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NAME

Attribute.pm - generates all get- and set-methods for new classes created by classgen.

VERSION

3.03

SYNOPSIS

Within classgen called as:

        use Attribute;                  # work with object Attribute
        my $attr = Attribute->new();    # derive a new Attribute instance $attr

Let Ex.pm be a generated class, with internal variables $var, %entry and @list:

        use Ex.pm;                      # use generated class
        my $ex=Ex->new();               # creating a new object
        $ex->set_var('this is a test'); # setting instance variable $var
        $ex->set_h_entry( 12, twelve ); # like $entry{12}='twelve'
        $ex->set_h_entry( 60, sixty );  # 
        $ex->set_l_list( 3, -100 );     # like $list[3]=-100;
        $x=$ex->get_var();              # like $x=$var;
        $x=$ex->get_h_entry(12);
        @keys=$ex->get_keys_h_entry();  # get all keys of internal %entry
etc.

DESCRIPTION

It is good OOP-style to access and manipulate instance variables of a class NEVER by a direct call, but via appropriate methods. You should always follow this concept to avoid problems when inheriting from your object oriented code.

classgen has been designed for exactly this purpose: To have all necessary methods available for all instance variables. Right from the start.

General syntax for generated methods

The methods name itself should uniquely identify the type of instance variable accessed or modified. So the general method convention is:

methodname_scalarname to work on a scalar instance
methodname_h_hashname to work on a hash instance
methodname_l_listname to work on a list instance

With this convention you will always know what to expect, e.g.:

        use Example;
        $ex = Example->new();
        ...
        print $ex->get_number;          # access instance variable $number
        print $ex->get_l_cities;        # access instance variable @cities
        print $ex->get_keys_h_country;  # get keys of inst.var. %country

For %hashes and @lists it is sometimes necessary to access the reference of the instance variable. Then use:

methodname_rh_hashname to find the reference of a %hash instance
methodname_rl_listname to find the reference of a @list instance

Some other methods deviate from these rules when purpose and involved type of instance variable are self evident. See below.

Generated methods for $scalars

For all $scalar instance variables in classgens control file Attribute.pm generates (the phrase 'scalar' is replaced by the actual name of the $scalar instance variable):

clear_scalar(): generated clear() method for $scalars
get_scalar(): generated accessor method for $scalars
set_scalar($value): generated manipulator for $scalars

Example: control file contains $var of class Example.

Attribute generates clear_var(), get_var() and set_var. Class Example can be used like:

        use Example;    # use object Example
        use strict;     # recommended

        my $ex = Example->new();        # creating a new Example instance
        $ex->clear_var();               # set $var in Example to undef
        $ex->set_var( "what a wonderful day" );

        print $ex->get_var();

Generated methods for %hashes

For all %hash instance variables in classgens control file Attribute.pm generates (the phrase 'hash' is replaced by the actual name of the %hash instance variable):

clear_h_hash(): generated clear() method for %hashes
delete_h_hash_at($key): deletes $key from internal %hash.
get_h_hash(): generated accessor to the %hash itself
get_h_hash_at($key): generated key-based accessor to %hash
get_keys_h_hash(): generated key-accessor for %hashes
get_rh_hash(): generated accessor to \%hashes
set_h_hash($key, $value): generated manipulator for %hashes

Generated methods for @lists

For all @list instance variables in classgens control file Attribute.pm generates (the phrase 'list' is replaced by the actual name of the @list instance variable):

clear_l_list(): generated clear() method for @lists
get_list_at($index): generated indexed-accessor for @lists
get_l_list(): generated list-accessor for @lists
get_rl_list(): generated accessor to \@lists
pop_list(): generated pop-accessor for @lists
push_list($value): generated push-manipulator for @lists
set_l_list($index, $value): generated manipulator method for @lists