dependson.md

@DependsOn

Syntax

@DependsOn

Description

Target: getter method

Purpose: To notify change upon property's dependency.

It has the same function as @NotifyChange but with an inverse meaning. It is used to notify binder that getter method's target property is changed because one or more properties it depends on are changed. It can eliminate distributed @NotifyChange annotations in a ViewModel when a calculated property depends on multiple properties.

Example

public class FullnameViewModel {
    private String firstname;
    private String lastname;

    public String getFirstname() {
        return firstname;
    }
    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getLastname() {
        return lastname;
    }
    public void setLastname(String lastname) {
        this.lastname = lastname;
    }

    @DependsOn({"firstname", "lastname"})
    public String getFullname() {
        return (firstname == null ? "" : firstname) + " "
            + (lastname == null ? "" : lastname);
    }
}