Java

Call a JavaScript Function Returning an Object

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

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    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.
        System.out.println(result.emit());

        // Also examine the LastErrorText.
        System.out.println(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.
        System.out.println(result.emit());

        // Also examine the LastErrorText.
        System.out.println(js.lastErrorText());
        return;
        }

    System.out.println(result.emit());

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

    // Examine the object's members
    System.out.println("theme: " + result.stringOf("value.theme"));
    System.out.println("notifications: " + result.BoolOf("value.notifications"));
    System.out.println("version: " + result.IntOf("value.version"));

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