I am a full-stack web developer. I specialize in Blockchain and JavaScript. This is my personal blog where I write about programming and technologies that I learn and feel interesting to share.
Writing Upgradable Smart Contracts in Solidity
As you must be aware that smart contracts are immutable programs that run exactly as programmed without any third party interface. Smart contracts cannot be modified once they are deployed which is actually a feature of smart contracts but in some blockchain use-cases it may be needed to change the smart contracts interfaces and/or their […]
Calculating Nonce for Raw Transactions in Geth
You can simply use web3.eth.getTransactionCount to get the transaction nonce but it doesn’t include the transactions pending in the transaction pool. The purpose of this API is to simply retrieve total transactions count from the blockchain only till a particular block (by default latest block). So when you are pushing a lot of transactions from […]
Pointing Domain to AWS Elastic Load Balancing
Amazon ELB is an auto scalable load balancer that sits in front of EC2 instances and distributes traffic between them. Client communicates with ELB not with EC2 instances directly. When you create a ELB you get a domain name provided by Amazon AWS to make requests to the ELB. This domain name resolves to different […]
Find Recorded Audio File Location in Cordova
Many people use the Media Plugin to record audio in cordova apps. Here is an sample code that shows how to record: var extension = null; document.addEventListener("deviceready", function(){ if(device.platform == "iOS") { extension = ".wav"; } else if(device.platform […]
ES6 Reflect API Tutorial
This post is a part 18 of ECMAScript 6 Complete Tutorial post series. Object reflection is an language ability to able to inspect and manipulate object properties at runtime. JavaScript already had been supporting APIs for object reflection but these APIs were not organized under a namespace and also they threw exception when they fail […]
Express.js Middleware Tutorial
Developers who are new to Express often get confused with the difference between route handler and middleware. Therefore they also get confused with the difference between app.use(), app.all(), app.get(), app.post(), app.delete() and app.put() methods. In this tutorial I will explain the exact difference between a middleware and route handler. And also how to use the […]
Storing Data Locally in a Intel XDK App
This post is a part 53 of Intel XDK Complete Tutorial post series. I wrote an article on how to store data locally in cordova based apps. As Intel XDK builds cordova apps therefore the technique is same for Intel XDK also. The article is published by SitePoint.
Streaming File Uploads to Storage Server with Node.js
In this tutorial I will show how to stream a file uploaded by user to a file storage server(such as Amazon S3 or any other custom server) without storing file in a temporary directory. The advantage of this is that in case there is a lot of parallel uploads of large files then it prevents […]
Generate Unique Number in JavaScript
Here is the code that can generate a unique number in JavaScript. function uniqueNumber() { var date = Date.now(); if (date <= uniqueNumber.previous) { date = ++uniqueNumber.previous; } else { uniqueNumber.previous = date; } return […]
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@narayanprustyHi, I am a full-stack developer - focusing on JavaScript, WordPress, Blockchain, DevOps, Serverless and Cordova. You can outsource your app development to me.
Will get back to you soon!!!
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