19.3.5 Steps to Create RDML Built-In Functions
1. Design the Built-In Function.
2. Allocate the next Unique number.
If this is a User Defined Built-In Function, this step is not compulsory, but if you do decide to take this step, use the next available number between -401 and -600.
If this is an Other Vendor Built-In Function then use the next available number in The LANSA Group allocated range (within the Other Vendor range of -601 to -999).
Once the number range is allocated by LANSA Pty Ltd then it would be necessary to reflect this into the DC@F47 & DC@F48 records for the OV RDML BIF(s) via DFU. Another possibility is to put in a dummy DC@F47 record that is one less than the start of your range, either before compiling the first OV RDML BIF the first time or removing the DC@F47/DC@F48 records for your already compiled OV RDML BIFs.
3. Give the Built-In Function a name. Use something that even a non-programmer would understand. Prefix your own (User Defined) BIFs with 'UD_' and Other Vendor BIFs with 'OV_' for easy identification as described in 19.3.2 RDML Naming Conventions.
4. Give the function a name. If the RDML BIF is to be distributed, this name must be as documented under naming conventions. If the BIF name is less than 7 characters and this is a User Defined BIF, then the function name could be the same as the BIF name. Refer to the 19.3.2 RDML Naming Conventions if necessary.
5. Complete a Built-In Function definition form. Use either the one that is described later in this manual, or one that you have designed yourself.
Note: This step is not compulsory but it is a good idea if this is your first Built-In Function. It is meant as an aid to translating your Built-In Function design into the RDML necessary to cause LANSA to define it for you. If this data is incorrect, then the Built-In Function may not work as expected.
6. Code your function. Use the BBRDMLBIF template supplied to assist with initial coding of the BIF definition, arguments and return values.
The application template called BBRDMLBIF will generate the function skeleton for an RDML Built-In Function. The RDML that is generated follows the recommendations in 19.3.7 RDML Built-In Function Tips and Techniques.