Providing a onChange prop for <Field> should not overwrite the internal final-form onChange function

Are you submitting a bug report or a feature request?

bug report

What is the current behavior?

When passing my own onChange prop it actually overwrites the final-form onChange function.

What is the expected behavior?

When passing my own onChange function to the <Field> component it should merge with the internal onChange function of final-form

Sandbox Link

https://codesandbox.io/s/w7pl6pqkrw

Try to select a value in the second dropdown. It’ll fire the custom myOnChange function but won’t select the value because it overwrites the final-form onChange function.

What’s your environment?

"final-form": "^3.0.0",
"react-final-form": "^2.1.1",
"react": "16.2.0",
"react-dom": "16.2.0",

node version: v8.9.1

[mschipperheyn]

IMHO this is a totally valid request. I consider this a bug.

[felixjung]

Hi,

Thanks for submitting the issue and providing an example. I don’t have any working knowledge of the library, yet, other than reviewing the docs. However, looking at your suggestion, I don’t think this is a valid request. How would you expect the library to know how to compose (merge) your myOnChange with its own onChange? And, given that you basically overwrite the default onChange, I don’t think it should. But, your problem can be solved by using the render prop API for fields and providing your own onChange handler.

I’ve updated your example with the solution I have in mind: https://codesandbox.io/s/3qlx8o98j5

To the maintainers: this piece of software looks awesome and the docs are great! Thanks a lot!