project-structure.md

Project Structure

In this section, you will learn more about the project structure of a Jovo Voice App.

• Overview
• Project Files
  • project.js - Project Configuration
  • models - Language Model
  • platforms - Platform Files
• Source Files
  • app.js - App Logic
  • config.js - App Config
  • index.js - Host Configuration

Overview

A Jovo project is divided into two main building blocks:

• Project Files: Overall project related files, e.g. language models and platform project information
• Source Files: The actual code of your app. Can be found in the src folder

Project Files

These files are in the root folder and include anything that is needed to publish a project to voice platforms like Amazon Alexa and Google Assistant.

Project files include:

• project.js - Project Configuration
• models - Language Model
• platforms - Platform Files

project.js - Project Configuration

The project.js file stores all the necessary information for your Jovo project, for example which voice platforms are built for.

Here is the project.js file of the Jovo Sample App:

// ------------------------------------------------------------------
// JOVO PROJECT CONFIGURATION
// ------------------------------------------------------------------

module.exports = {
   alexaSkill: {
      nlu: 'alexa',
   },
   googleAction: {
      nlu: 'dialogflow',
   },
   endpoint: '${JOVO_WEBHOOK_URL}',
};

Learn more about the project.js file here.

models - Language Model

The models folder contains the Jovo Language Model, which can be used to create and update platform specific language models using the Jovo CLI.

The idea is to maintain a single language model locally instead of having to go to the platform developer consoles independently.

In the models folder, every language gets a file. For example, here's how a file en-US.json could look like:

{  
    "invocation": "my test app",
    "intents":[  
        {  
            "name":"HelloWorldIntent",
            "phrases":[  
                "hello",
                "say hello",
                "say hello world"
            ]
        },
        {  
            "name":"MyNameIsIntent",
            "phrases":[  
                "{name}",
                "my name is {name}",
                "i am {name}",
                "you can call me {name}"
            ],
            "inputs":[  
                {  
                    "name":"name",
                    "type":{  
                        "alexa":"AMAZON.US_FIRST_NAME",
                        "dialogflow":"@sys.given-name"
                    }
                }
            ]
        }
    ]
}

Learn more about the Jovo Language Model here.

platforms - Platform Files

The platforms folder is created by the Jovo CLI. Each platform (like Amazon Alexa and Google Assistant) gets its own folder with project files and language models. These files are then used to deploy the projects to the voice platforms.

Learn more about the Platforms folder here.

Source Files

In the src folder, you can find the actual code of your Jovo app. This part is later deployed to hosting providers like AWS Lambda.

• app.js - App Logic
• config.js - App Config
• index.js - Host Configuration

app.js - App Logic

The app.js file is used for the logic of your voice application, which contains handlers, intents, and the configuration of your voice app:

'use strict';

// ------------------------------------------------------------------
// APP INITIALIZATION
// ------------------------------------------------------------------

const { App } = require('jovo-framework');
const { Alexa } = require('jovo-platform-alexa');
const { GoogleAssistant } = require('jovo-platform-googleassistant');
const { JovoDebugger } = require('jovo-plugin-debugger');
const { FileDb } = require('jovo-db-filedb');

const app = new App();

app.use(
    new Alexa(),
    new GoogleAssistant(),
    new JovoDebugger(),
    new FileDb()
);


// ------------------------------------------------------------------
// APP LOGIC
// ------------------------------------------------------------------

app.setHandler({
    LAUNCH() {
        return this.toIntent('HelloWorldIntent');
    },

    HelloWorldIntent() {
        this.ask('Hello World! What\'s your name?', 'Please tell me your name.');
    },

    MyNameIsIntent() {
        this.tell('Hey ' + this.$inputs.name.value + ', nice to meet you!');
    },
});

module.exports.app = app;

You can find everything related to the app.js here.

config.js - App Config

The config.js file stores all the logic-related configuration:

// ------------------------------------------------------------------
// APP CONFIGURATION
// ------------------------------------------------------------------

module.exports = {
   logging: true,

   intentMap: {
      'AMAZON.StopIntent': 'END',
   },

   db: {
        FileDb: {
            pathToFile: '../db/db.json',
        }
    },
};

You can find everything related to the config.js here.

index.js - Host Configuration

Everything related to running and hosting your voice application, either in Lambda or using a webhook (recommended for local prototyping), is dealt with in index.js file:

'use strict';

const { Webhook, ExpressJS, Lambda } = require('jovo-framework');
const { app } = require ('./app.js');

// ------------------------------------------------------------------
// HOST CONFIGURATION
// ------------------------------------------------------------------

// ExpressJS (Jovo Webhook)
if (process.argv.indexOf('--webhook') > -1) {
    const port = process.env.PORT || 3000;

    Webhook.listen(port, () => {
        console.info(`Local server listening on port ${port}.`);
    });

    Webhook.post('/webhook', async (req, res) => {
        await app.handle(new ExpressJS(req, res));
    });
}

// AWS Lambda
exports.handler = async (event, context, callback) => {
    await app.handle(new Lambda(event, context, callback));
};

Learn everything related to host configuration and the index.js file here.