Add firePhxChangeWhileComposing opt to live_socket

[nallwhy]

Through issue #3322, I observed the problem with Safari and IME composition for languages like Japanese, where firing phx-change during a composition session can cause unexpected behavior. However, for Korean input, the current behavior of skipping phx-change during composition introduces its own issues.

In Korean, even while composing, each intermediate character (e.g., 가) is considered a meaningful and complete character, even though it may later change to another (e.g., 각). As a result, treating intermediate characters as valid inputs and firing phx-change during composition is crucial for proper functionality. The current default behavior of skipping phx-change during isComposing does not align with the needs of Korean input users and would likely not be desirable for anyone using Korean.

To address this, I’ve added an explicit configuration option, opts.firePhxChangeWhileComposing, allowing developers to control whether phx-change should fire during composition sessions. While the default remains unchanged(�false), this option enables developers to adjust the behavior based on their application’s language and input requirements.

This change ensures greater flexibility for IME-based input scenarios, particularly for languages like Korean where the current behavior is problematic.

[SteffenDE]

Hey @nallwhy,

thank you very much for the contribution. I have no knowledge at all about how Koreans type, so this is very much appreciated. Can you please remove the changes to the assets in the priv folder? Those are built automatically once this is merged :)

[nallwhy]

@SteffenDE
Thank you for the feedback! I’ve removed the changes to the assets in the priv folder as you suggested.

[SteffenDE]

It would be nice if we were able to remove the special handling once Safari is fixed. The last question I have is: if you set the flag, isn’t compositing broken in Safari for Korean users?

[nallwhy]

It doesn’t cause any issues in Korean. Using the text as-is in the composing state is natural for Korean users.
Most Koreans would likely enable this option and use it by default.

[SteffenDE]

just a quick update here: Chris wanted to look into this a little more himself

[nallwhy]

Since this behavior has already been implemented, it may be difficult to change it for backward compatibility reasons. However, the best approach would be to provide an option to disable the trigger during composition. This would allow users to explicitly disable it only in specific cases, such as with the Japanese + Safari combination, while ensuring it works naturally in all other scenarios.