Why I Use Angular.js For Latest Web Projects ?

AngularJS is a relatively new JavaScript framework by Google, designed to make your front-end development as easy as possible. There are plenty of frameworks and plugins available. As such, it can sometimes prove difficult to sift through all of the noise to find useful tools , those frameworks nowadays are simply a bundling of existing tools. They are an integrated tool set, but not very elegant. Angular is the next generation framework where each tool was designed to work with every other tool in an interconnected way.

Below are reasons why I am using Angular and you should use it too:

Gives Structure to Your App

Normally, when we write JavaScript there is no well defined structure. While this can work for small apps, this is clearly not suitable for large scale apps. With AngularJS you can structure your source code by following either the MVC (Model-View-Controller) or MVVM (Model-View-Viewmodel) pattern. AngularJS is a MVW framework where W stands for Whatever works for you. You can organize your code into modules, which dramatically improves the testability and maintainability of your app.

Write less code

All the points up till now mean that you get to write less code. You don’t have to write your own MVC pipeline. The view is defined using HTML, which is more concise. Data models are simpler to write without getters/setters. Data-binding means you don’t have to put data into the view manually. Since directives are separate from app code, they can be written by another team in parallel with minimal integration issues. Filters allow you to manipulate data on the view level without changing your controllers. Yes, this is sort of a summary bullet point, but writing less code is a big deal!

DOM Manipulation - It's Now Very Easy!

Traditionally, the view modifies the DOM to present data and manipulates the DOM (or invokes jQuery) to add behavior. With Angular, DOM manipulation code should be inside directives and not in the view. Angular sees the view as just another HTML page with placeholders for data. This way of looking at the view pairs nicely with user interface designers.

By abstracting out the DOM manipulations and jQuery calls, user interface designers are able to focus on the view without those distractions.

By making your MVC app purely about presenting business data into views, and not have to worry about manipulating DOM, web app development suddenly became more fun.

A Declarative User Interface.

Angular uses HTML to define the app’s user interface. HTML is a declarative language which is more intuitive and less convoluted than defining the interface procedurally in JavaScript. HTML is also less brittle to reorganize than an interface written in JavaScript, meaning things are less likely to break. Plus you can bring in many more UI developers when the view is written in HTML.

HTML is also used to determine the execution of the app. Special attributes in the HTML determine which controllers to use for each element. These attributes determine “what” gets loaded, but not “how”. This declarative approach greatly simplifies app development in a sort of WYSIWYG (what you see is what you get) way. Rather than spending time on how the program flows and what should get loaded first, you simply define what you want and Angular will take care of the dependencies.

Data Models

Data models in Angular are plain old JavaScript objects and don’t require extraneous getter and setter functions. You can add and change properties directly on it and loop over objects and arrays at will. Your code will look much cleaner and more intuitive, the way mother nature intended.

Traditional data models are the gatekeepers of data and are responsible for data persistence and server syncing. Those data models behave like smart data providers. But since Angular’s data models are plain objects, they behave more like a cork board. A cork board is nothing more than a temporary storage area for people to put and retrieve data. However, Angular’s cork boards work closely with a controller and view. To differentiate it from the traditional sense of data models, Angular calls them “scopes”.

All properties found on the scope object are automatically bound to the view by Angular. Meaning, Angular quietly watches for changes to these properties and updates the view automatically.

The scope has no data to begin with and relies on the controller to feed it data according to business logic needs.

Two-way Data Binding

Data binding is certainly one the best features in AngularJS. You can declaratively bind your models to HTML elements. When the models change, the view is automatically updated and vice versa. This hugely reduces the amount of boilerplate code traditionally written to keep the model and view in sync.

Directives

Directives are Angular’s way of bringing additional functionality to HTML. Imagine a world where HTML has so many rich elements (for example , , , etc.) that we never have to manipulate the DOM to simulate them. All that our app needs to do is to assign attributes to elements to get any functionality out of the box.

Directives achieve this by enabling us to invent our own HTML elements. By putting all our DOM manipulation code into directives, we can separate them out of our MVC app. This allows our MVC app to only concern itself with updating the view with new data. How the view subsequently behaves is up to the directives.

Directives come in the form of custom HTML elements

<myticker></myticker>

custom attributes

<div data-myticker></div>

and custom class names

<div class="myticker"></div>

allowing them to be used like regular HTML elements.

Directives are designed to be standalone reusable elements separate from your app. In fact, if a particular element becomes adopted by the HTML5 standard, it should be as simple as removing your custom directive, and your app should behave exactly the same without needing to change your app.

Remember, as a rule of thumb, your controller should not manipulate the DOM directly. All DOM manipulations should be performed by directives.

Filters

Filters filter the data before they reach the view and can involve something as simple as formatting decimal places on a number, reversing the order of an array, filtering an array based on a parameter, or implementing pagination. Filters are designed to be standalone functions that are separate from your app, similar to Directives, but are only concerned with data transformations.

Filters are so resourceful that it is possible to create a sortable HTML table using only filters without writing any JavaScript.

Services

If controllers are so simple, then where should all the heavy lifting be performed? Angular introduces Services to do just that.

Services are exactly what they sound like. They don’t get involved with the MVC of your app, but simply provide an outward API to expose whatever you want it to expose. Most of the time it syncs up to a server to maintain an offline data store and exposes methods to push and pull data to and from a server. Or it can be used to create a resource sharing service that allows multiple controllers to share the same resources.

Services are designed to be standalone objects separate from your app and allow your controller to be remain lean and dedicated to the view and scope that it is assigned to. Of course, implementing services is not required and it is perfectly acceptable to do some light lifting inside your controller to avoid over complexity.

Context aware communication

A PubSub system is a pretty common tool that allows for decoupled communication. Most PubSub implementations on the web are not context aware. Sometimes you want a PubSub message to be readable only by children of a particular node, or only readable by the ancestors of a particular child. In other words, sometimes you don’t want unrelated MVC components to be reading your messages.

The PubSub system in Angular is precisely that. will send a message to all children controllers, while will send a message to all ancestors.

But PubSub isn’t the only way to communicate between controllers. In fact, if all you’re doing is telling other controllers to update their views when a property changes, you should be relying on data-binding. We already know that the view can be bound to properties on the current scope. But what I didn’t tell you is that scopes inherit the properties of their parent scopes. That means if a property exists on the parent scope, and a child scope modifies it, then all other scopes that inherit from the same parent will also see the same modification and their views will be updated automatically by Angular! This automated way beats using PubSub any day.

Unit Testing

What description of Angular would be complete without talking about it’s unit testing readiness? The whole of Angular is linked together by Dependency Injection (DI). It’s what it uses to manage your controllers and scopes. Because all your controllers depend on DI to pass it information, Angular’s unit tests are able to usurp DI to perform unit testing by injecting mock data into your controller and measuring the output and behavior. In fact, Angular already has a mock HTTP provider to inject fake server responses into controllers.

But wait that’s not all!, AngularJS also offers many more useful features like routing, animations and much more! . If you're looking for a robust, well-maintained framework for any sized project, I strongly recommend that you take a look at AngularJS .

Thanks for reading!

About the Author

More on Sandip here at LinkedIn

Sandip Das is a tech start-up adviser and has served many international  IT firms , tech-entrepreneurs as Individual IT consultant / Sr. Web Application developer / JavaScript Architect , worked as a team member , helped in development and in making IT decision .

His desire is to help both the tech-entrepreneurs & team to help build awesome web based products , make team more knowledgeable , add new Ideas to give WOW expression in product .