CAF::Object

NAME

CAF::Object - provides basic methods for all CAF objects

SYNOPSIS

use parent qw(CAF::Object ...);
...
sub _initialize {
    ... initialize your package
    return SUCCESS; # Success
}

DESCRIPTION

CAF::Object is a base class which provides basic functionality to CAF objects.

All other CAF objects should inherit from it.

All CAF classes use this as their base class and inherit their class constructor new from here. Sub-classes should implement all their constructor initialisation in an _initialize method which is invoked from this base class new constructor. Sub-classes should NOT need to override the new class method.

The subclass _initialize method has to be implemented and has to return a boolean value indicating if the initialisation was succesful (e.g. use SUCCESS exported by CAF::Object). In particular, one should avoid to return the $self instance at the end of _initialize (e.g. to avoid troubles when the subclass overloads logic evaluation (which is also possible via overloading other methods such as stringification)).

Public methods

• new

Creates an empty hash and bless’es it as the new class instance. All arguments are then passed to a $self->_initialize(@_) call. When _initialize returns success, the NoAction attribute is set to the value of CAF::Object::NoAction if it didn’t exist after _initialize. If _initialize returns failure, an error is thrown and undef returned.

• noAction

Returns the NoAction flag value (boolean)

Private methods

• _initialize

This method must be overwritten in a derived class

• error, warn, info, verbose, debug, report, OK, event

Convenience methods to access the log/reporter instance that might be passed during initialisation and set to $self->{log}.

(When constructing classes via multiple inheritance, CAF::Reporter should precede CAF::Object if you want to use an absolute rather than a conditional logger).

• fail

Handle failures. Stores the error message in the fail attribute, logs it with verbose and returns undef.

To be used in subclasses that are not supposed to log/report any errors themself when a problem or failure occurs. In such classes, all failures should use return $self->fail("message");.

• update_env

Update the hashref $env with key/value from the ENV attribute hashref. (A undef value will remove the key.)

Returns the env hashref.

To be used as

# Setup local environment
local %ENV = %ENV;
$self->update_env(\%ENV);

Example:

# some method_1 that prepares a shared environment
sub method_1
{
    ...
    # Prepare enviroment modifications
    $self->{ENV}->{PATH} = "/some/new/path:$ENV{PATH}";
    ...
}


sub do_something
{
   ...
   # Setup local environment
   local %ENV = %ENV;
   $self->update_env(\%ENV);

   # everything in the remainder of the method runs in modified environment
   # is limited to the scope of this method due to 'local'
   ...
}