AngularJS - Cody Good

Tutorial Basics



Introduction to AngularJS

AngularJS is a powerful JavaScript framework used in Single Page Application (SPA) projects. It is an open sourced front-end web application framework mostly maintained by Google. Web application frameworks are designed to support the development of web applications including web services and web resource, and aimed to automate the overhead associated with activities performed in web development. AngularJS aims to simplify the development and testing of applications by providing a framework for client-side model-view-controller (MVC) and model-view-viewmodel (MVVM) architectures. [wiki]

AngularJS works by reading HTML that has embedded custom tag attributes. The tag attributes are used as directives to bind together the input and output parts of the page to a model represented by standard JavaScript. This allows it all to be more responsive for users.

History of AngularJS

In 2009, Miško Hevery had an idea behind easy-to-make applications. At the time, he was working for a company called Brat Tech LLC, and was working to create a software behind an online JSON storage service. He, soon after, made the project public and released AngularJS as an open-source library.

At first AngularJS was just a side project that Hevery and, his coworker at the the time, Adam Abrons were working on. It was originally envisioned as a tool to allow web designers to interact with both the front-end and back-end. When Hevery joined the team at Google he started a project called Google Feedback which took nearly 17,000 lines of code during a six month period. Hevery challenged management that he could rewrite the application in no where near that amount of time using the project he and Abrons had built previously. Because Hevery successfully rewrote the Google Feedback in just three weeks and right around 1,500 lines of code, his managers were impressed and allowed the development of AngularJS to begin. [aw]

AngularJS version 1.0 was released in 2012. It is now supported by Google and has many different versions. Coders all over the world can thank Hevery for and easy-to-use application that makes life a little easier.

Overview of AngularJS

Behind every problem is a solution. AngularJS is no different from this mainstream idea, because it is the solution to a problem that people have been working to solve. The problem being, complex code that has to be managed in multiple places. For instance, when creating a simple table of items and variables, both the HTML (View) and the data (Model) must be updated separately. AngularJS has a concept called MV* that is the basis behind the framework. Its purpose is to bind the model and the view using what ever means necessary. The following is an introduction to simple AngularJS code and how the framework operates. Each section includes a small explanation, a code sample, and a brief description on what the code is doing behind the scenes. [yt]

Setting Up an AngularJS Application [w3]

There are a few important details when setting up an application. These details allow the AngularJS to operate and effectively bind the model and the view for user efficiency.

The first thing is loading the library. This is a very simple task and is recommended to be done in either the head tag or at the beginning of the body tag.

<!DOCTYPE html>
<html lang="en-us">
<script src=""></script>

Once the library is loaded, the next step is to create a module. AngularJS modules define an application and are a container for different parts, as well as, controllers for the application. Modules are created by using the AngularJS function angular.module.

The module is created in JavaScript inside an application variable. As such:

var exApp = angular.module('exApp', []);

As discussed before, the purpose of AngularJS was to communicate between the model and view efficiently, so the module must then connect to the HTML. This is done using an attribute called ng-app. It is recommended that the user put this attribute as soon as possible in the HTML, in the original html tag, for instance, because of the way it works. The attribute will search the HTML code for anything that matches AngularJS code and convert it connect it to the variable created in the JavaScript. So, if the module is initiated at the beginning, then the entire HTML file will be overviewed for AngularJS. This code looks like the following:

<!DOCTYPE html>
<html lang="en-us" ng-app="exApp">
<script src=""></script>

With this, the rest of the code that is included in the HTML will be connected to the var exApp = angular.module('exApp', []);. Next, controllers come into play.

Controllers [w3]

As redudant as it sounds, controllers control the data in AngularJS applications. Meaning that when the controller is created under the module, it will control what ever HTML it is connected to and the AngularJS will keep these two things bound no matter what. The controllers have properties and methods, as well as, include functions, so when writing the JavaScript code it looks like the following.

exApp.controller('exController', function() {


For this example, the controller is named exController and is found under the exApp module. In order to connect it will HTML, the following code is then used.

<!DOCTYPE html>
<html lang="en-us" ng-app="exApp">
<script src=""></script>
        <div ng-controller="exController">

In the example above, notice that an attribute ng-controller is used to associate back to the module where exController can be found. With this, exController now "controls" everything inside of the div tag by means of the function inside of the exController. Before continuing to build, it's important to understand the idea behind attributes and the different kinds.

Tag Attributes [tp]

Attributes are used in AngularJS as directives to bind input and output. The developers of AngularJS included many preprogrammed attributes in the framework, but users can also create custom attributes. Later some of the main attributes will be introduced, but the following is what a custom attribute might look like inside a simple header.

<h1 ng-call="Hello">Phone Number</h1>

The HTML only prints the header "Phone Call" on the page, but by using the AngularJS custom attribute ng-call, "Hello" prints on the console. Very simple communication between the HTML and JavaScript.

Some of the more common attributes (or directives) include:
  • ng-app - defines an AngularJS application
  • ng-model - binds the value of HTML controls to application data
  • ng-init - initializes application data
  • ng-repeat directive repeats an HTML element
  • ng-bind - binds application data to the HTML view

AngularJS Expressions [w3]

Expressions are used to bind data to HTML in AngularJS. First the application resolves the expression and then it returns the result as the expression is written. Expressions can contain literals, operators, variables, etc. Expressions can either be written in double braces {{ expression }} or inside an attribute ng-init = "expression".

The following is an example of how an expression can be used inside of an attribute to change the color of a box on the browser. The user can edit the expression in the div tag and the AngularJS will produce the appropriate new color on the screen.

<!DOCTYPE html>
<script src=""></script>


<div ng-app="" ng-init="color='red'">
<input style="background-color:{{color}}" ng-model="color" value="{{color}}">



This is what the code results in:



AngularJS is a very powerful tool that programmers are able to benefit from. Even though this tutorial is brief, there are many out on the web that include much more detailed step-by-step workshops to help users better understand the framework. One of the most important aspects that AngularJS brings to the table is simplicity and efficiency. Often times, coding can be a very challenging and rigorous task. With many complications of what is the right way to code things and which way is fastest, AngularJS stands out by making the development and testing of applications easier. The framework that Hevery and Abrons started working on in 2009, now provides for client-side MVC and MVVM architectures everywhere. With the ability to bind the model and the view that allows for faster response times for users, AngularJS is a very intuitive and problem-solving application.


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