4 6 Automatic Data Exchange

LANSA Web Functions

4.6 Automatic Data Exchange

LANSA automatically handles all data interchange between WEBEVENT functions.

When a linked function is called from your WEBEVENT function, the following will automatically be exchanged:

  • all form variables
  • hidden fields
  • all browse list data.

It is very important that the browse list definitions must be identical in all respects in all called functions as well as the current function being executed. If you have more than one DEF_LIST command in your function, all the browse lists will be exchanged even though you are only displaying one of the browse lists in your function.

If you exceed the LANSA exchange list limit, you can turn on the Enable Extended Exchange flag in the Web Administrator. Once you have enabled this option, you will have to recompile your functions. The Enable Extended Exchange flag is on the Miscellaneous tab of the Configure Data/Application Server in the LANSA for the Web Administrator. LANSA for the Web Administrator will have been installed when you installed LANSA for the Web. Refer to the Exchange List item in the Summary of Platform Differences.

When you create WEBEVENT functions, you MUST NOT use commitment controls as each function is effectively a new job. This style of application does not cater for database cursors.

To understand how and when this data is purged, refer to 4.10 WEBEVENT Data and Function Timeout.