If it stinks, change it.

—Grandma Beck, discussing child-rearing philosophy

A way of thinking about writing a good piece of code is to remember that not everything out there is good.

Not all language features will help you write quality code. Some features may in fact be considered harmful (a code smell) and are hence discouraged.

OK, let’s rephrase in a more appropriate context

With great power of language features, comes great responsibility of deciding what not to use.

Let’s consider the case of getters and setters. They are common in most languages.You might say

What’s wrong about getters and setters?

Well everything!

Getters and setters break the very concept of encapsulation and data abstraction. They essentially give access to the internal implementations which should never happen in any good OO design. Only place where you might think of using getters is...

In the last blog I discussed about basics of JavaScript including objects, object properties, object creation etc. Continuing on the same basics now.

More on properties

The method Object.defineProperty() allows precise addition to or modification of a property on an object. As explained in the previous blog :

If the data property is created using Object.defineProperty, Object.defineProperties, or Object.create functions, the writable, enumerable, and configurable attributes are all set to true.

For Example :

var  person = {"Name" : "Dark Lord"};

Console Log

person.Name
"Dark Lord"
person.Name = "Ronan"
"Ronan"

If the object is created like :

var  person = Object.create({},
    "Name", { value : "Dark Lord"});

Since by default properties ARE NOT writable, enumerable or configurable, the person name cannot be changed. Name property will also not appear in Object.keys().

...

Today I hope to clear basic concepts related to integrating google maps in rails app. We will be using Gmaps4Rails gem for it. I will also discuss some common gotchas related to it.

First things first

First thing to go about adding google maps in your rails app would be to add these two lines in your Gemfile.

gem 'underscore-rails'
gem 'gmaps4rails'

underscore js is a dependency for Gmaps4Rails gem, hence it is included in Gemfile.

Next step is to install the newly added gems. Use bundle install to install the gems.

Add Map Javascript

Now you to have include the js files related to Gmaps4Rails and underscore js in application.js . To add the requirements for Gmaps4Rails, add below lines in application.js. Also you should have asset pipeline. If you are using coffeescript change the below lines accordingly.

//= require underscore
//= require gmaps/google

Next step is to add...

This is my first blog among a series of blog posts about javascript. The reasoning behind the blog series is to document and share the concepts I learn about javascript.

Lets start with the basics.

What’s JavaScript

Javascript is an object-oriented language with first-class functions. In a nutshell, JavaScript is a dynamic scripting language supporting prototype based object construction.

Objects

An object is a collection of properties and has a single prototype object. The prototype may be either an object or the null value.

JavaScript objects can be thought of as simple collections of name - value pairs. All primitive types except null and undefined are treated as objects.

Each name - value pair is called an property. That is property is named collection of attributes. The name part in any property is a JavaScript String and it is unique within that object. The value part can be...