The wrapper is responsible for embedding the Flex application's SWF file in a web page, such as an HTML, ASP, JSP, or Adobe ColdFusion page. In addition, you use the logic in the wrapper to enable deep linking and Express Install, and to ensure that users both with and without JavaScript enabled in their browsers can access your Flex applications. You can also use the wrapper to pass flashVars variables into your Flex applications and to use the ExternalInterface API. These topics are described in Communicating with the Wrapper.

There are several ways to create a wrapper:

• Write a custom wrapper using the instructions in Creating a simple wrapper.
• Export and customize an HTML wrapper from Flex Builder. For more information, see About the Flex Builder wrapper.
• Use the templates provided in the /templates directory. For more information, see About the HTML templates.
• Use the html-wrapper Flex Ant task. For more information, see Using the html-wrapper task.
• Generate the HTML wrapper with the Flex module for Apache and IIS. For more information, see Customizing the template.

Adobe® Flex® Builder™and the Flex module for Apache and IIS generate a wrapper that embeds your Flex application. The Flex Builder wrapper include support for Express Install and deep linking by default, although you can disable these features or configure them to your specifications. Deep linking lets users navigate the history of their interactions within the Flex application using the browser's Forward and Back buttons, and it lets users read and write to the browser's address bar. Express Install ensures that your users have a good upgrade experience if their Players require an update. The wrapper created by the Flex module for Apache and IIS does not support Express Install or deep linking.

The mxmlc command-line compiler does not generate a wrapper. You must write it manually using the instructions in Creating a simple wrapper. You can start out with a simple wrapper that just embeds your Flex application. You can then add deep linking and Express Install support to your wrapper.