What is AngularJS & Why to Choose AnguarJS
What is AngularJS
AngularJS is an open-source Javascript MVC (Model, View Controller) framework that is widely used for developing web applications, by AngularJS development company. it’s become one of the most standard frameworks at the present because of its distinctive options. The AngularJS framework is principally accustomed to develop single-page applications.
AngularJS has the flexibility to remodel the static HTML into a dynamic one. This framework enhances the capabilities of HTML with its inbuilt attributes, elements and also helps in making custom attributes using easy JavaScript.
AngularJS has been developed by a group of people at Google and it’s got an oversized community that makes it up so far. It continuously comes up with new options to satisfy market needs.
AngularJS Environment Setup:
This section deals with the concept known as fixing the AngularJS atmosphere and also deals with numerous directories. to line up the atmosphere, you wish to download the AngularJS. To download the AngularJS library, click here
Once you click on the on top of the link you’ll realize a choice to download AngularJS, click on that, and so it gets downloaded into your machine.
You will be displayed with the screen as shown below.
The on top of the screen can offer you two choices, which are:
- Downloading and hosting files regionally.
- CDN Access.
Download and host files locally:
- When you want this, you will be supplied with two options: one is heritage and also the alternative is the latest.
- We can even have an opportunity to travel beside the reduced or zipped version.
CDN Access:
You can even have access to CDN (Content Delivery Network) that will enable you to access the regional information centers. Here the CDN takes the responsibility to transfer the info between your own servers to a series of external servers. It additionally brings you an advantage; if a user of your site has already downloaded a duplicate of AngularJS from constant CDN, then there’s no got to re-download it. In this tutorial, we’ll be considering CDN Versions of the library.
Example: Here we are planning to discuss an example of a way to produce an HTML file using the AngularJS library.
<!doctype html>
<html>
<head>
<script src = "https://ajax.googleapis.com/ajax/libs/angularjs/1.5.2/angular.min.js"></script>
</head>
<body ng-app = "app1">
<div ng-controller = "HiController" >
<h2>Welcome {{helloTo.title}} to the world of Britwise!</h2>
</div>
<script>
angular.module("app1", [])
.controller("HiController", function($scope) {
$scope.helloTo = {};
$scope.helloTo.title = "Angular";
});
</script>
</body>
</html>
Include AngularJS
We insert the AngularJS JavaScript file in the HTML page so that we can utilize it.
<head>
<script src = "https://ajax.googleapis.com/ajax/libs/angularjs/1.5.2/angular.min.js"></script>
</head>
View
The view is this part
<div ng-controller = "HiController" >
<h2>Welcome {{helloTo.title}} to the world of Britwise!</h2>
</div>
ng-controller tells AngularJS which controller to utilize with this view. helloTo.title tells AngularJS to write the model value named helloTo.title in HTML at this location.
Controller
The controller part is
<script>
angular.module("app1", [])
.controller("HiController", function($scope) {
$scope.helloTo = {};
$scope.helloTo.title = "Angular";
});
</script>
Execution
Save the code as test.html and open it in any browser. You get to see the following output:
Welcome Angular to the world of Britwise!
A Program using AngularJS
Just to give an easy understanding of AngularJS, we are going to write a common “hello world” program here.
<html>
<body>
<script language = "javascript" type = "text/javascript">
<!--
document.write("Hello World!")
//-->
</script>
</body>
</html>
Output:Hello World!
AngularJS Expressions
AngularJS expressions are just like the JavaScript expressions that are enclosed inside the braces,
Example-{{expression}}. The expression may also be written as “ng-bind=expression”. AngularJS expressions are chiefly used to bind application knowledge to HTML. AngularJS takes responsibility to research, resolve expression and returns the result precisely within the same space wherever you have got given the expression.
AngularJS shares similar expressions like JavaScript, that are literals, operators, and variables. Let’s contemplate an instance over here: an expression } can return the result one and it’s sure to HTML.
Expression example:
<!DOCTYPE html>
<html >
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.16/angular.min.js"></script>
</head>
<body >
<h1>AngularJS Expression Demo:</h1>
<div ng-app>
4 + 4 = {{4 + 4}} <br />
4 - 4= {{4 - 4}} <br />
4 * 4 = {{4 * 4}} <br />
4/ 4 = {{4 / 4}}
</div>
</body>
</html>
Output:
4 + 4 = 8
4 – 4 = 0
4 * 4 = 16
4 / 4 = 1
AngularJS expressions are just like the JavaScript expressions however the below-mentioned reasons state the distinction between them.
- AngularJS cannot have a declaration like loops, conditions, or regular expressions. Eg:tenery, if-else, while loop, for loop, etc.
- AngularJS doesn’t contain the command or void expression.
- It cannot declare the functions.
- AngularJS cannot contain the expression to come back keyword.
AngularJS Directives:
Attributes are the markers that we tend to use in AngularJS to increase the capabilities of HTML. AngularJS comes with a group of intrinsical directives that facilitate the inefficient functioning of your applications. In AngularJS you’ll customize the directives in line with the wants of your application. Most of the directives in AngularJS can begin with ng-. ng stands for AngularJS.
The below-mentioned table contains a listing of vital inherent AngularJS directives.
| Directive | Description |
|---|---|
| ng-init | Initializes AngularJS variables |
| ng-app | Auto bootstrap AngularJS application |
| ng-controller | Attaches the controller of MVC to the view. |
| ng-model | Binds HTML control’s value to a property |
| ng-bind | It replaces the HTML value with the specified AngularJS expression |
| ng-show | It displays the elements based on the values of the specified expression. |
| ng-repeat | Repeats the HTML template once per each item. |
| ng-read only | It makes HTML element read only based on the specified expression |
Scope in AngularJS
A scope is an in-built object in AngularJS that has application ways and information. Here, you’ll have an opportunity to feature properties to a scope object within a controller operate and allot that with a function or worth to that.
The scope acts as a bridge between a controller and considers (HTML). It transfers the info from the controller to look at and vice versa.
Using AngularJS, one will produce and inject numerous scope objects connected to every controller in an application. So, the info and objects in one controller are quite completely different from others. So, one cannot access alternative applications.
AngularJS Events
AngularJS has its own HTML event directories in progress its advanced applications.
Using one or additional of the below-mentioned directives, you’ll add AngularJS event listeners to your HTML. These directives enable users to run AngularJS functionalities at user events.
- ng-blur
- ng-change
- ng-click
- ng-copy
- ng-cut
- ng-dblclick
- ng-focus
- ng-key down
- ng-keypress
- ng-key up
- ng-mouse down
- ng-mouseenter
- ng-mouse leave
- ng-mousemove
- ng-mouseover
- ng-mouse up
- ng-paste
AngularJS Service
AngularJS services are the Javascript functions for capital punishment specific tasks that are re-usable throughout the applying. It consists of services that serve numerous functions. for instance, the $http service helps in causing associate degree ajax request to the remote server. you’ll use angularJS to form a custom service for your application.
The majority of the services in AngularJS build interactions with the model, controller, and custom directives. There are some services that move with the view (UI) for the user-specific tasks.
The following table lists all the inbuilt AngularJS services
| $anchorScroll | $exceptionHandler | $interval | $rootScope |
| $cacheFactory | $httpParamSerializer | $location | $sce |
| $compile | $http | $parse | $timeout |
| $document | $interpolate | $rootElement | $sceDelegate |
| $animate | $filter | $locale | $templateRequest |
| $templateCache | $httpParamSerializerJQLike | $log | $window |
| $controller | $httpBackend | $q |
AngularJS Filters
Filters are utilized in AngularJS to format knowledge. AngularJS format permits us to format data and show data on UI without creating any modifications to the initial format.
Filters will be used with a directive or expression using pipe | sign as shown below.
{{expression | filterName:parameter }}
The below table contains the list of necessary Filters:
| Filter name | Description |
|---|---|
| currency | Format a number to a currency format |
| Filter | Selects a subset of items from an array |
| Lowercase | Converts string into lowercase |
| Date | Formates data into a specified format |
| Uppercase | Converts string into uppercase |
| ng-show | It displays the elements based on the values of the specified expression. |
| Json | Converts JavaScript object into Json string |
| Number | Formates the numeric data with fraction and comma. |
AngularJS Controllers
AngularJS applications are in the main hooked into the controllers to manage the flow of data in an application. The n-g controller directive is used to outline a controller. A controller contains functions and attributes/properties. $scope acts as a parameter for every controller.
AngularJS Factories
AngularJS factories are utilized for multiple things like server-side transmission via HTTP, to create changes across the controller, and to abstract models to persist the applying state. Angular factories facilitate in making reusable code blocks and options throughout an application.
AngularJS Routing
Using AngularJS, we will build one Page Application (SPA). it’s a web app that masses a single HTML page and dynamically updates the pages supporting the interactions of the user with the online app.
AngularJS utilizes the routing module, ngRoute, to support SPA. The routing model works supported the address. Whenever a user requests a particular URL, the routing engine catches that URL and renders the read supported the predefined routing principles.
AgularJS WorkFlow
Providing a framework for writing unit-testable code has been a core AngularJS goal from its initial release. AngularJS includes an elegant and complicated dependency widget, and every one AngularJS parts (controllers, directives, services, and filters) are created using the dependency widget. This ensures that your code’s dependencies are simple to extinguish as necessary for your tests.
Furthermore, the AngularJS team has developed various powerful checking tools like the destiny test runner, the drafting instrument, and ng situation integration testing frameworks. These bring the subtle multi-browser testing infrastructure that was previously possible just for massive corporations into the hands of the individual developer. In addition, AngularJS’s design and testing tools interface nicely with varied open supply JavaScript build and progress tools like Gulp and Grunt. With these tools, you’ll execute your tests seamlessly, tie in tools like code coverage and linting into your check execution, and even scaffold entirely new applications from scratch.
Core AngularJS is simply a library, however the testing and progress tools surrounding it build the AngularJS scheme as a full an innovative new paradigm for building browser-based shoppers. AngularJS coaching categories embody a lot of careful discussion of the AngularJS testing scheme and the differing types of testing ways you’ll use for your AngularJS applications.
Appliation of AngularJS
- It is an economical internet framework that helps in making an expensive internet Application (RIA)
- In AngularJS, developers will use the Model read Controller (MVC) way to write consumer-aspect applications.
- AngularJS is multi-browser compliant. It automatically handles the JavaScript code appropriate for every browser.
Advantages of AngularJS
- It provides the potential to make Single Page Application during a very clean and reparable method.
- It provides data binding capability to HTML.
- AngularJS code is unit testable.
- AngularJS uses dependency injection and build use of separation of issues.
- AngularJS provides reusable components.
Disadvantages of AngularJS
- Confusion
There are multiple ways to try to identical factor with AngularJS. Sometimes, it may be exhausting for novices to mention that the method is best for a task. Hence, it’s imperative for programmers to develop an understanding of the varied parts and the way they assist. - Lagging UI
If there are quite 2000 watchers, it will get the UI to severely lag. this suggests that the attainable quality of Angular Forms is restricted. This includes huge data grids and lists. - Name Clashes
With AngularJS, you don’t have the flexibility to compose several NG-apps on identical page. this may cause name clashes.
Again, these are some basic disadvantages. they’re far more benefits of the system, and people are what create it thus popular.
Why Choose AngularJS
- Quick Started
Getting started with AngularJS is very simple. All you would like to try to do is add some attributes to your HTML, and you’ll have your initial, tiny Angular app in a very matter of a couple of minutes. Isn’t that fascinating? - Time Saving
As mentioned on top of, all that AngularJS needs you to is split your application into multiple MVC elements. Once you have got done that, AngularJS can take over and perform the remainder of the functions for you. It saves you of the difficulty of writing another code to bind the MVC elements along once more. - Data Binding is simple
Do you keep in mind having created a text property on a model that you just would like certain into your UI? you’d recognize that it’s serious trouble. With AngularJS, though, this data binding happens sweat-free. Moreover, you’ll directly see what you kind within the span. - Declarative Expression of UI
Given that the UI with AngularJS is structured, it makes it easier for you to know similarly as manipulate. It’s value noting that designers are not any programmers. Hence, it’s vital to create their life easier. they will learn markup far more simply than programming. Hence, declarative expression of UI makes more sense for your team similarly as results for your purchasers.
Conclusion:
Finally, we’ve returned to the end of the AngularJS tutorial. I hope this blog has provided you with complete information on all the topics of AngularJS. Now, you need to have a transparent idea regarding the building blocks of AngularJS and the way it works. If you come upon any problem during this tutorial feel free to contact us, be happy to share with you the idea & information about AngularJS, if you want dedicated AngularJS developer, hire AngularJS developer we can respond at the earliest.