by Eric A. Meyer
First edition, published May 2000.
(See the catalog page for this book.)
Search the text of Cascading Style Sheets: The Definitive Guide.
Web-based applications are similar to app servers, except for one thing: Web-based applications don't have client apps, instead they use web browsers on the client side. They generate their front ends using HTML, which is dynamically generated by the web-based app. In the Java world, Servlets are best suited for this job.
Web-based apps might themselves rely on another app server to gather information that is presented on the client web browser. Also, you can write Servlets that get information from remote or local databases, XML document repositories and even other Servlets. One good use for web-based apps is to be a wrapper around an app server, so that you can allow your customers to access at least part of the services offered by your app server via a simple web browser. So web-based apps allow you to integrate many components including app servers, and provide access to this information over the web via a simple web browser.
Web-based apps are very deployable, since they don't require special Java VMs to be installed on the client side, or any other special plug ins, if the creator of the web-based app relies solely on HTML. Unfortunately, this can restrict the level of service that can be offered by a web-based app when compared to the functionality offered by custom clients of an app server, but they are a good compromise when it comes to providing web-based access to your information. In fact, in a real world scenario, both a web-based app and app server may be used together, in order to provide your customers access to their information. In an Intranet setting, you might deploy the clients that come with the app server, and in an Internet setting it would be better to deploy a web-based app that sits on top of this app server, and gives your customers (relatively) limited access to their data over the web (via a simple web browser).
Copyright © 2002 O'Reilly & Associates. All rights reserved.effort of using the longer notation of attribute selectors? The reason to use attribute selectors is that the .class and #ID selectors apply only to HTML documents, or to any other document that uses a language that includes the concepts of class and ID. Other languages, such as those based on XML, might not honor these conventions, in which case you'll need to use the attribute selectors instead.
Not quite, no. In the old page, the navigation bar was separated slightly fromthe main display, but ran right up against the sidebar, therebycreating a sort of inverted green "L" shape. We want tomake sure that this is still the case in the new setup. This is mosteasily accomplished by making sure that the division has no paddingor border set, and that it is guaranteed to be as wide as the tablecell in which it's found. Plus, we want the bar to have alittle bit of blank space after it, so we need a margin of zero oneverything but the bottom, where we just want a few pixels. So we add width of the DIV 'scontent, as illustrated in Figure 8-7.
Thus, if the width of the DIVis 30em , then the sum total of the content width,padding, borders, and margins of each paragraph will be30em. In Figure 8-7, the"blank" space around the paragraphs is actually theirmargins. (If the DIV had any padding, there would