AngularJS – intro

AngularJS is a Javascript framework from Google. It’s goal is to display data in a web page based on the MVC, and related paradigms. It was built with the idea of being able to make the connections between, data and UI, apparent and easy to manage.

I just began with it a day ago, so take everything here with a grain of salt. I’m sure I’ll cringe at this a month from now. I’m just writing this all down to try and get it all straight in my own head.


Directives are attributes, that act as hooks for AngularJS. Assigning a Directive to a tag creates link to that tag and it’s contents to AngularJS.

AngularJS defines many built in Directives. These all begin with ng-. For example, ng-app, and ng-model. These can, optionally, be prepended with data- for validation if you like. For example: data-ng-app, and data-ng-model.

You can also write your own Directives.

Here area  few Directives.

The ng-app directive tells Angular which part of the page it should manage. It could be placed in the html tag to manage the entire page, or on the body or div tag to manage a smaller realm.

Where this tag is placed determines the document root for Angular. Placing the ng-app directive on a tag other than the <html> tag will limit the scope of the Angular app to that region of the page.

Include an optional module name as a value to this attribute. For example: ng-app=”moduleName”.

The ng-init Directive initializes data. Usually you’ll want to handle this with a Controller.

The ng-controller directive attaches a controller to DOM element. A controller is a Javascript object that will manage data displayed in that region.

The ng-repeat directive tells Angular to copy the elements within the repeat element a number of times. It will populate this “template” element with data from the model.

Loop with ng-repeat

  • {{name}}

Within ng-repeat Angular defines $index, $first, $middle, and $last. $index holds the the index of the repeated element. While $first, $middle and $last are booleans, true when the element is the first, middle or last element.


The {{}} defines a template expression. The {{ and }} can thought of as defining the area where Angular will write data. The expression inside can be thought of as modifying or defining how the data is written.

The ng-model attribute allows you to define connection from the DOM to model data. In the case of an input field modifying the input modifies the model data directly.

{{item.price | currency}}

The | defines a filter to be applied to the content of a {{}} template. There are several built in templates, and you can define your own. The example above formats item.price as currency.

The ng-click directive sets up a click action that will call on JS we define. The handler function should be part of the $scope of the controller that contains this ng-click.

Note that $index is a variable defined by ng-repeat.


The ng-bind attribute can be used to bind a view element to a model value. This works the same as use the {{}} template syntax. Where the {{}} syntax will show the {{}} for a moment when the page initially loads the ng-bind directive will not. Making this good for elements that will show initially.

Use ng-change to call a function defined in the $scope of the elements controller when a form element changes.

Use ng-submit to call a function when a form is submitted.

some text

Images and Anchors are special cases and have their own specific directives.

MVC – Model View Controller

MVC is a software design pattern that breaks functionality into three areas: Model, View, and Controller. This pattern is particularly suited to software that handles and manipulates data via user interface. Which makes it a good fit for Web apps. AngularJS turns HTML, CSS, and Javascript into a surprisingly good fit for this pattern.


Angular uses the MVC, or Model, View, Controller, paradigm. Where the Model represents data used by your program. For example, a list of user names, or a list of products with their price and description. The View is where data is displayed and represents the visual end of your program. The controller is the business side of your program. It contains the logic that manages data and facilitates translating data so it can be displayed by the View.

A Model can be as simple as a variable containing the number of times a button has been clicked. More often model data will be an array or object containing a list of values and properties.

A Controller might contain functions that controls the how a number is displayed. It might round the value off or format it any number of ways. More often the Controller will load an array of data and sort and filter before sending it to the View.

Views in Angular, are HTML. The view is essentially written in HTML and CSS, along with Angular’s templating system. Controllers are tied to views directly in the HTML as attribute names. This is a key feature of Angular that makes it unique.


Controllers handle processing model data.


The display data held by the model. Views in AngularJS are templates defined as snippets of HTML. These can be external files loaded into the app, or defined within the same file tags. Templates can all be defined as strings as part of a controller, directive or other module.


Model data should be defined in a “modules”. Use Angular’s module method to create a new module.


Services are singleton objects that provide global functionality to an app. Built in services begin with the $, such as $routeProvider, and $http.


Here’s the outline for an Angular page: