AngularJS Overview Series - 2

Before reading this article, I highly recommend reading my previous part:

• AngularJS Overview Series - 1

Introduction



In the previous part of Hands on Agular Js-I we discussed the basics and the architecture of AngularJS and few directives. Here in this part we will check out the other important directives and how Angular interacts with Controller and how model is being done on the go. The directives we will discuss in this part of series are very important in order to start and feel the magic of Angular. Here, actually we go into the depth and controls of Angular. Let's have a look.

Angular directives

Here we start with the other important directives that would come in handy while working on the Angular.

ng-module

Angular modules are the most important directives, they define an angular application. They are the parent set for the other directives or functions of the application, like controllers. Controllers are always contained within the modules, along with other dependencies. This is the modular approach in Angular. Creating modules for separate sections segregates it and creates partition/module wise applications. The modules are defined syntactically as below:
As per the above snippet, we have created an angular module and assigned it to the variable named app. The module name is app-Services. The module is actually defined in the document function of a separate Module script file and reference is added to the file wherever required. The definition provided by the Angular Doc is that Module is required to configure the $injector and it contains the services, directives, controllers, and other dependencies. $injectors are the service used to retrieve the pre-defined object instances, invoke methods, and load the required modules.

ng-controller

This is another set of directives that defines the controller of the application, which controls the data of the application. They are simple objects defined under the scope of the module. There can be any number of controllers for a specific module. Controllers are defined syntactically as:
The above snippet is a simple controller defined under the module app-Services. The name of the controller is myFirstController and under its scope, two members are initialized, that is firstName & lastName. Thus, when an object of controller is created in the html, which will we see below:
Thus, as we see above, the html tag div has the scope for the Module we defined above and the controller defined for the module with the members firstName & lastName. When the controller is instantiated inside the scope of the div and Module, we have the right to access the data defined inside the controller function. $scope defined within the controller function is the context via which the model execution is implemented inside the controller. It actually acts as a watch on the model values while binding to the DOM element in the HTML. The $scope can also be used using the this object. The controller also accepts the $http to execute the http services in order to call the api's to get post and delete any data through the services. Let's see how the controller function can be separated from the declaration and defined as a function.