Revisiting this topic: why is the Template Method pattern not acceptable to
accomplish this?
<script>
class Base {
constructor() {
this._beforeAction()
this._action()
this._afterAction()
}
_beforeAction(){
console.log(`Base._beforeAction()`)
}
_action(){
console.log(`Base._action()`)
}
_afterAction(){
console.log(`Base._afterAction()`)
}
}
class A extends Base {
_action(){
console.log(`A._action()`)
}
}
let a = new A()
// console reads:
// > Base._beforeAction()
// > A._action()
// > Base._afterAction()
</script>
/Michael
-----
Monday, February 11, 2019 10:34 PM Michael Haufe <[email protected]>
wrote:
> You can use a Proxy in the base class:
>
> <script>
> let handlerExample = {
> get(target, prop) {
> let feature = target[prop]
> return feature instanceof Function ?
> function () {
> console.log('Before call');
> let result = feature.apply(this, arguments)
> console.log('After call');
> return result
> }
> : feature
> }
> }
>
> class Base {
> constructor() {
> return new Proxy(this, handlerExample)
> }
> m1() { return "m1" }
> }
>
> class Sub extends Base {
> m1() { return `override ${super.m1()}` }
> m2() { return `m2` }
> }
>
> let base = new Base()
> console.log(base.m1())
>
> let sub = new Sub()
> console.log(sub.m1())
> console.log(sub.m2())
> </script>
>
> /Michael
On Fri, Feb 8, 2019 at 1:22 AM #!/JoePea <[email protected]> wrote:
> I many times find myself in cases where a base class wants to ensure that
> logic is always fired after the current method's execution, so that for
> example no matter in which order sub classes call the `super` method, the
> `super` method can still guarantee that logic fires after the whole stack of
> the same method in the class hierarchy.
> So what I can do now is use `Promise.resolve().then(() => { ... })` to
> schedule that logic for later, that way all the invocations of a `foo` method
> along the class hierarchy have all fired. But this means that other code can
> also fire before the next microtask.
> Is there some way to do it? If not, I wonder if some language feature for
> doing it would be possible?
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