从父级调用子小部件中的方法

Question

I have a method in my parent widget that runs and updates a boolean. Whenever the value is changed, a method needs to be run in a child widget, using the changed value. What is the best way to trigger that action from the parent?

Both widgets are stateful widgets.

Answer 1

You could either inject the parent's method as a callback to the child or dispatch a notification from the child and then listen for it in the parent.

The latter is a cleaner and more reusable way, since it'll improve your child reusability.

You can check here for a very good guide on how to do it!

Answer 2

The answer from magicleon94 was pretty good, and would have worked if I needed to update a widget with new information. I will probably reference that for some other issues I am working on. For this issue, I needed to run a method to return markers for a mapWidget, based on data from a parent, when that data changed. I found the best way to do that was using a streamController, as outlined by this StackOverflow post . Whenever I updated the value, I called add on the stream, and then received the update in my child class.