Understanding front calls
Front calls execute a native function on the front-end platform.
In your Genero program, use the ui.Interface.frontCall() class method to invoke
front-end functions. When calling a user function from programs, specify a module name and a
function name. Input and output parameters can be passed/returned in order to transmit/receive
values to/from the front-end. A typical example is an "open file" dialog window that allows you to
select a file from the front-end workstation file system.
Front calls can be specific to the platform or front-end technology. For example, it is not possible to perform a shellexec front call with the GBC front-end, when using the GAS.
A set of front-end functions is built-in by default in front-ends. However, it is possible to write your own functions in order to extend the front-end possibilities.