com.vaadin.server.JavaScriptCallbackHelper Maven / Gradle / Ivy
/*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.server;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import com.vaadin.shared.JavaScriptConnectorState;
import com.vaadin.ui.AbstractJavaScriptComponent;
import com.vaadin.ui.JavaScript.JavaScriptCallbackRpc;
import com.vaadin.ui.JavaScriptFunction;
import com.vaadin.util.ReflectTools;
import elemental.json.JsonArray;
import elemental.json.JsonException;
/**
* Internal helper class used to implement functionality common to
* {@link AbstractJavaScriptComponent} and {@link AbstractJavaScriptExtension}.
* Corresponding support in client-side code is in
* {@code com.vaadin.client.JavaScriptConnectorHelper}.
*
* You should most likely no use this class directly.
*
* @author Vaadin Ltd
* @since 7.0.0
*/
public class JavaScriptCallbackHelper implements Serializable {
private static final Method CALL_METHOD = ReflectTools.findMethod(
JavaScriptCallbackRpc.class, "call", String.class, JsonArray.class);
private final AbstractClientConnector connector;
private final Map callbacks = new HashMap<>();
private JavaScriptCallbackRpc javascriptCallbackRpc;
public JavaScriptCallbackHelper(AbstractClientConnector connector) {
this.connector = connector;
}
public void registerCallback(String functionName,
JavaScriptFunction javaScriptCallback) {
callbacks.put(functionName, javaScriptCallback);
JavaScriptConnectorState state = getConnectorState();
state.getCallbackNames().add(functionName);
ensureRpc();
}
private JavaScriptConnectorState getConnectorState() {
JavaScriptConnectorState state = (JavaScriptConnectorState) connector
.getState();
return state;
}
private void ensureRpc() {
if (javascriptCallbackRpc == null) {
// Note that javascriptCallbackRpc is not a lambda to make sure it
// can be serialized properly
javascriptCallbackRpc = new JavaScriptCallbackRpc() {
@Override
public void call(String name, JsonArray arguments) {
JavaScriptFunction callback = callbacks.get(name);
try {
callback.call(arguments);
} catch (JsonException e) {
throw new IllegalArgumentException(e);
}
}
};
connector.registerRpc(javascriptCallbackRpc);
}
}
public void invokeCallback(String name, Object... arguments) {
if (callbacks.containsKey(name)) {
throw new IllegalStateException("Can't call callback " + name
+ " on the client because a callback with the same name is registered on the server.");
}
JsonArray args = (JsonArray) JsonCodec
.encode(arguments, null, Object[].class, null)
.getEncodedValue();
connector.addMethodInvocationToQueue(
JavaScriptCallbackRpc.class.getName(), CALL_METHOD,
new Object[] { name, args });
}
public void registerRpc(Class rpcInterfaceType) {
if (rpcInterfaceType == JavaScriptCallbackRpc.class) {
// Ignore
return;
}
Map> rpcInterfaces = getConnectorState()
.getRpcInterfaces();
String interfaceName = rpcInterfaceType.getName();
if (!rpcInterfaces.containsKey(interfaceName)) {
Set methodNames = new HashSet<>();
for (Method method : rpcInterfaceType.getMethods()) {
methodNames.add(method.getName());
}
rpcInterfaces.put(interfaceName, methodNames);
}
}
}