HTML5 APPLICATIONS DEVELOPMENT MANUAL (2016)

4 - Packaging and the Runtime Environment

Application packaging is the process of bundling an application and its resources into an archive format for distribution and deployment.

The App Container

• When a Web app executes, it does so in a contained environment

- An app container is a separate memory space

• The purpose of an app container is to prevent apps from corrupting the operating system

Permissions are grouped into permission sets, and every assembly is assigned a set. The .NET Framework defines some standard permission sets such as FullTrust (implies all permissions) and Execution (permission to access the CPU only).

Each user account is assigned a level of access (credentials). They can be set to use Windows Authentication, database authentication, no authentication, or custom authentication.

The Windows Runtime environment is the foundation of the Windows 8 operating system and provides functionality to Metro-style apps.

When you launch an app, it’s considered to be in a runtime environment (RTE). An RTE is where users run the app and developers test it. In Windows, this environment is called Windows Runtime (WinRT).

The WinRT works with C#, C++, Visual Basic, and JavaScript. You can build Metro style apps with the WinRT and Windows Library for JavaScript APIs. An application programming interface (API) is simply a list of instructions letting a program communicate with another program. In a Web app, an API enables a Web browser or a Web server to communicate with other programs. There are hundreds of APIs available for many different uses.

The Document Object Model (DOM) is an important API to keep in mind. The DOM is designed for HTML and Extensible Markup Language (XML), and allows programs and scripts to update content, structure, and styles on the fly - essentially anything in an HTML or XML file can be modified. The DOM is neither HTML nor JavaScript, but it ties them together.