Composing widgets (which begin with liftEffect)

[jonathanlking]

If I run example 1 <> example 2 we get "example1" and "example2" logged to the console, however only the "example2" button is rendered to the DOM.

example :: forall a. Int -> Widget HTML a
example x = do
  liftEffect (log $ "example" <> show x)
  _ <- button [onClick] [text $ "example" <> show x]
  example’ x

This is not what I expect - I think both buttons should still be rendered. Could you confirm what the correct behaviour should be?

Interestingly moving the logging to after the button click results in both buttons being rendered. I've made a runnable gist that demonstrates this.

[ajnsit]

Yeah the current behaviour is buggy. I'm on it.

[ajnsit]

Okay @jonathanlking, I think this should be fixed now. It was happening because purescript-aff tries to be helpful and resolves aff actions synchronously whenever possible. I now detect that condition and handle it correctly.

Please let me know if it works for you now. Please feel free to reopen if it doesn't work as expected.

[jonathanlking]

Hmm, so running the example from the gist I get both logging, but now neither rendering and a console error: FAILED! TypeError: Cannot read property 'run' of undefined

Did you get this example working? Also thanks for responding and working on a fix so quickly, I really appreciate it!

[ajnsit]

Weird, I thought I tested it and it was working, but I may have had other code changes which got lost. Reopening this.

[ajnsit]

@jonathanlking Can you test out the fix now? I think I now handle the synchronous cases correctly. I also tested the code from your snippet and it seems to work.

[jonathanlking]

Yes, it looks good to me now too! Thank you so much for this incredible library and amazing support! 🎉

[ajnsit]

Glad to hear it! Thanks for reporting the issue!