XCall annotations

XCall methods

Usage

Annotate @XCall to a interface or a public method in the score. Note all methods annotated with @XCall has the have the first parameter String from which represents the usual Context.getCaller().

public interface ExampleScore {
    @XCall
    void methodOne(String from, BigInteger amount, byte[] data);

    @XCall
    void methodTwo(String from, String message);

    void handleCallMessage(String _from, byte[] _data);
}

When java compiles, the class ExampleScoreXCall will be generated. Then in your handleCallMessage you can use this class to parse the messages.

import score.Address;
import score.annotation.External;

import java.math.BigInteger;

public class ExampleScoreImpl implements ExampleScore {
    void methodOne(String from, BigInteger amount, byte[] data){
    }

    void methodTwo(String from, String message){
    }

    @External
    void handleCallMessage(String _from, byte[] _data) {
        // Verify caller is XCall contract or other allowed contract.
        ExampleScoreXCall.process(this, _from, _data);
    }
}

XCall messages

When annotating methods with XCall a message factory is also generated for testing and creating messages. Using the above interface (ExampleScore). The class ExampleScoreMessages is generated under the package icon.xcall.lib.messages.ExampleScoreMessages. This class can then be used in both unit and integration tests to generate correct byte messages.

ExampleScoreImplTest class in src/test/java/...

import com.iconloop.score.test.Account;
import com.iconloop.score.test.Score;
import com.iconloop.score.test.ServiceManager;
import com.iconloop.score.test.TestBase;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import icon.xcall.lib.messages.ExampleScoreMessages;

public class ExampleScoreImplTest extends TestBase {
    private static final ServiceManager sm = getServiceManager();
    private static final Account owner = sm.createAccount();
    private static final Account xCallScore = Account.newScoreAccount(1);

    private static Score score;

    @BeforeEach
    public void setup() throws Exception {
        score = sm.deploy(owner, ExampleScoreImpl.class);
    }

    @Test
    public void testMethodTwo() {
        String from = "<BTPAddress>";
        byte[] msg = ExampleScoreMessages.methodTwo("example message");
        score.invoke(xCallScore, "handleCallMessage", from, msg);
    }
}