Server-side Authoring
Spin is the only complete authoring tool that has the ability to author server-side programs (servlets) that run on web servers.For creating simple web pages that change infrequently, HTML is fine. But to create more dynamic content — content that updates automatically, is interactive, or accesses databases and other resources — you need something more powerful. And until now, more powerful has meant programming, usually CGI programming.
How would you like something that is more powerful than CGI programming, actually runs faster than CGI programming (so you can handle more hits on your web site), but is simple enough so that it can be used by anyone, including businesspeople, designers, and other nonprogrammers? You'd probably say something like that sounds too good to be true!
We challenge you to try Spin and see for yourself.
Advantages
Spin servlets have a large number of advantages over conventional server-side CGI programs.Portability
Spin servlets run on practically every server platform, whether it be Windows, Linux, Solaris, or even Macintosh. They will run on any web server (from Apache to Zeus) either natively or with a simple add-on.Capability
Spin servlets are tightly integrated with the web server, which allows Spin servlets to work closely with the server in ways that simply are not possible with CGI scripts. And because the integration with the server is done through a well defined interface, these capabilities are portable to any server, unlike server-specific CGI extensions, which are nonportable and tend to be dangerous and error prone.Speed
Spin servlets are compiled, so they run faster than CGI scripts written in interpreted languages like Perl. Servlets have an even more significant advantage. Servlets run as threads, rather than as separate processes, so invoking a servlet is usually hundreds of times faster than invoking a CGI script (even if that CGI script is written in a compiled language, like C). This significantly affects the number of hits per second that can be handled by a web server, so Spin can help you avoid having to buy a more expensive server when your business takes off. (Note that there are some web servers that allow you to run CGI scripts in the same process as the server, but this is nonportable, dangerous, and insecure.)Safety
Spin servlets are far safer than CGI scripts written in languages like C, C++, and Perl. This means they are far less likely to crash your server. Even if a servlet encounters an unexpected error, it can be restarted by the server without affecting either the server itself or any other servlets.Persistence
Conventional CGI scripts are stateless. Each time they are invoked, they start fresh with no memory of anything that has happened before. All state must be explicitly stored outside the CGI script, in files or in a database. This does not make it easy to create web sites where you are trying to have an ongoing interactive dialog with the user, such as an ecommerce application.Spin servlets have multiple levels of persistent state: per user, per servlet instance, per all servlet instances, or global.
Flexible HTML
A Spin servlet can be invoked through a URL, from an HTML form in a web page, or from a special Zat HTML tag. The servlet runs and generates HTML that is sent back to the web browser.With Spin, you have a choice as to how to generate the HTML that is sent back to the web browser. You can generate a complete web page from within Spin, for the ultimate in flexibility and dynamic coding, or you can use web pages generated by any HTML authoring tool, and insert active content where you need it. With Spin, you will not lose your investment in existing HTML web pages.
Overcome Browser Incompatibilities
Incompatibilities between different browsers is a web site designer's nightmare. Spin can actually detect which browser invoked the servlet, and send the appropriate HTML codes for that browser. This capability is completely customizable by the web page author.Components
Spin comes with a large set of components that are useful for writing server-side programs, including components for generating HTML, a visual tool for accessing databases, and components for sending email. Soon there will be even more components, including components that support ecommerce, business-to-business enterprise, chat rooms, web cams, intelligent counters, and more.Because Spin is based on components, you can reuse components that your write, or share them with others in your organization. For example, you can build servlets that handle navigation, and then share them with everyone in your organization, so your web sites have a consistent navigation paradigm.
Customizability
The most significant feature of Spin is that it makes it easier to take a complete solution and customize it to your individual needs. For example, a generic ecommerce solution written in Spin could be customized to the needs of an individual business, or modified as needs evolve over time.Debugging
Spin comes with an integrated web application server — a complete web server that can serve both Spin servlets and regular HTML pages. This allows you to test and debug your server-side programs with ease. You can even set breakpoints, single step, examine variables. With Spin, you can even make changes while your server-side program is running. Spin has better debugging facilities for server-side programs than most programming tools, but it's not a programming tool, it is an authoring tool that makes it much easier to build, customize, integrate, and maintain your server-side programs.
