use backbone models from nashorn

winterbe · winterbe · commit ebe8ada20d20 · 2014-04-01T20:03:34.000+02:00
diff --git a/res/nashorn6.js b/res/nashorn6.js
@@ -0,0 +1,47 @@
+load('http://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js');
+load('http://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.1.2/backbone-min.js');
+
+
+// simple backbone model:
+// valueOfGoods will automatically be calculated when stock or price changes
+var Product = Backbone.Model.extend({
+    defaults: {
+        stock: 0,
+        price: 0.0,
+        name:'',
+        valueOfGoods: 0.0
+    },
+
+    initialize: function() {
+        this.on('change:stock change:price', function() {
+            var stock = this.get('stock');
+            var price = this.get('price');
+            var valueOfGoods = this.getValueOfGoods(stock, price);
+            this.set('valueOfGoods', valueOfGoods);
+        });
+    },
+
+    getValueOfGoods: function(stock, price) {
+        return stock * price;
+    }
+});
+
+var product = new Product();
+product.set('name', 'Pencil');
+product.set('stock', 1000);
+product.set('price', 3.99);
+
+
+// pass backbone model to java method
+var Nashorn6 = Java.type('com.winterbe.java8.Nashorn6');
+Nashorn6.getProduct(product.attributes);
+
+
+// bind java object to backbone model and pass result back to java
+var calculate = function(javaProduct) {
+    var model = new Product();
+    model.set('name', javaProduct.name);
+    model.set('price', javaProduct.price);
+    model.set('stock', javaProduct.stock);
+    return model.attributes;
+};
diff --git a/src/com/winterbe/java8/Nashorn6.java b/src/com/winterbe/java8/Nashorn6.java
@@ -0,0 +1,36 @@
+package com.winterbe.java8;
+
+import jdk.nashorn.api.scripting.ScriptObjectMirror;
+
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+
+/**
+ * Using Backbone Models from Nashorn.
+ *
+ * @author Benjamin Winterberg
+ */
+public class Nashorn6 {
+
+    public static void main(String[] args) throws Exception {
+        ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
+        engine.eval("load('res/nashorn6.js')");
+
+        Invocable invocable = (Invocable) engine;
+
+        Product product = new Product();
+        product.setName("Rubber");
+        product.setPrice(1.99);
+        product.setStock(1337);
+
+        ScriptObjectMirror result = (ScriptObjectMirror)
+                invocable.invokeFunction("calculate", product);
+        System.out.println(result.get("name") + ": " + result.get("valueOfGoods"));
+    }
+
+    public static void getProduct(ScriptObjectMirror result) {
+        System.out.println(result.get("name") + ": " + result.get("valueOfGoods"));
+    }
+
+}
diff --git a/src/com/winterbe/java8/Product.java b/src/com/winterbe/java8/Product.java
@@ -7,6 +7,15 @@ public class Product {
     private String name;
     private double price;
     private int stock;
+    private double valueOfGoods;
+
+    public double getValueOfGoods() {
+        return valueOfGoods;
+    }
+
+    public void setValueOfGoods(double valueOfGoods) {
+        this.valueOfGoods = valueOfGoods;
+    }
 
     public String getName() {
         return name;
