feat: add executeJs helper

src/main/java/com/flowingcode/vaadin/jsonmigration/ElementalPendingJavaScriptResult.java

@@ -0,0 +1,90 @@
+/*-
+ * #%L
+ * Json Migration Helper
+ * %%
+ * Copyright (C) 2025 Flowing Code
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+package com.flowingcode.vaadin.jsonmigration;
+/*
+ * Copyright 2000-2025 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+import com.vaadin.flow.component.page.PendingJavaScriptResult;
+import com.vaadin.flow.function.SerializableConsumer;
+import elemental.json.JsonValue;
+import java.io.Serializable;
+
+/**
+ * A pending result from a JavaScript snippet sent to the browser for evaluation. This interface
+ * utilizes Elemental JSON in order to abstract away breaking changes introduced in Vaadin version
+ * 25.
+ *
+ * @see PendingJavaScriptResult
+ * @author Vaadin Ltd
+ */
+public interface ElementalPendingJavaScriptResult extends Serializable {
+
+    /**
+     * Adds an untyped handler that will be run for a successful execution and a
+     * handler that will be run for a failed execution. One of the handlers will
+     * be invoked asynchronously when the result of the execution is sent back
+     * to the server. It is not possible to synchronously wait for the result of
+     * the execution while holding the session lock since the request handling
+     * thread that makes the result available will also need to lock the
+     * session.
+     * <p>
+     * Handlers can only be added before the execution has been sent to the
+     * browser.
+     *
+     * @param resultHandler
+     *            a handler for the JSON representation of the value from a
+     *            successful execution, not <code>null</code>
+     * @param errorHandler
+     *            a handler for an error message in case the execution failed,
+     *            or <code>null</code> to ignore errors
+     */
+    void then(SerializableConsumer<JsonValue> resultHandler,
+            SerializableConsumer<String> errorHandler);
+
+    /**
+     * Adds an untyped handler that will be run for a successful execution. The
+     * handler will be invoked asynchronously if the execution was successful.
+     * In case of a failure, no handler will be run.
+     * <p>
+     * A handler can only be added before the execution has been sent to the
+     * browser.
+     *
+     * @param resultHandler
+     *            a handler for the JSON representation of the return value from
+     *            a successful execution, not <code>null</code>
+     */
+    default void then(SerializableConsumer<JsonValue> resultHandler) {
+        then(resultHandler, null);
+    }
+
+}

src/main/java/com/flowingcode/vaadin/jsonmigration/JsonMigration.java

@@ -19,11 +19,13 @@
  */
 package com.flowingcode.vaadin.jsonmigration;
 
+import com.vaadin.flow.component.page.PendingJavaScriptResult;
 import com.vaadin.flow.dom.DomEvent;
 import com.vaadin.flow.dom.Element;
 import com.vaadin.flow.server.Version;
 import elemental.json.JsonObject;
 import elemental.json.JsonValue;
+import java.io.Serializable;
 import java.lang.reflect.Method;
 import lombok.SneakyThrows;
 
@@ -114,6 +116,22 @@ public static void setPropertyJson(Element element, String name, JsonValue json)
     invoke(Element_setPropertyJson, element, name, json);
   }
 
+  /**
+   * Asynchronously runs the given JavaScript expression in the browser in the context of this
+   * element.
+   *
+   * @param element the {@code Element} on which to run the JavaScript expression
+   * @param expression the JavaScript expression to invoke
+   * @param parameters parameters to pass to the expression
+   * @return a pending result that can be used to get a value returned from the expression
+   * @see Element#executeJs(String, Serializable...)
+   */
+  public static ElementalPendingJavaScriptResult executeJs(Element element, String expression,
+      Serializable... parameters) {
+    PendingJavaScriptResult result = element.executeJs(expression, parameters);
+    return helper.convertPendingJavaScriptResult(result);
+  }
+
   /**
    * Gets additional data related to the event.
    *

src/main/java/com/flowingcode/vaadin/jsonmigration/JsonMigrationHelper.java

@@ -19,6 +19,7 @@
  */
 package com.flowingcode.vaadin.jsonmigration;
 
+import com.vaadin.flow.component.page.PendingJavaScriptResult;
 import elemental.json.JsonValue;
 
 import java.lang.reflect.Method;
@@ -29,5 +30,7 @@ interface JsonMigrationHelper {
   JsonValue convertToJsonValue(Object object);
 
   Object invoke(Method method, Object instance, Object... args);
-
+
+  ElementalPendingJavaScriptResult convertPendingJavaScriptResult(PendingJavaScriptResult result);
+
 }

src/main/java/com/flowingcode/vaadin/jsonmigration/JsonMigrationHelper25.java

@@ -21,10 +21,13 @@
 
 import java.lang.reflect.Method;
 import java.util.Arrays;
+import com.vaadin.flow.component.page.PendingJavaScriptResult;
+import com.vaadin.flow.function.SerializableConsumer;
 import elemental.json.Json;
 import elemental.json.JsonArray;
 import elemental.json.JsonObject;
 import elemental.json.JsonValue;
+import lombok.AllArgsConstructor;
 import lombok.NoArgsConstructor;
 import lombok.SneakyThrows;
 import tools.jackson.databind.JsonNode;
@@ -135,4 +138,31 @@ private static BaseJsonNode convertToJsonNode(JsonValue jsonValue) {
     }
   }
 
+
+  @Override
+  public ElementalPendingJavaScriptResult convertPendingJavaScriptResult(
+      PendingJavaScriptResult result) {
+    return new PendingJavaScriptResultImpl(result);
+  }
+
+  @SuppressWarnings("serial")
+  @AllArgsConstructor
+  private static final class PendingJavaScriptResultImpl
+      implements ElementalPendingJavaScriptResult {
+    private final PendingJavaScriptResult delegate;
+
+    @SuppressWarnings("rawtypes")
+    private static SerializableConsumer wrap(SerializableConsumer<JsonValue> resultHandler) {
+      return (SerializableConsumer<JsonNode>) node -> resultHandler.accept(convertToJsonValue(node));
+    };
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public void then(SerializableConsumer<JsonValue> resultHandler,
+        SerializableConsumer<String> errorHandler) {
+      delegate.then(wrap(resultHandler), errorHandler);
+    }
+
+  }
+
 }

src/main/java/com/flowingcode/vaadin/jsonmigration/LegacyJsonMigrationHelper.java

@@ -19,10 +19,13 @@
  */
 package com.flowingcode.vaadin.jsonmigration;
 
+import com.vaadin.flow.component.page.PendingJavaScriptResult;
 import java.lang.reflect.Method;
 import elemental.json.JsonValue;
+import lombok.AllArgsConstructor;
 import lombok.NoArgsConstructor;
 import lombok.SneakyThrows;
+import lombok.experimental.Delegate;
 
 @NoArgsConstructor
 class LegacyJsonMigrationHelper implements JsonMigrationHelper {
@@ -43,4 +46,18 @@ public Object invoke(Method method, Object instance, Object... args) {
     return method.invoke(instance, args);
   }
 
+  @Override
+  public ElementalPendingJavaScriptResult convertPendingJavaScriptResult(
+      PendingJavaScriptResult result) {
+    return new PendingJavaScriptResultImpl(result);
+  }
+
+  @SuppressWarnings("serial")
+  @AllArgsConstructor
+  private static final class PendingJavaScriptResultImpl
+      implements ElementalPendingJavaScriptResult, PendingJavaScriptResult {
+    @Delegate
+    private final PendingJavaScriptResult delegate;
+  }
+
 }