Your First Ottoman App

This is a sample application for getting started with Ottoman using Couchbase Server. The application provides a Rest API and demonstrates ODM capabilities using Ottoman v2, Couchbase Node.js SDK 3, and Express. The application is a flight planner that allows the user to search for and select a flight route (including return flight) based on airports and dates.

Prepare Couchbase Server

To use the API, one would need to have Couchbase Server running locally. Setup Couchbase Server using docker.

Follow instructions to Setup a new cluster and once the database is running, install the required dataset: travel-sample.

JavaScript Prerequisites

Node.js and Yarn should be installed before running this project.

Prepare Our Project Folder

We can bootstrap our application. Create a directory and clone the repository from GitHub.

Development Guide

1. Clone this repo and install dependencies

git clone https://github.com/couchbaselabs/try-ottoman.git
cd try-ottoman
yarn install

2. Set up Environment Variables

   • Copy the .env.example to a new file called .env

   cp .env.example .env
   

   • Set the appropriate variables in the OTTOMAN_CONNECTION_STRING:
     • The format of the connection string is: couchbase://<cluster_ip>:<cluster_port>/<bucket_name>@<username>:<password>
     • The connection string in .env.example will work for a locally hosted Couchbase cluster with username Administrator and password password. Change the string as needed to fit your cluster.
     • This API uses the travel-sample bucket, which you'll need to add to your cluster for proper functionality. Learn more about installing sample buckets here.

3. Run the API example

yarn start

Tutorial Project (Travel-Sample) Goals

• A REST API built with Express and Ottoman V2
• Store hotels, flight, and airport information
• The Couchbase travel-sample data set will be the system of record

Data Model

The flexibility and dynamic nature of a NoSQL Document Database and JSON simplifies building the data model. For the travel-sample application we will use three types of objects, and we'll define those in specific modules in the node application.

• airports
• flightPaths
• hotels

The source code is organized by modules inside the src directory. Each module defines a set of REST endpoints, and the data model of a resource. Data models are defined in files ending with: .model.js using Otoman's { model, Schemea } named exports, and it's corresponding endpoints are defined in the files ending with: .controller.js, using Express JS.

Let's walk through the code starting with the hotels module.

Hotel Model

The first section of the hotel module instantiates module dependencies, which are Ottoman and the database file where the information on the Couchbase instance is stored for this particular example.

const { model, addValidators, Schema } = require('ottoman');    // ← use ottoman
const { GeolocationSchema } = require('../shared/geolocation.schema');

Next, a custom validator function is defined to make sure that a phone number in the standard USA format is created.

addValidators({
  phone: (value) => {
    const regex = /^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$/;
    if (value && !value.match(regex)) {
      throw new Error('Phone number is invalid.');
    }
  },
});

The model for the Hotels object is defined using several of the Ottoman built-in types. For reference, see http://www.ottoman.com. Several indices are defined along with the model. The indices are utilized as methods for each instance of the Hotel Object. Ottoman supports complex data types, embedded references to other models, and customization.

We are going to define a custom type link

const { IOttomanType, ValidationError, registerType } = require('ottoman');

/**
 * Custom type to manage the links
 */
class LinkType extends IOttomanType {
  constructor(name: string) {
    super(name, 'Link');
  }
  
  cast(value) {
    this.validate(value);
      return String(value);
  }
    
  validate(value, strict) {
    if (value && !isLink(String(value))) {
      throw new ValidationError(`Field ${this.name} only allows a Link`);
    }
    return String(value);
  }
}

/**
 * Factory function
 * @param name of field
 */
const linkTypeFactory = (name) => new LinkType(name);

/**
 * Register type on Schema Supported Types
 */
registerType(LinkType.name, linkTypeFactory);

/**
 * Check if value is a valid Link
 * @param value
 */
function isLink(value: string) {
  const regExp = new RegExp(
    /https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)/gi,
  );
  return regExp.test(value);
};

module.exports = {
  LinkType
}

With the link custom type, we continue with the schema definition

const ReviewSchema = new Schema({
  author: String,
  content: String,
  date: Date,
  ratings: {
    Cleanliness: { type: Number, min: 1, max: 5 },
    Overall: { type: Number, min: 1, max: 5 },
    Rooms: { type: Number, min: 1, max: 5 },
    Service: { type: Number, min: 1, max: 5 },
    Value: { type: Number, min: 1, max: 5 },
  },
});

const HotelSchema = new Schema({
  address: { type: String, required: true },
  alias: String,
  checkin: String,
  checkout: String,
  city: { type: String, required: true },
  country: { type: String, required: true },
  description: String,
  directions: [String],
  email: String,
  fax: String,
  free_breakfast: Boolean,
  free_internet: Boolean,
  free_parking: Boolean,
  geo: GeolocationSchema,
  name: { type: String, required: true },
  pets_ok: Boolean,
  phone: { type: String, validator: 'phone' }, // My custom validator
  price: Number,
  public_likes: [String],
  reviews: [ReviewSchema],
  state: String,
  title: String,
  tollfree: String,
  url: LinkType, // My custom type
  vacancy: Boolean,
});

HotelSchema.index.findByName = { by: 'name', type: 'n1ql' };

const HotelModel = model('hotel', HotelSchema);
module.exports = {
  HotelModel
}

In the Hotel model above, there is one explicit index defined. By default, if an index type is not specified Ottoman will select the fastest available index supported within the current Couchbase cluster.

In addition to utilizing built-in secondary index support within Couchbase, Ottoman can also utilize referential documents and maintain the referential integrity for updates and deletes, a feature that allows fast lookups by field.

This type of index in Ottoman is useful for finding a particular object by a unique field such as customer id or email address in the example above. In addition to any explicit index, Ottoman also provides a generic find capability using the query API and N1QL.

Airport Model

The airport module begins much the same way as the hotel module.

const { model, addValidators, Schema } = require('ottoman');  // ← use ottoman
const { GeolocationSchema } = require('../shared/geolocation.schema');

As in the Hotel model, the Airport object is defined with several different data types, embedded references to other models and explicitly defined secondary indexes.

const AirportSchema = new Schema({
 airportname: { type: String, required: true },
 city: { type: String, required: true },
 country: { type: String, required: true },
 faa: String,
 geo: GeolocationSchema,
 icao: String,
 tz: { type: String, required: true },
});

AirportSchema.index.findByName = { by: 'name', type: 'n1ql' };

const AirportModel = model('airport', AirportSchema);
module.exports = {
  AirportModel
}

The index like in the hotel example are.

Application and Routing

Now that the models are defined above, the controller functionality is defined in the server.js file in the root directory and the routes on files *.controller.js in the module directory.

App

The index.js file is the entry point to the application and defines how the application will function. The code within the file is as follows:

const express = require('express');
const ottoman = require('ottoman');
const swaggerUi = require('swagger-ui-express');
const YAML = require('yamljs');
const { HotelRoutes } = require('./src/hotels/hotels.controller');
const { AirportRoutes } = require('./src/airports/airports.controller');
const { FlightRoutes } = require('./src/flights/flights.controller');

const app = express();

app.use(express.json());
app.get('/', (req, res) => {
  res.send('index');
});
app.use('/airports', jwtMiddleware, AirportRoutes);
app.use('/hotels', jwtMiddleware, HotelRoutes);
app.use('/flightPaths', jwtMiddleware, RouteRoutes);

app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(YAML.load('./api/swagger.yaml')));

// Handle not found and catch exception layer
app.use((err, req, res, next) => {
  return res.status(500).json({ error: err.toString() });
});

ottoman.start()
  .then(() => {
    console.log('All the indexes were registered');
    const port = 4500;
    app.listen(port, () => {
      console.log(`API started at http://localhost:${port}`);
      console.log(`API docs at http://localhost:${port}/api-docs/`);
    });
  })
  .catch((e) => console.log(e));
// ← API started at http://localhost:4500

Swagger Documentation

After running yarn start, Once you have the example running, you can find all definitions in Swagger:

http://localhost:4500/api-docs/