ViewModel commit listener implementation

MyModel.kt

class MyModel : ItemViewModel<DomainType>() {
  
  // this will not be needed if the above solution is integrated to tornadofx.ViewModel
  // as the notifyCommitListeners() could be called by ViewModel.commit() method.
  override fun onCommit() {
        // TODO: notify listeners only when something really changed
        notifyCommitListeners()
    }
}

ViewModelExt.kt

package tornadofx.ext

import tornadofx.*


private val ViewModel.commitListeners by lazy { mutableListOf<() -> Unit>() }

// TODO: add commit listeners to specific properties
fun ViewModel.onCommit(op: () -> Unit) {
    this.commitListeners += op
}

//TODO: notify only listeners for specific properties
fun ViewModel.notifyCommitListeners() {
    commitListeners.forEach { it.invoke() }
}