After defining a PL/SQL interface to a foreign function, you can invoke the foreign function using PL/SQL from Oracle Forms. To invoke the foreign function from PL/SQL, specify the PL/SQL package name followed by a dot and the PL/SQL function name. This example shows how to invoke the foreign functions Get_Image and Show_Image from the ImageLib PL/SQL package.
PROCEDURE display_image(keywrd IN OUT VARCHAR2) IS
img_ptr ORA_FFI.POINTERTYPE;
BEGIN
img_ptr := ImageLib.Get_Image(keywrd);
ImageLib.Show_Image(img_ptr,2);
END;
Invoking a foreign function from a PL/SQL interface passes process control to the foreign function. Upon completion of the foreign function, process control is returned to Oracle Forms.
Passing parameter values to a foreign function using PL/SQL
Returning a value from a foreign function using PL/SQL example