Can widgets persist state?

[ketozhang]

So far, the examples on the README always take state data from something external (mouse over from some watcher, time from system clock, etc).

If I wanted my widget to print 1, 2, 3, 4, etc in a loop by storing some state variable, can we do that?

My use case is to store a renderable in the widget without the need to re-instantiate on every call to Widget::render(). Without this feature, Rich stuff like spinners and progress bars are very limited.

[ThatXliner]

Since it's just Python classes, can't you just take advantage of the fact that we have instance attributes? This is OOP at the core...

Or use Reactive

The Hover class is a custom widget which displays a panel containing the classic text "Hello World". The first line in the Hover class may seem a little mysterious at this point:

mouse_over = Reactive(False)

This adds a mouse_over attribute to your class which is a bool with a default of False. Adding attributes like this makes them reactive: any changes will result in the widget updating.

https://github.com/Textualize/textual#creating-widgets

[ketozhang]

Yes, as long as you're not overwriting any existing APIs, be careful about setting class attributes as mutable objects which are shared among instance, or extend Widget::__init__.

I guess my question was more about if Textual has set an API for storing state (e.g., setState() in React).

[igorfil]

Any further development on this discussion?

I really like Textual and would like to use it in my projects, however without clear handling of state if feels very limited.

For example, I would like to use Textual in an application. It runs a thread that loads some data and saves it as a state. Next, I'd like Textual to take that state and render. What's the Textual's way to do that?