Hi, a quick question. When does the function `Widg...

# kvision

[Tomas Kormanak]

Hi, a quick question. When does the function Widget.dispose() is called?

[Robert Jaros]

Simple answer - when the widget is no longer used.

[Robert Jaros]

There are a few cases:

[Tomas Kormanak]

By 'no longer used' you mean removed from DOM?

[Robert Jaros]

no

[Tomas Kormanak]

Removed from component hiearchy?

[Robert Jaros]

it depends :)

[Robert Jaros]

let me explain step by step :)

[Robert Jaros]

1. when a container is disposed all its children are disposed as well, so the whole tree under the container is disposed

[Robert Jaros]

2. disposing is only initiated by components used with state binding, which regenerate their content dynamically

[Robert Jaros]

3. the only exception is disposing Root container, which can be initiated by application hot reload or by some advanced components which use Root containers internally (e.g. Tabulator and React)

[Robert Jaros]

4. Disposed components are no longer usable and are no longer used (they should be garbage collected)

[Robert Jaros]

5. If you are creating your own containers, which create children components without using functionality inherited from SimplePanel you should override dispose() and dispose of your children manually.

[Robert Jaros]

The most important part is number 3. When using reactive state binding, your lambda builder is executed on every state change. Your components are recreated with new state but at the same time old tree of your components is disposed.

[Robert Jaros]

If you are not using reactive state, there is no need to dispose anything.

[Robert Jaros]

And disposing has nothing to do with DOM. Components can be attached and detached from the DOM many times.

[Tomas Kormanak]

Thank you, great explanation. I would put it in documentation.