Package com.vaadin.flow.signals.function

Interface SignalModifier<P extends @Nullable Object,C extends @Nullable Object>

Type Parameters:
P - the parent signal value type
C - the child (mapped) signal value type
All Superinterfaces:
Serializable
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface SignalModifier<P extends @Nullable Object,C extends @Nullable Object> extends Serializable
Modifies the parent signal value in place based on a new child value. Used with the ValueSignal.modifier(SignalModifier) helper method to create write callbacks for mutable value patterns.

This interface is used with mutable value patterns where changing the child value directly modifies the parent value instance rather than creating a new one.

Usage example with a Todo class: 

 class Todo {
     private String task;
     private boolean done;

     public String getTask() {
         return task;
     }

     public void setTask(String task) {
         this.task = task;
     }

     public boolean isDone() {
         return done;
     }

     public void setDone(boolean done) {
         this.done = done;
     }
 }

 ValueSignal<Todo> todoSignal = new ValueSignal<>(new Todo());
 textField.bindValue(todoSignal.map(Todo::getTask),
         todoSignal.modifier(Todo::setTask));
 checkbox.bindValue(todoSignal.map(Todo::isDone),
         todoSignal.modifier(Todo::setDone));
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    modify(P parentValue, C newChildValue)
    Modifies the parent value in place with the new child value.

  • Method Details

    • modify

      void modify(P parentValue, C newChildValue)
      Modifies the parent value in place with the new child value.
      Parameters:
      parentValue - the parent signal value to modify
      newChildValue - the new child value to apply