Just another tech blog!!

Hey, Back, again!! This time we will talk about some weird things which only happen in JavaScript. When I say weird, it means that if you come from a C++ or PHP or JAVA background it will be hard for you to digest that many concepts that we learned for those languages, and then think will apply in all the majority of programming languages out there, don't anymore apply here in JavaScript. A very classical and highly cited example is Objects and Inheritance without Classes, well I never imagined this could be done, but JavaScript does it, that too elegantly. Probably you are already aware that for Class JavaScript uses function(){} and not the conventional OOP Class. Well actually it uses or rather can use function for multiple other uses as well. Lets go through some of the amazing features of JavaScript. Loosely Typed Try this for a function in your browser console - If you look carefully here, func is a variable(in the way it is defined) which is used as a func...

Hi all, You must have definitely used the Profiling in Codeigniter and error_reporting many a times in Development and Testing environment, but I am sure you must have missed it on a real Production environment. As there are scenarios, where you want to quickly debug the Production application and find out what PHP errors is the application throwing, check the page profile, that too without putting the time and effort in replicating the whole production environment on your local machine, or perhaps a testing server. This small piece of code(we could perhaps call it a hack), which I have used in almost all of my CI applications, will make your life very easy, without losing anything on the security of the system. Following points, essentially sum up what exactly it does - Check for the dev(or root or admin, whichever name you use for the su access), if it is logged in, as we don't want others to see all the Profile data and other errors. Check for a specific query str...

Another Javascript library.....Argh!!!!! Please!!! I know guys, that you all have already come across scores of JavaScript libraries by now, but this one, my friends, is the one which you were missing while doing complex calculations and data processing. UnderscoreJS might seem as yet another JavaScript framework, which you might not be interested in learning, when jQuery is almost catering to all your JS needs. However, you might be mistaken here, as frameworks like jQuery/mootools/ExtJs/Ember/Backbone/Angular......are meant to action on the front-end or simply, the DOM. On the other hand, UnderscoreJS primarily focuses on easy handling of Objects and Arrays . Functions like filtering, array/object mapping, grouping, type checking etc, which you always longed for and which don't come along with the vanilla JavaScript, are available at your discretion with underscorejs. If you come from PHP background(like me), you know that PHP provides out-of-the-box functions like ar...

Hello Friends!! This post is dedicated to D3.js , which I came across a few months back. Prior to that, I always preferred Google Charts which catered to most of my charting needs. However, since I switched to D3.js I could not find a good reason to move back to Google Chart. If we take a very crude analogy, D3.js would be analogous to an Ubuntu of the OS world, while Google Charts could easily be a Windows 7(just that both of them are free in this case); in the sense that the control and the power the user(in our case the developer) gets from D3.js while working with it, is unmatchable . While Google Charts is simply too cool and simple for a free charting tool, but D3.js is a library which lets you create any chart that you could think and conceptualize, with so much of ease, and it lets you link any kind of interaction/control that you would want to put on events, on any of the elements of the chart. D3.js, like RaphaelJS and PaperJS is a library which is developed to ...

In this post I will show you how I converted my normal Codeigniter application into a multi-tenant system.(first step to a SaaS implementation) Note - This implementation is a separate DB multi-tenancy implementation. Lets say we have an up and running CI application name ci_app , with the directory structure like this ./application ./application/config ./application/...so many other important directories ./asset ./asset/js ./asset/images ./asset/css ./system ./index.php which is accessed through browser like http://localhost/ci_app So to implement the multi-tenant arch we are most concerned about the following files, and we will be editing them ./index.php ./application/config/config.php ./application/config/database.php And also we need to create a few new ones Create a tenant folder in your www root directory, lets say tenant_1 Cut the ./index.php from ci_app and paste it in tenant_1 directory  Create a blank file config.php in tenant_1 directory ...

Lets ponder on some details about Subversion to begin with Subversion is a free/open source version control system (VCS). That is, Subversion manages files and directories, and the changes made to them, over time. This allows you to recover older versions of your data or examine the history of how your data changed Subversion is different as compared to typical file server as   it remembers every change ever written to it —every change to every file, and even changes to the directory tree itself, such as the addition, deletion, and rearrangement of files and directories. Do you need it? If you need to archive old versions of files and directories, possibly resurrect them, or examine logs of how they've changed over time, then Subversion is exactly the right tool for you. If you need to collaborate with people on documents (usually over a network) and keep track of who made which changes, then Subversion is ...

Coupling and Cohesion are the two terms which very frequently occur together. Together they talk about the quality a module should have You might have got this advice n number of times that " cohesion is good and coupling is bad ", without actually going into the details as to what they mean and why one of them is bad and why the other one is good. Maybe because the one who is advising is not aware himself of the details and the one who is getting the advice is hesitant enough to ask, or may be they are not able to give good explanation. So in this post I am trying to give a good explanation on both, and hopefully good examples which you can co-relate with incidents and things in your daily life. As usual, lets start with checking what Wikipedia has to say on this On Coupling "In software engineering, coupling or dependency is the degree to which each program module relies on each one of the other modules." On Cohesion "Cohesion is a measur...