots.default = [])).push(child);
}
}
// ignore slots that contains only whitespace
for (var name$1 in slots) {
if (slots[name$1].every(isWhitespace)) {
delete slots[name$1];
}
}
return slots
}
// 是否是空白组件
function isWhitespace (node) {
return (node.isComment && !node.asyncFactory) || node.text === ' '
}
// 解决scope-slot
function resolveScopedSlots (
fns, // see flow/vnode
res
) {
res = res || {};
for (var i = 0; i < fns.length; i++) {
if (Array.isArray(fns[i])) {
resolveScopedSlots(fns[i], res);
} else {
res[fns[i].key] = fns[i].fn;
}
}
return res
}
/* */
var activeInstance = null;
var isUpdatingChildComponent = false;
// 生命周期初始化
function initLifecycle (vm) {
var options = vm.$options;
var parent = options.parent;
//设置 parent,如果parent.$parent,即为parent
if (parent && !options.abstract) {
while (parent.$options.abstract && parent.$parent) {
parent = parent.$parent;
}
parent.$children.push(vm);
}
//设置$parent
vm.$parent = parent;
//设置$root
vm.$root = parent ? parent.$root : vm;
//设置$children
vm.$children = [];
//设置$refs
vm.$refs = {};
//设置_watcher,_inactive,_directInactive,_isMounted,_isDestroyed,_isBeingDestroyed属性，为生命周期做准备
vm._watcher = null;
vm._inactive = null;
vm._directInactive = false;
vm._isMounted = false;
vm._isDestroyed = false;
vm._isBeingDestroyed = false;
}
function lifecycleMixin (Vue) {
// 生命周期update在mounted之后执行
Vue.prototype._update = function (vnode, hydrating) {
var vm = this;
if (vm._isMounted) {
callHook(vm, 'beforeUpdate');
}
var prevEl = vm.$el;
var prevVnode = vm._vnode;
var prevActiveInstance = activeInstance;
activeInstance = vm;
vm._vnode = vnode;
// Vue.prototype.__patch__ is injected in entry points
// based on the rendering backend used.
if (!prevVnode) {
// initial render
vm.$el = vm.__patch__(
vm.$el, vnode, hydrating, false /* removeOnly */,
vm.$options._parentElm,
vm.$options._refElm
);
// no need for the ref nodes after initial patch
// this prevents keeping a detached DOM tree in memory (#5851)
vm.$options._parentElm = vm.$options._refElm = null;
} else {
// updates
vm.$el = vm.__patch__(prevVnode, vnode);
}
activeInstance = prevActiveInstance;
// update __vue__ reference
if (prevEl) {
prevEl.__vue__ = null;
}
if (vm.$el) {
vm.$el.__vue__ = vm;
}
// if parent is an HOC, update its $el as well
if (vm.$vnode && vm.$parent && vm.$vnode === vm.$parent._vnode) {
vm.$parent.$el = vm.$el;
}
// updated hook is called by the scheduler to ensure that children are
// updated in a parent's updated hook.
};
// 监听器跟新
Vue.prototype.$forceUpdate = function () {
var vm = this;
if (vm._watcher) {
vm._watcher.update();
}
};
// 组件销毁
Vue.prototype.$destroy = function () {
var vm = this;
if (vm._isBeingDestroyed) {
return
}
callHook(vm, 'beforeDestroy');
vm._isBeingDestroyed = true;
// remove self from parent
var parent = vm.$parent;
if (parent && !parent._isBeingDestroyed && !vm.$options.abstract) {
remove(parent.$children, vm);
}
// teardown watchers
if (vm._watcher) {
vm._watcher.teardown();
}
var i = vm._watchers.length;
while (i--) {
vm._watchers[i].teardown();
}
// remove reference from data ob
// frozen object may not have observer.
if (vm._data.__ob__) {
vm._data.__ob__.vmCount--;
}
// call the last hook...
vm._isDestroyed = true;
// invoke destroy hooks on current rendered tree
vm.__patch__(vm._vnode, null);
// fire destroyed hook
callHook(vm, 'destroyed');
// turn off all instance listeners.
vm.$off();
// remove __vue__ reference
if (vm.$el) {
vm.$el.__vue__ = null;
}
// release circular reference (#6759)
if (vm.$vnode) {
vm.$vnode.parent = null;
}
};
}
// 组件挂载，或先执行beforeMount,在挂载渲染，并监听
function mountComponent (
vm,
el,
hydrating
) {
vm.$el = el;
if (!vm.$options.render) {
vm.$options.render = createEmptyVNode;
{
/* istanbul ignore if */
if ((vm.$options.template && vm.$options.template.charAt(0) !== '#') ||
vm.$options.el || el) {
warn(
'You are using the runtime-only build of Vue where the template ' +
'compiler is not available. Either pre-compile the templates into ' +
'render functions, or use the compiler-included build.',
vm
);
} else {
warn(
'Failed to mount component: template or render function not defined.',
vm
);
}
}
}
callHook(vm, 'beforeMount');
var updateComponent;
/* istanbul ignore if */
if ("development" !== 'production' && config.performance && mark) {
updateComponent = function () {
var name = vm._name;
var id = vm._uid;
var startTag = "vue-perf-start:" + id;
var endTag = "vue-perf-end:" + id;
mark(startTag);
var vnode = vm._render();
mark(endTag);
measure(("vue " + name + " render"), startTag, endTag);
mark(startTag);
vm._update(vnode, hydrating);
mark(endTag);
measure(("vue " + name + " patch"), startTag, endTag);
};
} else {
updateComponent = function () {
vm._update(vm._render(), hydrating);
};
}
// we set this to vm._watcher inside the watcher's constructor
// since the watcher's initial patch may call $forceUpdate (e.g. inside child
// component's mounted hook), which relies on vm._watcher being already defined
new Watcher(vm, updateComponent, noop, null, true /* isRenderWatcher */);
hydrating = false;
// manually mounted instance, call mounted on self
// mounted is called for render-created child components in its inserted hook
if (vm.$vnode == null) {
vm._isMounted = true;
callHook(vm, 'mounted');
}
return vm
}
// 跟新子组件
function updateChildComponent (
vm,
propsData,
listeners,
parentVnode,
renderChildren
) {
{
isUpdatingChildComponent = true;
}
// determine whether component has slot children
// we need to do this before overwriting $options._renderChildren
var hasChildren = !!(
renderChildren || // has new static slots
vm.$options._renderChildren || // has old static slots
parentVnode.data.scopedSlots || // has new scoped slots
vm.$scopedSlots !== emptyObject // has old scoped slots
);
vm.$options._parentVnode = parentVnode;
vm.$vnode = parentVnode; // update vm's placeholder node without re-render
if (vm._vnode) { // update child tree's parent
vm._vnode.parent = parentVnode;
}
vm.$options._renderChildren = renderChildren;
// update $attrs and $listeners hash
// these are also reactive so they may trigger child update if the child
// used them during render
vm.$attrs = parentVnode.data.attrs || emptyObject;
vm.$listeners = listeners || emptyObject;
// update props
if (propsData && vm.$options.props) {
toggleObserving(false);
var props = vm._props;
var propKeys = vm.$options._propKeys || [];
for (var i = 0; i < propKeys.length; i++) {
var key = propKeys[i];
var propOptions = vm.$options.props; // wtf flow?
props[key] = validateProp(key, propOptions, propsData, vm);
}
toggleObserving(true);
// keep a copy of raw propsData
vm.$options.propsData = propsData;
}
// update listeners
listeners = listeners || emptyObject;
var oldListeners = vm.$options._parentListeners;
vm.$options._parentListeners = listeners;
updateComponentListeners(vm, listeners, oldListeners);
// resolve slots + force update if has children
if (hasChildren) {
vm.$slots = resolveSlots(renderChildren, parentVnode.context);
vm.$forceUpdate();
}
{
isUpdatingChildComponent = false;
}
}
// 是否处于激活状态
function isInInactiveTree (vm) {
while (vm && (vm = vm.$parent)) {
if (vm._inactive) { return true }
}
return false
}
// active周期，必须是使用kepp-alive的组件
function activateChildComponent (vm, direct) {
if (direct) {
vm._directInactive = false;
if (isInInactiveTree(vm)) {
return
}
} else if (vm._directInactive) {
return
}
if (vm._inactive || vm._inactive === null) {
vm._inactive = false;
for (var i = 0; i < vm.$children.length; i++) {
activateChildComponent(vm.$children[i]);
}
callHook(vm, 'activated');
}
}
// deactive周期，必须是使用kepp-alive的
function deactivateChildComponent (vm, direct) {
if (direct) {
vm._directInactive = true;
if (isInInactiveTree(vm)) {
return
}
}
if (!vm._inactive) {
vm._inactive = true;
for (var i = 0; i < vm.$children.length; i++) {
deactivateChildComponent(vm.$children[i]);
}
callHook(vm, 'deactivated');
}
}
// 生命周期回调
function callHook (vm, hook) {
// #7573 disable dep collection when invoking lifecycle hooks
pushTarget();
var handlers = vm.$options[hook];
if (handlers) {
for (var i = 0, j = handlers.length; i < j; i++) {
try {
handlers[i].call(vm);
} catch (e) {
handleError(e, vm, (hook + " hook"));
}
}
}
if (vm._hasHookEvent) {
vm.$emit('hook:' + hook);
}
popTarget();
}
/* */
// 最大跟新的时间间隔是100毫秒
var MAX_UPDATE_COUNT = 100;
var queue = [];
var activatedChildren = [];
var has = {};
var circular = {};
var waiting = false;
var flushing = false;
var index = 0;
/**
* Reset the scheduler's state.
*/
//重置时刻表状态，不知道干嘛的
function resetSchedulerState () {
index = queue.length = activatedChildren.length = 0;
has = {};
{
circular = {};
}
waiting = flushing = false;
}
/**
* Flush both queues and run the watchers.
*/
// 执行监听器watcher的回调
function flushSchedulerQueue () {
flushing = true;
var watcher, id;
// Sort queue before flush.
// This ensures that:
// 1. Components are updated from parent to child. (because parent is always
// created before the child)
// 2. A component's user watchers are run before its render watcher (because
// user watchers are created before the render watcher)
// 3. If a component is destroyed during a parent component's watcher run,
// its watchers can be skipped.
queue.sort(function (a, b) { return a.id - b.id; });
// do not cache length because more watchers might be pushed
// as we run existing watchers
for (index = 0; index < queue.length; index++) {
watcher = queue[index];
id = watcher.id;
has[id] = null;
watcher.run();
// in dev build, check and stop circular updates.
if ("development" !== 'production' && has[id] != null) {
circular[id] = (circular[id] || 0) + 1;
if (circular[id] > MAX_UPDATE_COUNT) {
warn(
'You may have an infinite update loop ' + (
watcher.user
? ("in watcher with expression \"" + (watcher.expression) + "\"")
: "in a component render function."
),
watcher.vm
);
break
}
}
}
// keep copies of post queues before resetting state
var activatedQueue = activatedChildren.slice();
var updatedQueue = queue.slice();
resetSchedulerState();
// call component updated and activated hooks
callActivatedHooks(activatedQueue);
callUpdatedHooks(updatedQueue);
// devtool hook
/* istanbul ignore if */
if (devtools && config.devtools) {
devtools.emit('flush');
}
}
// 执行updated周期
function callUpdatedHooks (queue) {
var i = queue.length;
while (i--) {
var watcher = queue[i];
var vm = watcher.vm;
if (vm._watcher === watcher && vm._isMounted) {
callHook(vm, 'updated');
}
}
}
/**
* Queue a kept-alive component that was activated during patch.
* The queue will be processed after the entire tree has been patched.
*/
function queueActivatedComponent (vm) {
// setting _inactive to false here so that a render function can
// rely on checking whether it's in an inactive tree (e.g. router-view)
vm._inactive = false;
activatedChildren.push(vm);
}
// 整个watcher数组执行actived
function callActivatedHooks (queue) {
for (var i = 0; i < queue.length; i++) {
queue[i]._inactive = true;
activateChildComponent(queue[i], true /* true */);
}
}
/**
* Push a watcher into the watcher queue.
* Jobs with duplicate IDs will be skipped unless it's
* pushed when the queue is being flushed.
*/
// 添加watcher,然后执行回调
function queueWatcher (watcher) {
var id = watcher.id;
if (has[id] == null) {
has[id] = true;
if (!flushing) {
queue.push(watcher);
} else {
// if already flushing, splice the watcher based on its id
// if already past its id, it will be run next immediately.
var i = queue.length - 1;
while (i > index && queue[i].id > watcher.id) {
i--;
}
queue.splice(i + 1, 0, watcher);
}
// queue the flush
if (!waiting) {
waiting = true;
nextTick(flushSchedulerQueue);
}
}
}
/* */
var uid$1 = 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.
*/
//申明一个watcher，设置众多自身属性
var Watcher = function Watcher (
vm,
expOrFn,
cb,
options,
isRenderWatcher
) {
// 设置vm属性
this.vm = vm;
//是否渲染的是否就开始监听
if (isRenderWatcher) {
vm._watcher = this;
}
// vm的_watchers添加自身
vm._watchers.push(this);
// options
if (options) {
this.deep = !!options.deep;
this.user = !!options.user;
this.lazy = !!options.lazy;
this.sync = !!options.sync;
} else {
this.deep = this.user = this.lazy = this.sync = false;
}
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();
this.newDepIds = new _Set();
this.expression = expOrFn.toString();
// parse expression for getter
// 设置watcher的getter
if (typeof expOrFn === 'function') {
this.getter = expOrFn;
} else {
this.getter = parsePath(expOrFn);
if (!this.getter) {
this.getter = function () {};
"development" !== 'production' && warn(
"Failed watching path: \"" + expOrFn + "\" " +
'Watcher only accepts simple dot-delimited paths. ' +
'For full control, use a function instead.',
vm
);
}
}
// 设置value属性，回调用原型上的get方法
this.value = this.lazy
? undefined
: this.get();
};
/**
* Evaluate the getter, and re-collect dependencies.
*/
Watcher.prototype.get = function get () {
//dep的target指向本watcher
pushTarget(this);
var value;
var vm = this.vm;
try {
// 调用getter
value = this.getter.call(vm, vm);
} catch (e) {
if (this.user) {
handleError(e, vm, ("getter for watcher \"" + (this.expression) + "\""));
} else {
throw e
}
} finally {
// "touch" every property so they are all tracked as
// dependencies for deep watching
// 如果深度监听，递归每个属性
if (this.deep) {
traverse(value);
}
// 将dep的target移除
popTarget();
// 清除依赖
this.cleanupDeps();
}
return value
};
/**
* Add a dependency to this directive.
*/
// 添加新的依赖
Watcher.prototype.addDep = function addDep (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.
*/
//清空新的依赖数组中没有的旧的依赖，
Watcher.prototype.cleanupDeps = function cleanupDeps () {
var this$1 = this;
var i = this.deps.length;
while (i--) {
var dep = this$1.deps[i];
if (!this$1.newDepIds.has(dep.id)) {
dep.removeSub(this$1);
}
}
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.
*/
// watcher执行run或者queueWatcher方法，都是执行watchers或者watchers队列的数组
Watcher.prototype.update = function update () {
/* istanbul ignore else */
if (this.lazy) {
this.dirty = true;
} else if (this.sync) {
this.run();
} else {
queueWatcher(this);
}
};
/**
* Scheduler job interface.
* Will be called by the scheduler.
*/
// 触发函数
Watcher.prototype.run = function run () {
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.
isObject(value) ||
this.deep
) {
// set new value
var oldValue = this.value;
this.value = value;
if (this.user) {
try {
this.cb.call(this.vm, value, oldValue);
} catch (e) {
handleError(e, this.vm, ("callback for watcher \"" + (this.expression) + "\""));
}
} else {
this.cb.call(this.vm, value, oldValue);
}
}
}
};
/**
* Evaluate the value of the watcher.
* This only gets called for lazy watchers.
*/
// 计算watcher 的value值，并且不再是脏数据
Watcher.prototype.evaluate = function evaluate () {
this.value = this.get();
this.dirty = false;
};
/**
* Depend on all deps collected by this watcher.
*/
// 触发依赖的depend方法
Watcher.prototype.depend = function depend () {
var this$1 = this;
var i = this.deps.length;
while (i--) {
this$1.deps[i].depend();
}
};
/**
* Remove self from all dependencies' subscriber list.
*/
// 清除监听
Watcher.prototype.teardown = function teardown () {
var this$1 = this;
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.
if (!this.vm._isBeingDestroyed) {
remove(this.vm._watchers, this);
}
var i = this.deps.length;
while (i--) {
this$1.deps[i].removeSub(this$1);
}
this.active = false;
}
};
/* */
// 属性设置
var sharedPropertyDefinition = {
enumerable: true,
configurable: true,
get: noop,
set: noop
};
// 不想说了，前面有了
function proxy (target, sourceKey, key) {
sharedPropertyDefinition.get = function proxyGetter () {
return this[sourceKey][key]
};
sharedPropertyDefinition.set = function proxySetter (val) {
this[sourceKey][key] = val;
};
Object.defineProperty(target, key, sharedPropertyDefinition);
}
// 初始化状态
function initState (vm) {
vm._watchers = [];
var opts = vm.$options;
// 初始化props
if (opts.props) { initProps(vm, opts.props); }
// 初始化方法
if (opts.methods) { initMethods(vm, opts.methods); }
// 初始化data,设置监听
if (opts.data) {
initData(vm);
} else {
observe(vm._data = {}, true /* asRootData */);
}
// 计算属性computed
if (opts.computed) { initComputed(vm, opts.computed); }
// 初始化watch
if (opts.watch && opts.watch !== nativeWatch) {
initWatch(vm, opts.watch);
}
}
// 初始化props
function initProps (vm, propsOptions) {
var propsData = vm.$options.propsData || {};
var props = vm._props = {};
// cache prop keys so that future props updates can iterate using Array
// instead of dynamic object key enumeration.
var keys = vm.$options._propKeys = [];
var isRoot = !vm.$parent;
// root instance props should be converted
if (!isRoot) {
toggleObserving(false);
}
var loop = function ( key ) {
keys.push(key);
var value = validateProp(key, propsOptions, propsData, vm);
/* istanbul ignore else */
{
var hyphenatedKey = hyphenate(key);
//如果confirg设置了该参数或者属性，不可以在用作组件传递的值
if (isReservedAttribute(hyphenatedKey) ||
config.isReservedAttr(hyphenatedKey)) {
warn(
("\"" + hyphenatedKey + "\" is a reserved attribute and cannot be used as component prop."),
vm
);
}
// 设置监听
defineReactive(props, key, value, function () {
if (vm.$parent && !isUpdatingChildComponent) {
warn(
"Avoid mutating a prop directly since the value will be " +
"overwritten whenever the parent component re-renders. " +
"Instead, use a data or computed property based on the prop's " +
"value. Prop being mutated: \"" + key + "\"",
vm
);
}
});
}
// static props are already proxied on the component's prototype
// during Vue.extend(). We only need to proxy props defined at
// instantiation here.
if (!(key in vm)) {
proxy(vm, "_props", key);
}
};
for (var key in propsOptions) loop( key );
toggleObserving(true);
}
// 初始化data
function initData (vm) {
var data = vm.$options.data;
data = vm._data = typeof data === 'function'
? getData(data, vm)
: data || {};
if (!isPlainObject(data)) {
data = {};
"development" !== 'production' && warn(
'data functions should return an object:\n' +
'https://vuejs.org/v2/guide/components.html#data-Must-Be-a-Function',
vm
);
}
// proxy data on instance
var keys = Object.keys(data);
var props = vm.$options.props;
var methods = vm.$options.methods;
var i = keys.length;
while (i--) {
var key = keys[i];
{
if (methods && hasOwn(methods, key)) {
warn(
("Method \"" + key + "\" has already been defined as a data property."),
vm
);
}
}
if (props && hasOwn(props, key)) {
"development" !== 'production' && warn(
"The data property \"" + key + "\" is already declared as a prop. " +
"Use prop default value instead.",
vm
);
} else if (!isReserved(key)) {
proxy(vm, "_data", key);
}
}
// observe data
observe(data, true /* asRootData */);
}
// 获取data,data被执行，就是getter嘛
function getData (data, vm) {
// #7573 disable dep collection when invoking data getters
pushTarget();
try {
return data.call(vm, vm)
} catch (e) {
handleError(e, vm, "data()");
return {}
} finally {
popTarget();
}
}
var computedWatcherOptions = { lazy: true };
// 初始化computed
function initComputed (vm, computed) {
// $flow-disable-line
var watchers = vm._computedWatchers = Object.create(null);
// computed properties are just getters during SSR
var isSSR = isServerRendering();
for (var key in computed) {
var userDef = computed[key];
var getter = typeof userDef === 'function' ? userDef : userDef.get;
if ("development" !== 'production' && getter == null) {
warn(
("Getter is missing for computed property \"" + key + "\"."),
vm
);
}
if (!isSSR) {
// create internal watcher for the computed property.
watchers[key] = new Watcher(
vm,
getter || noop,
noop,
computedWatcherOptions
);
}
// component-defined computed properties are already defined on the
// component prototype. We only need to define computed properties defined
// at instantiation here.
if (!(key in vm)) {
defineComputed(vm, key, userDef);
} else {
if (key in vm.$data) {
warn(("The computed property \"" + key + "\" is already defined in data."), vm);
} else if (vm.$options.props && key in vm.$options.props) {
warn(("The computed property \"" + key + "\" is already defined as a prop."), vm);
}
}
}
}
// 定义computed
function defineComputed (
target,
key,
userDef
) {
var shouldCache = !isServerRendering();
if (typeof userDef === 'function') {
sharedPropertyDefinition.get = shouldCache
? createComputedGetter(key)
: userDef;
sharedPropertyDefinition.set = noop;
} else {
sharedPropertyDefinition.get = userDef.get
? shouldCache && userDef.cache !== false
? createComputedGetter(key)
: userDef.get
: noop;
sharedPropertyDefinition.set = userDef.set
? userDef.set
: noop;
}
if ("development" !== 'production' &&
sharedPropertyDefinition.set === noop) {
sharedPropertyDefinition.set = function () {
warn(
("Computed property \"" + key + "\" was assigned to but it has no setter."),
this
);
};
}
Object.defineProperty(target, key, sharedPropertyDefinition);