This section discusses the various flavours that are available to the CICS programmer; terminology is reviewed along with various implementations scenarios. The IBM's Websphere environment is introduced and a brief description of the required directive statements necessary to make it work with a CICS system will be presented.
When implementing the CICS/WEB interface, one must understand the concepts of TCP/IP ports and services; one must also distinguish between the facilities immediately supported by the CICS software and those that must be implemented using the TCP/IP Socket Interface. These things are discussed here plus a description of the new TCPIPSERVICE resource definition is presented.
At the heart of the Web presentation is the HyperText Markup Language, a script style language used to produce web pages. Although there are multiple tools that will shield the programmer from having expert level knowledge of this facility, it will be advantageous to know basic HTML. This section will discuss the main HTML tags such as body, table, table header (TH), table data (TD) and META. This chapter will also be used to introduce the Unix System Services environment and some the commands available from a TSO session such as OMVS, OEDIT, OGET and OPUT. The lab will be to define and test a web page that will be used later in the week.
What is required to implement this facility, the converter program DFHWBTTA, the CICS utility DFHBMSUP, the document template generation process using BMS maps as input, customization work required for these templates, their implementation in Unix HFS files. The lab will consist of taking a small CICS/3270 application and make it work on the web. This chapter is used to introduce the 3270-Bridge facility of CICS.
WEB Business Logic Interface (BLI)
Introduction of the Business Logic interface and its components. This model encourages the implementation of a 2-tier system: presentation and business. We will discuss how the CWS interfaces with BLI, the ENCODE and DECODE functions of the converter program which is responsible for the presentation logic, COMMAREA's layout used by the interface and, finally, the interaction between the BLI and the CWS analyser program.
A description of the environment is provided along with implementation strategies. Since this facility is using the CICS External Interface (EXCI), this facility is also fully explained. Finally, the mechanism used by Websphere to make this happens.
CICS WEB Support
In this section, the programmer will learn about writing web-aware CICS application programs. We will review the environment that is necessary to support this type of environment. We will also cover all the CICS commands necessary to manage document templates, how to extract information from these templates, how to move new data to these templates, how to send and receive data, extract HTTP header information and the DOCTEMPLATE resource definition. The lab will use the web page built earlier in the week to transmit a request to CICS and receive a response.
JAVA, IIOP and Security
Description of the support provided for Java programs, the interface to CORBA/IIOP and a description of the security environment will be presented.