com.amazon.ask.mvc.view.nashorn.NashornView Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of ask-sdk-mvc Show documentation

The Alexa Skills Kit MVC Framework extends the existing ASK SDK, adding features for mapping requests to methods and rendering responses via view scripts and templates such as Nashorn Javascript and Freemarker. It also integrates with the ASK SDK Interaction Model Mapper framework to create a single environment where both the interaction model and business logic of skills can be managed as code packages.

The newest version!

/*
    Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.

    Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file
    except in compliance with the License. A copy of the License is located at

        http://aws.amazon.com/apache2.0/

    or in the "license" file accompanying this file. This file 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.
 */

package com.amazon.ask.mvc.view.nashorn;

import com.amazon.ask.mvc.view.resolver.ScriptEngineView;
import com.fasterxml.jackson.databind.ObjectMapper;
import jdk.nashorn.api.scripting.ScriptObjectMirror;

import javax.script.ScriptEngine;
import javax.script.ScriptException;

/**
 * Renders a response by passing the model to a JavaScript script. There are three distinct ways to
 * write a view script:
 *
 * 1) A globally scoped function:
 * 
 *     function render(model) {
 *         return {
 *             type: 'PlainText',
 *             text: 'Hello ' + model.name
 *         };
 *     }
 * 
 * 2) A globally scoped object's local function:
 * 
 *     var renderer = {
 *         render: function(model) {
 *             return {
 *                 type: 'PlainText',
 *                 text: 'Hello ' + model.name
 *             };
 *         }
 *     };
 * 
 * 3) Model attributes bound to the global scope and the result is the final expression:
 * 
 *     var result = {
 *         type: 'PlainText',
 *         text: 'Hello ' + name
 *     }
 *
 *     result; // final expression is the result
 * 
 */
public class NashornView extends ScriptEngineView {
    public NashornView(ScriptEngine scriptEngine, String script, String renderObject, String renderFunction, ObjectMapper mapper) throws Exception {
        super(scriptEngine, script, renderObject, renderFunction, mapper);
    }

    /**
     * Support returning a JS object instead of JSON string.
     */
    @Override
    protected String toJson(Object result) throws ScriptException {
        ScriptObjectMirror json = (ScriptObjectMirror) scriptEngine.eval("JSON");
        return (String) json.callMember("stringify", result);
    }
}