Java
This is another preview language feature defined in java 13. Java 13 extends the previous Java 12 Switch expressions by adding a new yield keyword to return a value from switch expression. So break syntax is no longer compiled in Java 13, it uses yield.
As traditional switch statement, there are many break statements make it unnecessarily verbose and hard to debug errors.
Read more “Java 13 Switch Expressions”
Docker
Nginx Load Balancer with docker has become a fine recipe for managing services in closed systems. Although services like Kubernetes provide container orchestration, sometimes architecturally it could be an overkill. In this example, I will be showing how to use docker services using Nginx load balancer.
Read more “Nginx Load Balancer with docker for nodejs services”
JavaScript
Here we are discussing creating react app using npx create-react-app. npx comes with npm 5.2 and higher.
Prerequisite: You need to install Node >= 8.10 on your machine.
npx create-react-app my-app
create-react-app set up the main structure of the application.
Important: If you previously installed create-react-app using npm, uninstall before using npx. Because npx always refer the latest version of libraries.
JavaScript
npx comes bundled with npm version 5.2+.
If you want to run a package using npm, you must specify that package in your package.json file and install a package locally on a project:
npm install package-name
npx is a npm package runner.
JavaScript
This article will guide you on how to create a simple tab component using the react-tabs library.
Install react-tabs using
yarn add react-tabs why yarn ?
JavaScript
Let’s assume we are creating “helloWorld.jsx” like below, you can see there is a compilation error display as “’React’ must be in scope when using JSX react/react-in-jsx-scope.”
const element = <h1>Hello World!</h1> export default element;
This happens due to “React” import necessary in JSX file.The React library must also always be in scope from JSX code. To overcome this error “import React from “react”;” must be added into the file as follows.
Read more “The Common Errors that beginner React Developers Make”
Java
A preview feature or VM feature is a new feature of the Java SE Platform.
This article shows you how to use –enable-preview to enable the preview features in Java 13 with maven.
To use preview features in your programs, you must explicitly enable them in the compiler and the runtime system. Because this feature disabled by default.If not, you’ll receive an error message that states that your code is using a preview feature.
Read more “Enable the Preview Feature in Java 13 with Maven”
AWS
Kubernetes has multiple services to facilitate the pod orchestration within the cluster. What we are discussing here is on how to use the AWS Ingress ALB with EKS without using the traditional Load Balancer Service
FCM
If you are new to firebase and FCM this article will be useful to setup FCM Push Notification with React Native application. We will be using react-native-firebase(doc: https://rnfirebase.io/docs/v5.x.x/getting-started) module to retrieve token for the push notifications.
First, create the Firebase account and download the google-services.json file from the console.
Read more “How to setup FCM Push Notification with React Native App” 
Apollo Client
Query definition in GraphQL is will be something you know now but not mastered. If you were going through the pages to troubleshoot frequent errors with Apollo Client which makes no sense, this post might help. First, the reason to create this post is,
And most importantly if I get into a trouble again, I can refer this 😉 Read more “Query definition in GraphQL and frequent errors with Apollo Client”
OCaml
Ocaml has predefined data structures of tuples, arrays, and lists. There are also mechanisms for defining your own data structures, such as records and variants. In this article, we will discuss about list and tuple.
List can be define as [ element 1 ; element 2 ; element 3; … ].
Read more “OCaml Data Structures”
OCaml
OCaml is a functional language, the main implementation of the Caml programming language created in 1996. OCaml uses to build prototypes of production systems. Facebook, Docker, Bloomberg like well-known companies are now using OCaml to quickly adapt to changing market conditions and go from prototypes to production systems with less effort.
OCaml
Facebook developed Flow, Hack, Infer, Pfff, and Reason using OCaml. And 50 % of the web version of Facebook Messenger has converted to Reason which lets you write simple, fast and quality type safe code while leveraging both the JavaScript & OCaml.
Due to the functional behaviour of OCaml, it helps to quickly adapt changing market conditions and go from prototypes to production systems with less effort.
Read more “Why did Facebook pick OCaml?”
AppSync
Howdy! In this tutorial going to create an AppSync GraphQL Web App with AWS Amplify and IAM Authentication using Cognito User Pools. The reason behind this is, if you are creating an web app quickly, the AWS AppSync, Mobile Hub, DynamoDB will come with all the equipments that you need to scale it. So this is such an attempt but um not using the aws amplify cli to create since I would like to know what my configurations looks like when it comes to web. The App will be a react app to quickly show how its done.
Read more “AppSync GraphQL Web App with AWS Amplify and IAM Authentication”
AppSync
If you are using AppSync GraphQL you must be familiar with the queries with filters. In fact, when you are creating a new type structure, AppSync provides default filters to scan an object in your data source. But how can you query records for a list of keys in GraphQL? Unfortunately, it is not defined in the default filters.
My basic requirement is like this
Read more “Query records for a list of keys in GraphQL AppSync AWS using VTL”
AppSync
Recently, I had to create a AWS Lambda trigger for the AWS DynamoDB table events. The tricky part on this thing was to mutate AWS GraphQL using AWS Lambda with this DynamoDB event. The reason was I wanted all the clients which were subscribed to GraphQL to get this event with modified data.
AppSync
Recently I came up with a react native app which needs to integrate AWS GraphQL. Its actually provided with AWS App Sync and a very convenient way if you want a quick pub-sub. The problem was I had to do mutations as a background asynchronous process and wanted to update the app state from that. When I went through the documents I found the AWSAppSyncClient which is an Apollo Client. Although it was promising the react native examples were more focusing towards react or react-native Components which was really making a mess. Read more “Use AWS GraphQL for React Native Message App”
JavaScript
Recently I got the opportunity to use DatePicker of antd library https://ant.design/components/date-picker/ for a react.js project. It was really cool to use that until I found it was using the whole antd library to import this single antd components. It wasn’t right and there was a solution introduced by the antd team. I just blogged it for anyone who will find it interesting. Read more “How to use antd components without the whole library”
Express.js
In this post, I would like to share a Modular Approach to create API generated with express.js. The modular approach which discussed here is having a module which can perform each and every task relevant to the API. It has following features. Read more “A Modular Approach to create API using Express.js and Node.js”
JavaScript
There are some instances where you need to debounce and avoid multiple clicks/taps on a button so that it will not generate the same action chain immediately with a consecutive click. An example would be an application with a touchscreen. If you click a button rapidly, that event will be generated more than once. As a solution, most of the time devs would block the UI until the action chain is completed. But this would be a bad experience if the user is blocked for any other interactions. A typical example can be a fetch call to update the state and if the invocation is asynchronous it could be causing more inconvenience.
Read more “Debounce and avoid multiple clicks event generation on React.js components using Lodash”
