Session

Objective

SOAJS provides you the option of using a session with your services. The session gives you the ability to save data in the session and retrieve it from the microservice itself, or any other microservice  with the same session.

This space will show you:

1. How to turn on the session
2. How to add data to the session
3. How to get data from the session
4. Testing the service APIs

Turn on Session

As mentioned before, the session works alongside the microservice, so let's set up a simple microservice.

'use strict';

module.exports = {
   "serviceVersion": 1,
   "serviceName": "hellosession",
   "serviceGroup": "SOAJS Session Example",
   "servicePort": 4120,
   "requestTimeout": 30,
   "requestTimeoutRenewal": 5,
   "extKeyRequired": true,
   "session": true,
   "errors": {
      "400": "please provide a firstName"
   },
   "schema": {
      "/set": {
         "_apiInfo": {
            "l": "set name"
         },
         "firstName": {
            "source": ["body.firstName"],
            "required": true,
            "validation": {
               "type": "string"
            }
         }
      },
      "/get": {
         "_apiInfo": {
            "l": "get name"
         }
      }
   }
};

Before moving on to the index.js file, it will us well to understand how the SOAJS session functions. 

It is not enough to set session to true in the config.js file, the SOAJS session is key driven, meaning we also have to set extKeyRequired to true.

Setting extKeyRequired to true ties out service to a tenant, meaning that the APIs will require a key in order for a request to be successful.

Using the Manage pillar in the Dashboard, create a tenant and use its key in your tests.

'use strict';
var soajs = require('soajs');
var config = require('./config.js');

var service = new soajs.server.service(config);

service.init(function() {
   service.post("/set", function(req, res) {
      req.soajs.session.setSERVICE({"name": req.soajs.inputmaskData.firstName}, function() {
         res.json(req.soajs.buildResponse(null, true));
      });
   });
   service.get("/get", function(req, res) {
      var name = req.soajs.session.getSERVICE().name;
      res.json(req.soajs.buildResponse(null, "Hello " + name));
   });
   
   service.start();
});

Add data to Session

To add a data object to the Session, SOAJS provides a function: req.soajs.session.setSERVICE

The setSERVICE function takes 2 arguments:

• a data object containing the data you want to store in the session
• a callback

Let's have a look at our /set API:

req.soajs.session.setSERVICE({"name": req.soajs.inputmaskData.firstName}, function() {
   res.json(req.soajs.buildResponse(null, true));
});

We are using req.soajs.inputmaskData to retireve the "firstName" we supplied through the body of the post request, and we are creating and object and passing it to setService.

Get data from Session

To get a data object from the Session, SOAJS provides a function: req.soajs.session.getSERVICE

The getSERVICE function takes no arguments.

Let's have a look at out /get API:

var name = req.soajs.session.getSERVICE().name;
res.json(req.soajs.buildResponse(null, "Hello " + name));

We are using the getSERVICE function to retrieve the value of the key from the object that we had passed to the setSERVICE function.

After that, we return the result through the SOAJS response.

Testing the service APIs

Now that everything is set up, we can go ahead and test our service.

Let's turn our service on:

# Go to the directory where you created your config.js and index.js files
cd /opt/soajs/node_modules/session.example


# Run the service
node .

The service is now running and listening for requests. 

Using a terminal window, Postman, Insomnia, etc... we can test our service.