Libero gives you the freedom you get to choose the language
that suits your purpose. The way I add support for a particular
language is to write a new schema file. This is a kind of
script that tells Libero how to generate code for that
particular language. Inevitably, the solution I choose for a
language tends to vary. For example, the C schema generates a
couple of include files to hold the generated code. The UNIX
shell schemas in contrast take a source 'module' file and
generate the final script (which you don't work on directly).
This section documents the special aspects of each language
(ie. schema). Some aspects that apply to all languages:
- All the schemas separate the generated code from the
hand-written code. This means either a strict division into
hand-written files and generated files, or some sleight-of-hand
to get a similar result. The mechanism varies from language to
language since I use the mechanisms that each language offers
(if any). You should understand which files you get when you
work in a particular language.
- Most languages provide some form of function or subroutine.
I define one such for each module in the dialog, and you are
free to define your own 'private' functions in the code. Libero
provides the facility to detect unused ('idle') modules, but for
this the syntax for the module functions must be different to
that for your private functions. (Otherwise Libero can't tell
the difference, and issues loads of incorrect warning messages.)
In a few languages I did not find an acceptable way of making
the distinction, so the -idle options is disabled. In the
remaining languages you must take care to follow the recommended
syntax for your private functions.
- The generated code provides a number of public data items
and functions. These have the same name in each language, as
far as possible. Reserved names start with '_LR_' or something
similar. Never use or refer to these names.
All schemas should support these names, which change syntax
according to the -style option:
- xxxx_event - defined for each event in the dialog,
where 'xxxx' is the name used in the dialog. Use these event
names whenever you need to set the value of the_next_event.
- the_next_event - the event for the next state. Set
this event in one of the action modules, before entering a new
- terminate_event - when you assign this to
the_next_event, the state machine halts. Normally you will do
this in the terminate_the_program module.
- exception_raised - if you set this to TRUE, the
dialog engine stops executing the current action list, and goes
into exception handling. Exceptions are described later.
- the_exception_event - before you raise an
exception, set this to the event you want to use as exception
event. This event must be defined in the current state you are
in, or in the Defaults state.
- initialise_the_program - this standard module is
called when the dialog engine starts; here you can access and
check parameters, and set a suitable next event like ok_event.
- get_external_event - this standard module is called
when the dialog needs an event, i.e. when none of the action
modules put anything in the_next_event.
- raise_exception - this standard function sets
exception_raised and places the specified event into
These schemas were contributed by Libero users, and are not
documented in detail here. You will need to read the schemas and
try them out to see how they work.
- The Oracle PL/SQL Language
PL/SQL is a scripting language used in the Oracle database
system. The PL/SQL schema was written by Claude Philippo and
Xavier Vermaut of Sema Group Belgium, and was kindly contributed
by Sema Group Belgium.
- The PHP Language
PHP is an Open Source scripting language used for web development.
system. The PHP schema was written and kindly contributed by