Communicate between Child and Parent Components in React JS of SUSI Web Chat

When we were developing SUSI AI web chat  some components became huge. So the team wanted to break some components into parts. Since the Login dialog-box is used in several  places we decided to make a separate component for Login Dialog-box. In this post I am discussing how we implemented the feature as a separate component and how we have changed the state of the parent component of the child component.

Login Dialog-box contains all the things of the login dialog-box component.

Child-component (Login Dialog-box component) is here:

This method executes the ‘switchDialog’ function of the parent component.

export default class LoginDialog extends React.Component {

   handleClose = () => {

   render() {
       this.state = { open: }
       const actions = <RaisedButton
               UserPreferencesStore.getTheme() === 'light' ? '#607D8B' : '#19314B'}

       return (
               contentStyle={{ width: '35%', minWidth: '300px' }}
               <Login {...this.props} />


In this part we validate property types that has passed from the parent component.

LoginDialog.propTypes = {
   open: PropTypes.bool,
   switchDialog: PropTypes.func

In render() method I have returned the element.
To open and close dialog we have to communicate with parent component. We can send an instruction as an attribute of the element and we can refer it inside the element as “props”. This is how I have sent an instruction to the child element.
‘handleOpen’ function opens the dialog when user hit on the login button.

   handleOpen = () => {
       this.setState({ open: true });

‘switchDialog’ function is using for change the state of parent component from child Component (Login Dialog-box component).


   render() {

       const styles = {
           'margin': '60px auto',
           'width': '100%',
           'padding': '20px',
           'textAlign': 'center'

       return (
           <div className="signUpForm">
               <Paper zDepth={1} style={styles}>
                   <h1>Sign Up with SUSI</h1>
                   <form onSubmit={this.handleSubmit}>
                           <h4>If you have an Account Please Login</h4>
                                   ? '#607D8B' : '#19314B'}
                               labelColor="#fff" />

               <LoginDialog {...this.props} open={} switchDialog={this.switchDialog} />

To open and close the dialog-box we have to send the state of the parent component to child component. To close the dialog-box we have to update the parent component’s state from child component.

To change the parent component’s state we have used this in element.


To send the state to the child component we used this.


To send other properties to the element we used this.


After closing the dialog-box it calls this method and it updates the state of the parent component.

handleClose = () => {

This is how we can communicate between child and parent components using react.


Component Communication:
Material UI Dialogs:

React Routes to Deploy 404 page on gh-pages and surge

Web applications need 404 page to handle broken urls. If we can have a productive 404 page we can keep users with our application. This is how we made 404 page to SUSI.AI web chat application.
React routes ?
We use react routes to navigate throughout the application.we have to define which page to go from each and every route. If user is trying to go to broken Link application should show 404 page.
In the SUSI Web Chat application we have setuped routes in index.js file which is on the root of the application.

<Router history={hashHistory}>
                <Route exact path="/" component={ChatApp} />
                <Route exact path="/signup" component={SignUp} />
                <Route exact path="/logout" component={Logout} />
                <Route exact path="/forgotpwd" component={ForgotPassword} />
                <Route exact path="*" component={NotFound} />


“<Route exact path=”*” component={NotFound} />”  This line defines the 404 page route . this should be defined after all other routes. Because application should first search for defined routes.If the requested route is not defined, Application should show the 404 route.
To use these JSX elements we have to import this dependency on top of the index.js

import {
    BrowserRouter as Router,
} from 'react-router-dom';


After you define like this It will work correctly on your localhost after you deployed it on gh-pages or surge it will not be work there as we wish.
When we try to access URL directly or when we try to access wrong URL it will redirect to default github 404 page.

After we built our application we get static index.html file and another set of files.when we try to access it will load index.html file. If we access another url it will automatically loads default github pages 404 page.
So we can do a little hack for use direct URLs like this .
We can add same copy of index.html file as 404.html then user tries to go to different URL instead of It loads our 404.html file since it contains all other routes it redirects to the correct route.if there is no matching route it shows our 404 page instead of default github pages 404 page.
Since all our deployment tasks are handle by we have to add this actions into file like this.

rm -rf node_modules/	 
mv ../build/* .
cp index.html 404.html   <--- this part


Then it will create 404.html file with the content of index.html file after each and every commit.
If you need to do the same thing on (we use surge for show previews of every PR ) we have to add a copy of index.html file as 200.html .
You can do this after you run the

npm run deploy


Just before giving the deployment URL you need to create a copy of index.html file on build folder and it should be renamed as 200.html and it will work as we wish. This is all for today.


  • Read More – Adding a 200 page for client-side routing :

Test SUSI Web App with Facebook Jest

Jest is used by Facebook to test all Javascript codes specially React code snippets. If you need to setup jest on your react application you can follow up these simple steps. But if your React application is made with “create-react-app”, you do not need to setup jest manually. Because it comes with Jest. You can run test using “react-scripts” node module.

Since SUSI chat is made with “create-react-app” we do not need to install and run Jest directly. We executed our test cases using “npm test” it executes “react-scripts test” command. It executes all “.js” files under “__tests__” folders. And all other files with “.spec.js” and “.test.js” suffixes.

React apps that are made from “create-react-app” come with sample test case (smoke test) and that checks whether whole application is built correctly or not. If it passes the smoke test then it starts to run further test cases.

import React from 'react';
import ReactDOM from 'react-dom';
import ChatApp from '../../components/ChatApp.react';
it('renders without crashing', () => {
 const div = document.createElement('div');
 ReactDOM.render( < ChatApp / > , div);

This checks all components which are inside of the “<ChatApp />” component and it check whether all these components integrate correctly or not.

If we need to check only one component in isolated environment. We can use shallow rendering API. we have used shallow rendering API to check each and every component in isolated environment.

We have to install enzyme and test renderer before use it.

npm install --save-dev enzyme react-test-renderer

import React from 'react';
import MessageSection from '../../components/MessageSection.react';
import { shallow } from 'enzyme';
it('render MessageListItem without crashing',()=>{
  shallow(<MessageSection />);

This test case tests only the “MessageListItem”, not its child components.

After executing “npm test” you will get the passed and failed number of test cases.

If you need to see the coverage you can see it without installing additional dependencies.

You just need to run this.

npm test -- --coverage

It will show the output like this.

This view shows how many lines, functions, statements, branches your program has and this shows how much of those covered from the test cases you have.

If we are going to write new test cases for susi chat, we have to make separate file in “__tests__” folder and name it with corresponding file name that we are going to test.

it('your test case description',()=>{
 //test what you need 

Normally test cases looks like test cases you can use “test” instead of “it” .after test case description, there is a fat arrow function. In side this fat arrow function you can add what you need to test

In below example I have compared returned value of the function with static value.

function funcName(){
 return 1;

it('your test case description',()=>{

You have to add your function/variable that need to be tested into “expect()” and value you expect from that function or variable into “toBe()”.  Instead of “toBe()” you can use different functions according to your need.

If you have a long list of test cases you can group them ( using describe()).

describe('my beverage', () => {
  test('is delicious', () => {

  test('is not sour', () => {

This post covers only few things of testing . You can learn more about jest testing from official documentation here.

How to add the Google Books API to SUSI AI

SUSI.AI is a Open Source personal assistant. You can also add new skills to SUSI easily. In this blog post I’m going to add Google’s Books API to SUSI as a skill. A complete tutorial on SUSI.AI skills is n the repository. Check out Tutorial Level 11: Call an external API here and you will understand how can we integrate an external API with SUSI AI.

To start adding book skills to SUSI.AI , first go to this URL  > give a name in the text field and press OK.


Copy and paste above code to the newly opened etherpad.

Go to this url to test new skill.

Type “dream blogpost” on chat and press enter. Now we can use the skills we  add to the etherpad.

To understand  Google’s book API use this url.Your request url should be like this:



you should replace APIKey with your API key.

To get started you first need to get an API key.

Go to this url > click GET A KEY button which is in right top > and select “Create a new project”

Add name to a project and click “CREATE AND ENABLE API” button

Copy your API key and replace the API Key part of request URL.

Paste request url on your browser address bar and replace BOOKNAME part with “flower” and go to the URL. It will give this JSON.

We need to get the full name of books which is in items array to that we have to go through this hierarchy
items array >first item>volumeInfo >title
Go to the etherpad we made before and paste the following code.

is there any book called * ?
!console:did you mean "$title$" ? Here is a link to read more: $infoLink$

first line of the code “is there any book called *?” is the question user ask. *  is the variant part  of question. that part can be used in the code by $1$ , if there more variants we can add multiple asterisk marks and refer by using corresponding number Ex: $1$,$2$,$3$
  • In this code  “path” : “$.items[0].volumeInfo”
  • $  represents full JSON result.
  • items[0] for get first element
  • .volumeInfo is to refer  volumeInfo object
!console:did you mean “$title$” ?  Here is a link to read more: $infoLink$
this line produce the output.
  • $title$ this one is for refer the “title” part of data that comes from “path”
  • $infoLink$ this one gives link to more details

Now go to the chat UI and type again “dream blogpost”. And after it shows “dreaming enabled” type in”is there any book called world war?”. It will result in the following.

This  is a simple way to add any service to SUSI as a skill.