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You also have to move any associated image files to the same directory that your installation of the WAS keeps static HTML files.
Keep in mind that you don’t have to use the Oracle webserver software for this to work, but it helps. You do need the Developer/2000 and Developer/2000 Server software.
Note:
The Developer/2000 Java applet requires version 1.1.2 of Java, which most browsers available at the time of this writing don’t support. To address this, Oracle ships an Applet Viewer that supports Java 1.3, and that works with the Developer/2000 Java applet.
Caution:
When designing Forms that will be used on the Web, keep the following in mind:
- • Timers (created with the CREATE_TIMER built-in procedure) are not allowed; the WHEN-TIMER-EXPIRED trigger will not work.
- • Any graphic objects that are referenced by the form, such as icons in a toolbar, for example, must conform to Web standards. In other words, you can use GIF images and JPG images, but not ICO files. Any image files that are used must be stored in the server in the same directory as the static HTML files.
- • You can’t use ActiveX, OLE, or VBX.
- • The mouse event triggers WHEN-MOUSE-MOVE, WHEN-MOUSE-LEAVE, and WHEN-MOUSE-ENTER don’t work.
- • The Autoskip item property doesn’t work.
- • The built-in procedure Set_Window_Property cannot minimize or maximize windows. And there is no MDI support in Web-world.
- • The built-in procedure Get_Item_Property cannot get object handles.
- • Because the form is actually executing on the server, the Host command, ORA_FFI, and user exit output display on the server, not the client—in other words, not in the browser.
- • Java doesn’t support combo boxes, so it shows them as pop lists instead.
Reports Builder 3.0 (known as Reports Designer in version 2.5), will deploy reports in either HTML or Adobe Acrobat PDF across the Web. You can schedule jobs to run at predetermined specific times, creating output files that remain on the Web server waiting to be downloaded. You can also set up the Reports Server, together with either the Reports Web Cartridge or the Web CGI, and allow users to execute reports on demand, dynamically creating output in either HTML or Adobe Acrobat PDF file format and sending output to the invoking client browser.
This is yet another truly amazing technology. Existing reports, written in Reports Designer 2.5, can be compiled in Reports Builder 3.0 and be immediately Web-enabled.
The Reports Server does not require the WAS. It can be run through a Web server CGI. But the Reports Server runs significantly faster when combined with the WAS and the Reports Web Cartridge, which provides native integration. Once up and running, the Reports Web Cartridge is always available, while the CGI interface starts and stops the executable with every invocation.
Note:
The Portable Document File (PDF) format, from Adobe Corporation, has be-come the de facto standard for distributing publication quality document files across the Internet to any platform. Anyone who downloads a PDF document must use the Adobe Acrobat Reader in order to read the document. The Reader is a free Web browser plug-in, is widely available, and runs on most platforms. Some browsers are starting to bundle it with their product.The reason PDF is so popular: It allows you to create the sort of complex documents that are normally published at great expense. They can be distributed easily as email attachments or in whatever manner possible, since they are platform-independent. PDF files can include hyperlinks, security options, and other features. The Adobe Corporation estimates that over a quarter of a million Web sites are already using PDF in one form or another. The IRS distributes their tax forms in PDF format. Many companies distribute their corporate annual reports in PDF format. Oracle distributes some of its online documentation in PDF.
The Reports Builder, when publishing in PDF format, can incorporate graphic images, including photographs, specific fonts and detailed formatting instructions. The output will appear and print exactly, not approximately, as I’ve described the HTML approach to file distribution, but precisely as originally created.
The combination of the Graphics Server and any Web browser (the “Graphics Client”) empowers developers to create graphic images that are driven by data from the database, and are deployed across the Web. These graphics can be integrated with Forms and Reports as desired.
Requests to the Graphics Server begin when the client is presented with an HTML file that contains hyperlinks that they can use to make a request for a graphic image. When the client makes the request, it is sent through the WAS, which forwards it to the Graphics Server. The Graphics Server generates the image and stores it in a file on the server. It also creates an HTML file that contains a tag to display the image file, and the Graphics Server sends the HTML file as output back to the client. The client (Web browser) receives the HTML file, displays it, and, according to the tag, incorporates the server-stored image file in the browser display.
This allows the Graphics Server to dynamically generate graphic images and deliver them to a standard Web browser.
Oracle’s Designer/2000 includes a Web server Generator that will take basic modules defined in the Designer/2000 repository and generate Web-enabled applications. The output is in the form of PL/SQL packages, intended for use with the PL/SQL Cartridge, described earlier. Each package contains a set of PL/SQL procedures that will, when invoked, present a series of Web pages for users to query data, display the results, and view details of their query. Designer/2000’s module preferences influence the way Designer generates the code, controlling the formatting and performance of the finished module.
If you already have an existing application in one of the many languages supported by Designer/2000, you can reverse engineer (in versions prior to 2.0), or “recover” (in version 2.0), the application into Designer’s repository, and then generate that application via Web server Generator to create a Web-enabled application.
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