Function loop

vue.js:4908–4956

(key)

            toggleObserving(false);
        }
        var loop = function (key) {
            keys.push(key);
            /*
             验证支柱  验证 prosp 是否是规范数据 并且为props 添加 value.__ob__  属性，把prosp添加到观察者中
             *  校验 props 参数 就是组建 定义的props 类型数据，校验类型
             *
             * 判断prop.type的类型是不是Boolean或者String，如果不是他们两类型，调用getPropDefaultValue获取默认值并且把value添加到观察者模式中
             */
            var value = validateProp(
                key, //props 对象的key
                propsOptions,
                propsData,
                vm
            );
            /* istanbul ignore else 伊斯坦布尔忽略其他 */
            {
                //大写字母，加完减号又转成小写了 比如把驼峰 aBc 变成了 a-bc
                //匹配大写字母并且两面不是空白的 替换成 - 在转换成小写
                var hyphenatedKey = hyphenate(key);
                // 检查属性是否为保留属性。
                //var isReservedAttribute = makeMap('key,ref,slot,slot-scope,is');
                if (isReservedAttribute(hyphenatedKey) ||
                    config.isReservedAttr(hyphenatedKey)) {
                    //输出警告
                    warn(
                        ("\"" + hyphenatedKey + "\" is a reserved attribute and cannot be used as component prop."),
                        vm
                    );
                }
                //通过defineProperty的set方法去通知notify()订阅者subscribers有新的值修改
                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)) { //如果vm中没有props属性，则把他添加到vm中，这样组件this.[propsKey] 就可以获取到值了
                proxy(vm, "_props", key);
            }
        };
        //循环校验 props 是否 是合格数据 并且添加观察者
        for (var key in propsOptions) loop(key);
        toggleObserving(true);