javascript - 与隔离范围指令的绑定(bind)有时不在范围内

Question

所以我有一个带有隔离范围和controllerAs模式的指令。

    var directive = {
        restrict: 'E',
        scope: {
            something: '='
        },
        templateUrl: './App/directiveTemplate.html',
        controller: directiveController,
        controllerAs: 'vm',
        bindToController: true
    }

在 Controller 中，我使用返回 promise 的 $http 调用 REST 服务进行初始化。

 function directiveController(someService) {

    var vm = this;

    // Here vm.something is defined and bound to the appropriate model set where the directive is used

    init()

    function init() {
        return someService.getProducts()
        .then(productsReady);

        function productsReady(response) {
            vm.products = response;
            //find product using vm.something

            // here vm.something is undefined

           return vm.products;
        }
    }

问题是，如果我在 init() 方法 vm.something 定义之前断点，就像它应该的那样，但在 productsReady 中函数未定义。

这是正常行为吗？ promise 解析代码是否在不同的范围内？

Answer 1

使用$onInit Life-Cycle Hook保证绑定(bind)的时间:

 function directiveController(someService) {

    var vm = this;

    ̶i̶n̶i̶t̶(̶)̶

    this.$onInit = init;

    function init() {
        return someService.getProducts()
        .then(productsReady);

        function productsReady(data) {
            vm.products = data;

           return vm.products;
        }
    }

来自文档:

Initialization logic that relies on bindings being present should be put in the controller's $onInit() method, which is guaranteed to always be called after the bindings have been assigned.

.component('myComponent', {
  bindings: {value: '<'},
  controller: function() {
    this.$onInit = function() {
      // `this.value` will always be initialized,
      // regardless of the value of `preAssignBindingsEnabled`.
      this.doubleValue = this.value * 2;
    };
  }
})

— AngularJS Developer Guide - Migrating to V1.6 - $compile