Android™

Call a JavaScript Function Returning an Object

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Demonstrates how to call a JavaScript function that returns an object. Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    // This is the JavaScript function we'll call:

    // function getSettings() {
    //     return {
    //         theme: "dark",
    //         notifications: true,
    //         version: 1.0
    //     };
    // }

    CkStringBuilder sbScript = new CkStringBuilder();
    sbScript.Append("function getSettings() {");
    sbScript.Append("    return {");
    sbScript.Append("        theme: \"dark\",");
    sbScript.Append("        notifications: true,");
    sbScript.Append("        version: 1.0");
    sbScript.Append("    };");
    sbScript.Append("}");

    CkJs js = new CkJs();

    CkJsonObject result = new CkJsonObject();
    result.put_EmitCompact(false);

    // Call Eval to add the function to the context's global object
    success = js.Eval(sbScript,result);
    if (success == false) {
        // Examine the result for an exception.
        Log.i(TAG, result.emit());

        // Also examine the LastErrorText.
        Log.i(TAG, js.lastErrorText());
        return;
        }

    // ------------------------------------------------------------------------------
    // Call the function getSettings()

    CkJsonObject funcCall = new CkJsonObject();

    // Create JSON specifying the function name and arguments
    // The function has no arguments, so we only specify the name.

    // {
    //   "name": "getSettings",
    // }

    funcCall.UpdateString("name","getSettings");

    success = js.CallFunction(funcCall,result);
    if (success == false) {
        // Examine the result for an exception.
        Log.i(TAG, result.emit());

        // Also examine the LastErrorText.
        Log.i(TAG, js.lastErrorText());
        return;
        }

    Log.i(TAG, result.emit());

    // Output:
    // {
    //   "type": "object",
    //   "value": {
    //     "theme": "dark",
    //     "notifications": true,
    //     "version": 1
    //   }
    // }

    // Examine the object's members
    Log.i(TAG, "theme: " + result.stringOf("value.theme"));
    Log.i(TAG, "notifications: " + String.valueOf(result.BoolOf("value.notifications")));
    Log.i(TAG, "version: " + String.valueOf(result.IntOf("value.version")));

    // Output:
    // theme: dark
    // notifications: True
    // version: 1

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}