Feature request for form level listeners

[JortRoelofs]

I would like to be able to listen to form events on a form-level basis, so that it's possible to listen to form actions such as onBlur from a single location. I am aware that it is technically possible to listen to onChange by subscribing to the form store state, but this is not possible for the other field actions, even though use cases exist where it's preferred to subscribe to onMount, onBlur and to a lesser extent onSubmit.

For this, I expect the the implementation to be relatively easy as the current listener implementation already covers most requirements. The FieldListenerFn already contains a fieldApi parameter so that it can easily be deduced which field fires an event, even on a form-level basis.

In order to implement this, I believe little more needs to be done than adding a listeners attribute to the FormOptions interface being of the FieldListeners type. Additionally, the form-level listeners events can be fired in their respective functions, for example for onChange in the FieldApi.setValue method:

  setValue = (updater: Updater<TData>, options?: UpdateMetaOptions) => {
    this.form.setFieldValue(this.name, updater as never, options)

    this.options.listeners?.onChange?.({
      value: this.state.value,
      fieldApi: this,
    })
    this.form.options.listeners?.onChange?.({
      value: this.state.value,
      fieldApi: this,
    })

    this.validate('change')
  }

If help is required to implement this feature I think I'd be able to contribute. I'm interested to hear whether this a useful feature for this library.

[JortRoelofs]

My apologies, I now realize a pull-request #1261 exists for this feature, which has some difficulties that haven't been solved yet. I suppose that it makes this discussion redundant.