The following image can help to understand what I'm going to do.
I have ngFor directive, in the component A, for which I route a component B binding the i-th object as state. The component B can set/change the field values of the object i-th.
I would like that when the B component change the assigned i-th object, the function of component A is called in order to make action on the other objects inside the component A.
Is there a way/mechanism/architecture that allows to do this?
The object passed as state to component B is correctly modified, in fact the modification can be viewed by component A. I don't know how to do what was described above.
Thank you all.
CodePudding user response：
You need to use a subject and observable pattern also known as event bus.
This is a summary of how it works!
- First we create a subject in a service, a subject can emit any number of times.
- Second we convert the subject to an observable in the constructor this observable will serve as a listener for events.
- In the service we create an emit, which can we emitted anywhere in the angular application.
- So ideally we have a emit method that can be called from any method in angular and a listener observable that can be subscribed from anywhere.
- Also not, most important, we should always unsubscribe the subscription, when using this method as it will cause a
memory leak!!!!
Use case: Use this method when you need to communicate between routing, or between components that are very deeply nested from each other!