Complex Type Conversion in Snippet Example

This tutorial shows you how to use a custom object in Snippet Lib.

This example assumes basic familiarity with Snippet Lib as demonstrated in Example 1.

Tutorial

1. Use Android Studio to create a new app project, similar to Example 1.

2. Create a complex type in Java:

   public class CustomType {
       private String myValue;
       CustomType(String value) {
           myValue = value;
       }
   
       String getMyValue() {
           return myValue;
       }
       public void setMyValue(String newValue) {
           myValue = newValue;
       }
   }
   

3. Create a Java class implementing SnippetObjectConverter, which defines how the complex type should be converted against JSONObject:

   public class ExampleObjectConverter implements SnippetObjectConverter {
       @Override
       public JSONObject serialize(Object object) throws JSONException {
           JSONObject result = new JSONObject();
           if (object instanceof CustomType) {
               CustomType input = (CustomType) object;
               result.put("Value", input.getMyValue());
               return result;
           }
           return null;
       }
   
       @Override
       public Object deserialize(JSONObject jsonObject, Type type) throws JSONException {
           if (type == CustomType.class) {
               return new CustomType(jsonObject.getString("Value"));
           }
           return null;
       }
   }
   

4. Write a Java class implementing Snippet and add Rpc methods that takes your complex type as a parameter and another Rpc method that returns the complext type directly.

   package com.my.app;
   ...
   public class ExampleSnippet implements Snippet {
       @Rpc(description = "Pass a complex type as a snippet parameter.")
       public String passComplexTypeToSnippet(CustomType input) {
           Log.i("Old value is: " + input.getMyValue());
           return "The value in CustomType is: " + input.getMyValue();
       }
   
       @Rpc(description = "Returns a complex type from snippet.")
       public CustomType returnComplexTypeFromSnippet(String value) {
           return new CustomType(value);
       }
       @Override
       public void shutdown() {}
   }
   

5. In AndroidManifest.xml, specify the converter class as a meta-data named mobly-object-converter

   <manifest
       xmlns:android="http://schemas.android.com/apk/res/android"
       package="com.my.app">
     <application>
       <meta-data
           android:name="mobly-object-converter"
           android:value="com.my.app.ExampleObjectConverter" />
       ...
   

Running the example code

This folder contains a fully working example of a standalone snippet apk.

1. Compile the example

   ./gradlew examples:ex6_complex_type_conversion:assembleDebug
   

2. Install the apk on your phone

   adb install -r ./examples/ex6_complex_type_conversion/build/outputs/apk/debug/ex6_complex_type_conversion-debug.apk
   

3. Use Mobly's snippet_shell from mobly to trigger the Rpc methods:

   snippet_shell.py com.google.android.mobly.snippet.example6
   
   >>> s.passComplexTypeToSnippet({'Value': 'Hello'})
   'The value in CustomType is: Hello'
   >>> s.returnComplexTypeFromSnippet('Bye')
   {'Value': 'Bye'}