将绑定应用于控制器后是否发出Angular $ scope事件？

Question

I'm using a directive in an Angular (1.4) application that uses the bindToController option . Here's my directive definition (written in TypeScript):

export class MyDirective implements ng.IDirective {
    public restrict = 'E';
    public templateUrl = 'path/to/my/template.html';
    public controller = 'MyController';
    public controllerAs = 'vm';
    public bindToController = true;
    public scope = {
        myScopeProperty: '@'
    };
}

This is working as expected - the myScopeProperty property is correctly bound to the controller. However, this binding process happens after the object is constructed, which means I can't perform any logic that depends on the value of this bound property while the object is being constructed. For example (again, in TypeScript):

export class MyController {

    public myScopeProperty;

    constructor() {

        // this logs "undefined", even if the my-scope-property 
        // attribute on the directive has a value
        console.log('myScopeProperty: ' + this.myScopeProperty); 
    }
}

Is there a $scope event I can listen to inside this controller object that is fired after Angular has finished applying its initial binding values to this object?

Answer 1

There is no such event and there's none should be, because one-way @ binding means that myScopeProperty value may be updated multiple times.

$scope.$watch('vm.myScopeProperty', () => { ... }));

is the recommended way to watch for binding changes.

$timeout(() => { ... });

or $onInit controller hook (polyfillable in 1.4. with angular-component ) may be used to to postpone the code to a time when myScopeProperty has been already interpolated (the first time).