Sandny Blog

Query definition in GraphQL and frequent errors with Apollo…

February 18, 2019March 11, 2019
by Coder Kai

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,

Most of the error logs are not descriptive and makes no clue on where the real error is.
There can be so many different mistakes in coding the queries and difficulty in keeping on track of it.

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 Data Structures

January 25, 2019January 18, 2020
by Coder Kai

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.

1. List

List can be define as [ element 1 ; element 2 ; element 3; … ].

OCaml

January 24, 2019January 18, 2020
by Coder Kai

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.

What is Functional Language?

OCaml

Why did Facebook pick OCaml?

December 18, 2018January 18, 2020
by Coder Kai

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.

AppSync

AppSync GraphQL Web App with AWS Amplify and IAM…

September 24, 2018September 25, 2018
by Coder Kai

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.

AppSync

Query records for a list of keys in GraphQL…

September 3, 2018
by Coder Kai

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

AppSync

How to mutate AWS GraphQL using AWS Lambda

August 26, 2018September 5, 2018
by Coder Kai

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

Use AWS GraphQL for React Native Message App

June 28, 2018September 3, 2018
by Coder Kai

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

How to use antd components without the whole library

February 26, 2018August 29, 2018
by Coder Kai

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

A Modular Approach to create API using Express.js and…

November 5, 2017August 26, 2018
by Coder Kai

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

Debounce and avoid multiple clicks event generation on React.js…

November 1, 2017August 26, 2018
by Coder Kai

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.

Express.js

babel + express.js + node.js + nodemon to build…

October 30, 2017August 26, 2018
by Coder Kai

This guide will take you through on how to use nodemon to build api which is simply to create a web app with node.js + express.js in a babel environment. Often we need to use babel to increase readability of our code. And nodemon was used to watch and re-build the project and serve it consistently. Read more “babel + express.js + node.js + nodemon to build API with hot reloading” →

Java

How to create a Vertx EventBus js client and…

October 21, 2017September 4, 2018
by Coder Kai

Recently I came across Vertx toolkit (http://vertx.io/docs/) when I was building an API. What I needed was to build a simple server to connect a javascript app and transfer message in between. So before going into more details lets discuss what Vertx toolkit has to offer and then create a Vertx Eventbus js client. Read more “How to create a Vertx EventBus js client and use it with a web server with CORS” →

Java

How to create a neo4j BoltDriver Datasource and connect…

October 19, 2017November 21, 2019
by Coder Kai

I wanted to test the neo4j database access using a data source defined in Wildfly server. I used Wildfly 10.1.0 release. I wanted to use the driver with bolt protocol to observe the performance when using it. Read more “How to create a neo4j BoltDriver Datasource and connect it with a web app” →

EmberJS

Adaptation of js apps and how predesigned abstractions could…

October 18, 2017November 21, 2019
by Coder Kai

Through the last couple of years, javascript has drastically changed and the many developers have tried using different approaches to define their application structure and abstractions in a way which is best suits at that time. There is one thing to highlight which I intend to discuss, “Rapid Changes”. So how can a developer or an architect withstand these rapid changes to frameworks and awesome libraries introduced each day in the js context? With my experience, I learned a couple of facts which I think is necessary to embrace these changes until js development becomes structurally solid as engineered buildings. Read more “Adaptation of js apps and how predesigned abstractions could burn you” →

JavaScript

Higher order component wrappers using React.js and reusable components.

October 4, 2017November 21, 2019
by Coder Kai

Recently I happened to create a middle panel where different types of components could be rendered on top it. So the idea is, the panel should be a <div> wrapper around the middle content. For this kind of situation, higher order functions with components could come in handy to use. Read more “Higher order component wrappers using React.js and reusable components.” →

JavaScript

Add SASS in webpack React Redux project

September 3, 2017December 26, 2019
by Coder Kai

This guide will simply cover to embed SASS support in React.js project.

First, install node-sass and sass-loader npm packages.

Yarn: yarn add sass-loader --dev
      yarn add node-sass 
    
NPM: npm install node-sass
     npm install sass-loader --save-dev

machine learning

Use JBLAS library in spark-shell

June 28, 2017November 21, 2019
by Coder Kai

Recently when I was using spark-shell I couldn’t use JBLAS library which has DoubleMatrix classes. After a quick go through I could use it using –package option.

Run spark-shell using following command

./spark-shell  --packages org.jblas:jblas:1.2.4-SNAPSHOT --driver-memory 4G

If the package lookup can’t find it in the local maven repositories try build JBLAS once and the library will be available

git clone https://github.com/mikiobraun/jblas.git
cd jblas
mvn install

Server

How to create a XA datasource in Wildfly 10…

May 21, 2017August 29, 2018
by Coder Kai

I wanted to use mysql XA-Datasource to connect mysql datasources using the Wildfly 10 server. XA Datasources are better as it can span multiple resources.

Embedded

Installing Nios II Eclipse on Ubuntu

May 20, 2017December 26, 2019
by Coder Kai

When you want to use Altera Quartus and other software on Linux, sometimes it becomes tricky. It will show an error