Net.Data applications for the HTTP Server

This topic provides a general overview of Net.Data®.

Important: Information for this topic supports the latest PTF levels for HTTP Server for i5/OS . It is recommended that you install the latest PTFs to upgrade to the latest level of the HTTP Server for i5/OS. Some of the topics documented here are not available prior to this update. See http://www.ibm.com/servers/eserver/iseries/software/http/services/service.htm Link outside Information Center for more information.

Net.Data is a server-side scripting engine that allows you to easily create dynamic documents using live data from a variety of sources such as relational and non-relational database management systems (DBMSs), including DB2® databases that can be accessed through DRDA®, files, and native applications written in programming languages such as RPG, Cobol, Java™, C, C++, and REXX.

Net.Data operates on scripts called macros, which contains a series of statements that are defined by the Net.Data macro language. These statements can include standard HTML (or XML, etc.) and language environment-specific statements (for example, SQL statements) as well as macro directives. These statements act as instructions to the Net.Data macro processor, telling it how to construct the dynamic page. Net.Data interprets the statements to create dynamic Web pages with customized content based on input from the user, the current state of your databases, other data sources, existing business logic, and other factors that you design into your macro. The dynamic page that is generated can be rendered in a variety of formats. For example, HTML for browser clients, XML for browser and application clients, wireless markup language (WML) for wireless clients, and Excel for application clients.

The Net.Data macro processor communicates with the HTTP Server through its CGI-BIN interface. The server uses TCP/IP to connect to the Internet. Like other CGI-BIN programs, Net.Data is typically stored in the server’s CGI-BIN directory. Net.Data is accessed when a URL received by the server refers to the Net.Data macro processor executable, DB2WWW, in the CGI-BIN directory.

When a URL is received by the server that refers to the Net.Data macro processor program, the server starts an instance of the macro processor. It then passes essential information, including the name of the requested macro and the section of the macro to use. The macro processor then:
  1. Reads and parses through the macro.
  2. Interprets all the macro statements.
  3. Dynamically builds the page.
  4. Sends the data to the HTTP server by writing to stdout.

The macro writer has complete control over what format the generated data is in (for example: HTML or XML). The macro processor imposes no restrictions. After the text is passed back to the server, the macro processor ends. The resulting text is passed to the client (or browser) where the user interacts with it. Further requests from this user or any other user will result in the whole process just described taking place again.

For more detailed information about Net.Data, including how to configure Net.Data and how to write Net.Data macros and language environments, see the Net.Data for iSeries™ home page Link outside Information Center.

Parent topic: Programming