Getting the signature of a function
To write the C++ code that invokes the f_mult function,
you need to obtain its method ID. The method ID is used to initialize
the PBCallInfo structure and to invoke the function. There are two
IPB_Session functions that return a method ID: GetMethodID,
which takes a signature, and FindMatchingFunction,
which takes a comma-separated list of arguments. You use the same
functions when you call PowerScript from the code in your extension;
see “Calling PowerScript from
an extension”.
If you want to use GetMethodID, you need
a signature. This function is simple enough that you do not need
a tool to obtain a signature—the signature is the string III,
which indicates that the function returns an integer and takes two integers
as arguments.
For more complicated functions, you can get the signature
from the System Tree or with the pbsig125 tool.
Getting a signature from the System Tree
To get the signature of f_mult in
the System Tree, expand nvo_mult,
right-click on the f_mult function,
and select Properties from the pop-up menu. The signature displays
in the Properties dialog box in the Signature text box:
Getting a signature using pbsig125
To get the signature of f_mult with pbsig125,
type the following at a command prompt:
|
1 |
pbsig125 d:pblsloadpbvm.pbl |
In the output of pbsig125, the comment
on the last line contains the signature to be passed as the method
ID argument to GetMethodID:
|
1 |
PB Object Name: loadpbvm<br> <br>PB Object Name: nvo_mult<br>   public function integer f_mult (integer arg1,<br>      integer arg2)<br>      /* III */ |
For more information about the pbsig125 tool
and the format of method signatures, see pbsig125.