RoboBinding how does ViewModel know variable to return

Question

Lets examine a simple example from here: Here is a simple layout file with a textview binding:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:bind="http://robobinding.org/android">
<TextView
    bind:text="{hello}" />
    ...
<Button
    android:text="Say Hello"
    bind:onClick="sayHello"/>

and here is the view model for this layout:

 @org.robobinding.annotation.PresentationModel
public class PresentationModel implements HasPresentationModelChangeSupport {
    private String name;//how does framework now what to set name to ?
    public String getHello() {
        return name + ": hello Android MVVM(Presentation Model)!";
    }
    ...
    public void sayHello() {
        firePropertyChange("hello");
    }
}

my question is how does the viewModel know what name is ? it has not been set anywhere ? What if i had many variables like name2,name3 etc. how would it know what to bind ?

score 1 · Accepted Answer · answered Mar 17 '15 at 00:05

You should take a look to the entire source code

MVVM example

There is a getter and a setter in the presentation model class that manage the value of the name field with the two ways binding specified in the layout

        <EditText 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        bind:text="${name}"/>

If you have more variables you must provide a getter and setter for each one if you want to use two way binding.

RoboBinding how does ViewModel know variable to return

1 Answers1