20.1. Embedding a Flex Application in HTML

By now, you should be aware that Flex applications get compiled to .swf files. When you deploy a Flex application to the Web, you must place the .swf file for the Flex application on the web server. At a minimum, this one file is always required. However, in almost all cases you will need to provide at least one additional file: an HTML file that embeds the .swf. Although it is possible for users to access an .swf file directly in a web browser, such an approach is inadvisable. Keep in mind that when users access a Flex application in a browser, you will still want the browser to display basic information such as a title, information that only an HTML page can provide. Furthermore, by using an HTML page, it is possible to do much more with a Flex application than if the user was accessing the application’s .swf file directly in the browser. For example, using an HTML page you can utilize JavaScript. And by embedding a Flex application in HTML, you can place the application alongside other non-Flex content. Not only that, but by using JavaScript and HTML, you can detect whether the user even has Flash Player installed. Therefore, embedding Flex applications in HTML is a fundamental skill for creating Flex applications. In the next few sections, we will look at various ways in which you can embed Flex content in HTML pages.