AngularJS Overview and APIs

AngularJS Overview

• AngularJS is a powerful web development framework designed for creating Rich Internet Applications (RIAs).
• It implements the Model-View-Controller (MVC) architecture for client-side applications.
• AngularJS is open-source and licensed under the Apache License version 2.0.
• Automatically manages JavaScript code compatibility across different browsers.

AngularJS APIs

• AngularJS documentation is structured into modules, which include components like directives, services, filters, providers, templates, global APIs, and testing mocks.
• It provides a comprehensive guide on various topics and includes external resources for further learning.

AngularJS Animations

• Supports animated transitions via CSS for common directives such as ngRepeat, ngSwitch, and ngView.
• Custom animations can be implemented using the $animate service.
• Animation triggers occur during different lifecycle phases of directives, capable of CSS Transitions, CSS Keyframe Animations, or JavaScript callback Animations.

AJAX and Web Applications

• AJAX (Asynchronous JavaScript and XML) allows web applications to send and receive data to/from a server without reloading the page.
• Utilizes the XMLHttpRequest object to communicate with servers, improving the user experience by preventing page reloads.
• Common uses include live search suggestions and dynamic content loading while the user interacts with the application.

AJAX Process Steps

• User interaction triggers a JavaScript request to the XMLHttpRequest object.
• An HTTP request is sent to the server.
• Server processes the request and interacts with the database.
• Data is sent back in XML or JSON format, which is then processed by the JavaScript callback function.
• Frontend updates dynamically without a full page load.

Single Page Applications (SPAs)

• AJAX facilitates the development of SPAs, where content updates without a full page change, enhancing usability.
• Navigation in SPAs typically retains the main interface on the same page while only changing specific content elements.

Popular JavaScript Frameworks for SPAs

• Angular
• React
• Ember
• Aurelia
• Vue.js
• Cycle.js
• Backbone.js

AngularJS Features

• Data binding capabilities enhance user interactivity.
• Supports dependency injection to promote separation of concerns and reusability.
• REDUCES the amount of code required while maximizing functionality.
• Compatible with major browsers and mobile devices.

Advantages of AngularJS

• Streamlined creation of Single Page Applications (SPAs).
• Offers rich, responsive user experiences through data binding.
• Code is unit-testable, promoting robust application designs.

Disadvantages of AngularJS

• Security vulnerabilities may arise, leading to potential risks.
• Limited degradability compared to some frameworks.

AngularJS Expressions

• Can be written using double braces: {{ expression }}.
• Also usable within directives to embed expressions.

AngularJS Directives

• AngularJS includes built-in directives and allows for user-defined directives, enhancing web app functionality.
• Directives are extended HTML attributes prefixed with ng-.
• ng-app initializes an AngularJS application right upon page load.
• ng-init sets initial values for application data.
• ng-model binds HTML input controls (input, select, textarea) to application data, providing:
  • Type validation (e.g., number, email, required).
  • Status tracking (e.g., invalid, dirty, touched, error).
  • CSS class application for HTML elements associated with forms.
• The ng-repeat directive can repeat HTML elements based on data arrays.

Creating New Directives

• New directives are created using the .directive function.
• Directives should follow camel case naming (e.g., simpleTestDirective) and use a hyphenated name when invoked (e.g., simple-test-directive).
• Directives can be triggered via:
  • Element name
  • Attributes
  • Class
  • Comment
• Restrict values for directive usage:
  • E: Element
  • A: Attribute
  • C: Class
  • M: Comment
• Default is EA, allowing both element names and attributes; the restrict property can limit to attributes only.

Event-Driven Programming with AngularJS

• Event-driven programming models interactions as dialogs, where events control the program flow.
• Event listeners monitor for events and trigger event handlers (callback functions).
• AngularJS is suitable for developing frontend frameworks over RESTful APIs, focusing on data presentation and two-way data binding.
• It supports data integrity by ensuring real-time changes are reflected in the underlying data store.

JavaScript HTML DOM Elements

• DOM elements provide a means to interact with HTML elements on a webpage by various selectors (ID, tag name, class name, CSS selectors).
• JavaScript allows access to these elements to manipulate content dynamically.

Changing HTML with JavaScript

• The Document Object Model (DOM) lets JavaScript modify HTML elements.
• document.write() can write directly to the HTML output stream.
• The innerHTML property is used to change the content of HTML elements.

UI Logic and Controllers

• MVC (Model-View-Controller) architecture is employed for web applications.
• The Controller manages user requests, working with the Model and View:
  • Model: Maintains application data, responds to view requests, and processes controller instructions.
  • View: Displays data from the Model to users and allows data modifications.
  • Controller: Handles user operations and passes appropriate views with model data.

Introduction to AngularJS

• AngularJS is a structured JavaScript framework designed for dynamic single-page applications.
• It leverages HTML for functionality, promoting efficient data binding and dependency management to reduce code length and complexity.

JavaScript Overview

• JavaScript is used for client-side scripting, allowing for interactive and dynamic web pages.
• The changeText(id) function changes the inner HTML of an element to display "Ooops!" when called.

Programming Structures in JavaScript

• Key programming structures include:
  • Conditional statements (if...else, nested structures, ternary operators)
  • Selection statements (switch)
  • Functions with parameters
  • Input popups for user interaction

Conditional Statements

• Conditional statements enable different actions based on specific conditions.
• Examples include:
  • if...else, used to execute different code blocks depending on whether a condition is true.
  • Nested structures that allow for multiple conditions to be checked.
  • Ternary operators as a shorthand for if...else.

Introduction to jQuery

• jQuery simplifies JavaScript by providing an easier syntax for manipulating HTML elements.
• Basic jQuery syntax: $(selector).action()
• Examples of common actions:
  • $(this).hide(): Hides the current element.
  • $("p").hide(): Hides all paragraph elements.

jQuery Library References

• jQuery can be downloaded and included in projects or used via a CDN (Content Delivery Network).
• Google and Microsoft host jQuery libraries, offering easy access to the latest versions.

Web Technologies and Servers

• ISPs connect users to the internet through various technologies like DSL, cable modem, and wireless.
• Apache HTTP Server is an open-source web server compatible with both Windows and Unix/Linux.
• IIS (Internet Information Services) is a web server designed for Windows, requiring manual installation.
• To publish websites on IIS, the home page should be named Default.htm or Default.asp and placed in the wwwroot directory.

Semantic HTML Elements

• Semantic elements describe their meaning clearly, aiding both browsers and developers.
• Examples of semantic elements:
  • `` for self-contained content.
  • `` for related content.
  • and for document structure.
• HTML5 introduced new semantic elements to define parts of a web page more effectively.

New Input Types and Attributes

• New input types in HTML5 include:
  • Color, date, email, search, and tel.
• New input attributes include:
  • required, placeholder, max, and min.

WordPress Basics

• Adding new pages to navigation menus in WordPress requires updating the menu in the "Appearance" section.
• Widgets can be managed in the sidebar through the "Appearance -> Widgets" section.
• Plugins extend WordPress functionalities and can be installed via the "Plugins" menu.

Content Migration

• Content migration planning should begin early in the project to avoid delays and extra costs.
• Key steps include:
  • Allocating adequate budget and resources for a successful migration.
  • Integrating planning into the initial content strategy phase and ensuring it extends into the design phase.

JavaScript Procedures

• Assigning the sum of variables x and y to ans is initialized with var x = 10; and var y = 20;.
• The result is calculated with ans = x + y; and displayed using document.getElementById("demo").innerHTML.

Variables and Data Types

• JavaScript supports multiple data types:
  • Number: Includes integers and floats, e.g., var length = 16;.
  • String: Groupings of characters, e.g., "hello world".
  • Object: More complex data types represented as var x = {firstName: "Saman", lastName: "Withanage"};.
  • Boolean: Represents true/false values; used in conditional statements, e.g., var raining = false;.

Conditional Statements

• IF Statement: Executes code block if the condition is true. Example: if (hour < 18) { greeting = "Good day"; }.
• ELSE Statement: Executes code block if the IF condition is false.
• ELSE IF Statement: Allows testing multiple conditions in succession.
• SWITCH Statement: Manages multiple potential execution blocks based on a variable's value.

jQuery Basics

• jQuery simplifies DOM manipulation and event handling, allowing efficient code with less complexity.
• Selecting Elements: Use $("XX") to select elements and manipulate them.
• Adding Classes: Method .addClass() is used to add CSS classes to elements.
• Document Ready: $(document).ready(function() {...}); ensures code runs after the DOM is fully loaded.

AJAX (Asynchronous JavaScript and XML)

• AJAX enables communication with a server without reloading a web page, enhancing user experience.
• Key steps in AJAX workflow:
  • User action triggers JavaScript to create a request via XMLHttpRequest.
  • An HTTP request is sent, and the server processes it.
  • Server communicates with a database to retrieve data.
  • Data is returned to the client, typically as JSON or XML.
  • JavaScript updates the web page dynamically without full reloads.

Validation and Error Handling

• Form validation rules are commonly defined to ensure user input correctness.
• Example validation: first name and last name are required fields; the email field requires a valid email format.
• Custom error messages can guide users to correct their input before submission.

Hosting and Maintenance

• Understanding web server systems and frameworks is crucial for hosting and maintaining websites.
• Effective web applications rely on both front-end (HTML, JavaScript, CSS) and back-end interactions with databases or server-side languages.

Summary of Key Concepts

• Mastering JavaScript and jQuery facilitates the development of interactive web applications.
• AJAX is a powerful tool for building responsive, asynchronous web interfaces.
• Form validation enhances user experience by ensuring proper data entry.

JavaScript Functionality

• changeText(id) modifies the inner HTML of the specified element to "Ooops!".
• Client-side scripting allows for dynamic interactions on web pages using JavaScript.
• Key programming concepts include functions, conditional statements, and passing parameters.

Learning Outcomes

• Ability to implement conditional and selection statements in programs.
• Understanding how to create and maintain web content on remote hosting services.

Conditional Statements

• Essential for executing different actions based on varying conditions.
• Implements constructs such as:
  • IF ... ELSE statements
  • Nested structures for advanced logic
  • Ternary operators for concise conditional evaluations
• Introduces multiple selection options using SWITCH statement.

Web Hosting Overview

• Web hosting provides storage for websites to be accessible online.
• Websites require hosting on connected computers known as servers.
• Hosting services allow users to view web pages by entering a domain name into a browser.

Server Technologies

• Utilizes various server software and protocols like Apache and IIS.
• Domain name registration and management of web servers are fundamental for hosting.
• includes maintenance features like file permissions, indexing, and remote login methods.

Single Page Applications (SPAs)

• SPAs enhance user experience by avoiding full page reloads during navigation.
• Benefits include lower server response payloads and reduced network traffic.
• Popular JavaScript frameworks for building SPAs include Angular, React, and Vue.js.

AngularJS Framework

• AngularJS supports building rich Internet applications using MVC architecture.
• Features include automatic handling of browser compatibility and open-source licensing under Apache 2.0.

Advantages and Disadvantages of AngularJS

• Advantages:
  • Framework facilitates creation of SPAs.
  • Rich data binding enhances user experience.
  • Encourages unit testable code and component reuse.
• Disadvantages:
  • Security vulnerabilities.
  • Limited degradability.

AngularJS Features

• Expressions are utilized with double braces (e.g., {{ expression }}) to bind data dynamically.
• Directives, prefixed with ng-, extend HTML features for enhanced functionality in applications.
  • ng-app initializes the application.
  • ng-init sets initial values.
  • ng-model binds form controls to application data, ensuring type validation and status tracking.

HTML5 Enhancements

• Introduces new attributes and elements to improve web forms and semantic markup.
• Features include persistent local storage, WebSockets for communication, and the Canvas API for drawing.
• Geolocation capability allows users to share their physical location when accessing applications.
• Drag-and-drop functionalities improve user interaction on web pages.