Author Archives: Ajitesh Kumar

Ajitesh Kumar

I have been recently working in the area of Data analytics including Data Science and Machine Learning / Deep Learning. I am also passionate about different technologies including programming languages such as Java/JEE, Javascript, Python, R, Julia, etc, and technologies such as Blockchain, mobile computing, cloud-native technologies, application security, cloud computing platforms, big data, etc. For latest updates and blogs, follow us on Twitter. I would love to connect with you on Linkedin. Check out my latest book titled as First Principles Thinking: Building winning products using first principles thinking

What is Difference Between Select and Datalist?

The article represents the key difference between Select and Datalist and emphasize on related best practices. Following are key differences Select is an form input type while Datalist isn’t Select input element presents options for the users from which they need to select one of them. On the otherhand, Datalist presents a list of suggested values to the associated input form (text) field and users are free to select one of those suggested values or type in their own value. With Select, users may have to scan a long list for selecting one of the values, while with Datalist, the values are provided as hints and users ain’t bound to …

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Posted in UI, Web. Tagged with .

AngularJS & Bootstrap Hello World UI Template

angularjs bootstrap

The article is a placeholder for the copy & paste code for AngularJS and Bootstrap. If one wants to quickly get started with AngularJS and Bootstrap, one may want to bookmark this page. Points to pay attention: AngularJS script referenced from Google hosted libraries Bootstrap scripts and CSS files from bootstrapcdn   <!DOCTYPE html> <html ng-app=”helloApp”> <head> <title>HelloWorld</title> <link rel=”stylesheet” href=”//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css”> <script src=”//ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js”></script> <script src=”//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js”></script> <script> var helloApp = angular.module( “helloApp”, [] ); helloApp.controller( “HelloCtrl”, [ ‘$scope’, function($scope) { $scope.name = “ajitesh shukla”; }]); </script> </head> <body ng-controller=”HelloCtrl”> <div class=”page-header”> <h1>Hello World Sample Program</h1> </div> <div> <form class=”form-horizontal” role=”form”> <div class=”form-group”> <label class=”col-md-2 control-label”>Type Your Name</label> <div class=”col-md-4″> <input type=”text” …

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Posted in Javascript, UI. Tagged with , .

7 Reasons Why One Should Try Chrome Dev Editor (CDE)

CDE - Chrome Dev Editor

The article presents information on Chrome Dev Editor which was made available to developers in Google IO 2014 event. I played with it and checked various different capabilities. If you think I missed on one or more cool features, please feel free to shout. Also, created a sample AngularJS Hello World program. Following picture represents the following: Ability to clone GIT ptoject Ability to create javascript web apps. Shown is AngularJS helloworld app. Well, frankly speaking, to work with Javascript Web Apps, it is same like any other text editor. However, it brings following benefits to the table which makes it very attractive and WORTH A SPIN: IDE Features: With …

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Posted in Tools, Web. Tagged with , .

AngularJS – How to Post JSON Data using AJAX & SpringMVC

The article presents code samples that one could use to quickly get started with posting JSON data using AngularJS  $http service while working with SpringMVC web application. The demo for the code below could be found on this page, http://hello-angularjs.appspot.com/angularjs-http-service-ajax-post-json-data-code-example.  Earlier, I posted this article where one could post the html data (text/html) using AJAX & SpringMVC. Following are key steps: Create SpringMVC Controller methods and a POJO Create AngularJS Controller Method Create View   SpringMVC Controller methods and a POJO Following are key steps: Create a controller method to access the page consisting of UI that will be posting using AJAX Create a controller method that shall be receiving the …

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Posted in Java, Javascript. Tagged with , , , .

AngularJS & SpringMVC – How to Fix 415 Unsupported Media Type Error

  The article presents tips on how to fix 415 Unsupported Media Type error while working with AngularJS & SpringMVC web application when one tries to POST JSON data using $http service. The sole reason I wanted to write this blog is to help many of my friends who are most likely to hit this one when they work on posting JSON data to SpringMVC web controller using $http service. Possible scenarios: Most likely, you might not have included Jackson libraries in the classpath. Thus, go to http://wiki.fasterxml.com/JacksonDownload and download all the jar files. Alternatively, get slightly back-dated version of all of the libraries in one jar file from http://www.java2s.com/Code/Jar/j/Downloadjacksonall199jar.htm. …

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Posted in Java, Javascript. Tagged with , , , .

AngularJS – How to POST Data using AJAX & Spring MVC – Part 1

The article presents the code example that one may use to post data to server using AngularJS $http service, while working with Spring MVC web application. The same is demonstrated in the following page: http://hello-angularjs.appspot.com/angularjs-http-service-ajax-post-code-example. This article is first in the series of articles on different techniques that could be used to POST different formats of data to the server when working with AngularJS and Spring MVC. In this article, the code samples demonstrate how to post plain HTML text data (text/html) format to the server. Following are key steps: Create Spring MVC web controllers methods Create AngularJS controller method using $http service to post data Create view to receive input …

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Posted in Java, Javascript. Tagged with , , , .

AngularJS – How to Get Data from AJAX & Spring MVC

  The article presents steps one need to code in order to get data from server using XMLHttpRequest (XHR) while working with Spring MVC Java web application. Watch the demo and code samples at http://hello-angularjs.appspot.com/angularjs-http-service-ajax-get-code-example. Following are key steps: Write two methods in Spring MVC controller, one to load the page and other to serve AJAX request Write AngularJS code to get the data (model) in the controller method using $http  Write the view to display the data   Spring MVC Controller Methods Following are two methods one need to write in the Spring MVC Controller: Method below serves the page, views/httpservice_get.jsp when accessed using the following URL: http://hello-angularjs.appspot.com/angularjs-http-service-ajax-get-code-example. Try …

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Posted in Java, Javascript. Tagged with , , , .

OWASP Broken Authentication and Session Management Example

The article presents an example on one of the top OWASP vulnerability related with authentication and session management. This is termed as “Broken Authentication and Session Management”. To know more about this vulnerability and related details, visit OWASP page for broken authentication and session management.   I was surfing a website, http://www.99acres.com, few days back and tried to retrieve my password using “Forgot Password” page. As I entered my username, I was amazed to see my email address shown there. I, then, tried another name such as “karthik” and following was the message:“An email has been sent to karthiksundaram@gmail.com. Please click on the link provided in the email to create …

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Posted in Application Security. Tagged with .

AngularJS Coding Best Practices

angularjs

The article lists down some of the best practices that would be useful for developers while they are coding with AngularJS. These are out of my own experiences while working on AngularJS and do not warranty the entire list. I am sure there can be more to this list and thus, request my readers to suggest/comment such that they could be added to the list below. Found some of the following pages which presents a set of good practices you would want to refer. Thanks to the readers for the valuable contribution. AngularJS Style Guide App Structure Best practices   Initialization One should try and place the <script> tag including …

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Posted in Javascript. Tagged with , .

How to Become a Technical Architect or an IT Architect?

The article presents a perspective on what is required to be done to become a Software Architect given you are currently playing the role of a software developer or a senior software developer. I have put up this blog as an answer to a related question put up by one of the vitalflux.com esteemed reader. Well, there is no right or wrong answer to this question. There can only be different perspectives. In case you have different views, please feel free to comment. Before I go on to present my perspective, check out some of the following links to understand what is Software Architecture? http://en.wikipedia.org/wiki/Software_architecture http://www.sei.cmu.edu/architecture/ http://www.ibm.com/developerworks/rational/library/feb06/eeles/   Different Designations …

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Posted in Architecture. Tagged with .

AngularJS Interview Questions – Questions Set 1

ATG interview questions

The article lists down some of the interview questions that could be asked in relation with AngularJS. Most of the answers can be found on the home site, http://www.angularjs.org. Following are another set of questions that have already been published earlier. Also, feel free to take tests on this page. Interview questions – Set 2 Interview questions – Set 3 Interview questions – Set 4 Questions Set What is notion of directives in AngularJS? Ans: https://docs.angularjs.org/guide/directive Name some of the most commonly used directives? What is uage of ng-app, ng-controller, ng-view, ng-model etc? Ans: https://docs.angularjs.org/api Explain how MVC is achieved with AngularJS? What are the benefits of client-side MVC, in general? Ans: https://docs.angularjs.org/guide/controller …

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Posted in Interview questions, Javascript. Tagged with .

AngularJS – 7 Steps for Unit Testing AngularJS Scripts with Jasmine

This article presents instructions on what would it take to create a setup and run unit testing for your AngularJS scripts using Jasmine framework. I shall be presenting various samples on my AngularJS website, http://hello-angularjs.appspot.com. Sorry for the typos in this article and please feel free to suggest/add any points if I missed them out.   Following are key steps:  Learn Jasmine Create Unit Tests using Jasmine Download and install NodeJS Download & Install Karma Configure Karma Place Scripts Appropriately Execute Tests   Learn Jasmine Jasmine, one of the very popular Javascript unit testing framework, can be used for unit testing one’s AngularJS scripts. As a matter of fact, Angular …

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Posted in Javascript, UI, Unit Testing. Tagged with , , .

Javascript Unit Testing using Jasmine – Code Examples

jasmine unit testing framework

The article lists down some of the unit tests samples for testing Javascript code. The unit tests in this article tests the javascript code presented in this article, “What are Objects in Javascript?”. Before presenting code samples, lets try and understand what is Jasmine? As on the Jasmine website, it is defined as a behavior-driven development framework for testing JavaScript code. It does not depend on any other JavaScript frameworks. It does not require a DOM. And it has a clean, obvious syntax so that you can easily write tests.  By what I learnt so far, I could vouch for the statement “And it has a clean, obvious syntax so that …

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Posted in Javascript, Testing. Tagged with , .

What are Objects in Javascript ? – Code Samples

Wrote this article on Objects & Javascript for future reference. Codecademy.org is my favorite go-to-place for learning Javascript. Javascript Objects could be defined in following three manners. Objects created as Variables Objects created using new Object() Objects created using Constructor   Objects created as Variables // Defining object as a variable var School = { name: “DAV Public School”, studentsCount: 600, admissionOpen: false, }; School.isAdmissionOpen = function() { return this.admissionOpen; }; School.setAdmissionStatus = function( openOrClosed ) { this.admissionOpen = openOrClosed; };   Objects created using new Object() In the example below, College is an object type. // Creating object using new Object() var College = new Object(); College.name = “IIT …

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Posted in Javascript. Tagged with , .

AngularJS – How to Create Single Page Application – Code Examples

  This article presents details on how one could create single page app using AngularJS.  You could check out this page (http://hello-angularjs.appspot.com/spa) for demo. This page is created using AngularJS and Spring MVC. It consists of notes and sample codes along with a couple of views being loaded on the same page based on different URL routes.Following is touched upon in this article for creating SPA using AngularJS. What is Single-Page application? Routing in AngularJS – Key for SPA Code Sample – Single Page App Code Sample – Routing Some of the key AngularJS concepts that got demonstrated in this article and the related demo page are following: Routing Directives Templating …

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Posted in Javascript. Tagged with , .

AngularJS Key Concepts – Part 1

angularjs

The article represents certain key concepts of AngularJS javascript framework. I shall be writing further articles presenting my learning as I go ahead. AngularJS is a great (so-called Super-heroic) framework if you want to build single page applications (SPA) consisting of multiple views (smaller web pages so to say). That said, it is not limited to SPAs and could be used with any kind of web applications. If you have worked in past with JQuery, you would be amazed to see the simplicity that AngularJS brings on the table with respect to DOM manipulation. Just this feature has got me on board with Angular. Modular framework: Angular is a modular …

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Posted in Javascript. Tagged with , .