NAME

    Object::HashBase - Build hash based classes.

SYNOPSIS

    A class:

        package My::Class;
        use strict;
        use warnings;
    
        # Generate 3 accessors
        use Object::HashBase qw/foo -bar ^baz/;
    
        # Chance to initialize defaults
        sub init {
            my $self = shift;    # No other args
            $self->{+FOO} ||= "foo";
            $self->{+BAR} ||= "bar";
            $self->{+BAZ} ||= "baz";
        }
    
        sub print {
            print join ", " => map { $self->{$_} } FOO, BAR, BAZ;
        }

    Subclass it

        package My::Subclass;
        use strict;
        use warnings;
    
        # Note, you should subclass before loading HashBase.
        use base 'My::Class';
        use Object::HashBase qw/bat/;
    
        sub init {
            my $self = shift;
    
            # We get the constants from the base class for free.
            $self->{+FOO} ||= 'SubFoo';
            $self->{+BAT} ||= 'bat';
    
            $self->SUPER::init();
        }

    use it:

        package main;
        use strict;
        use warnings;
        use My::Class;
    
        my $one = My::Class->new(foo => 'MyFoo', bar => 'MyBar');
    
        # Accessors!
        my $foo = $one->foo;    # 'MyFoo'
        my $bar = $one->bar;    # 'MyBar'
        my $baz = $one->baz;    # Defaulted to: 'baz'
    
        # Setters!
        $one->set_foo('A Foo');
    
        #'-bar' means read-only, so the setter will throw an exception (but is defined).
        $one->set_bar('A bar');
    
        # '^baz' means deprecated setter, this will warn about the setter being
        # deprecated.
        $one->set_baz('A Baz');
    
        $one->{+FOO} = 'xxx';

DESCRIPTION

    This package is used to generate classes based on hashrefs. Using this
    class will give you a new() method, as well as generating accessors you
    request. Generated accessors will be getters, set_ACCESSOR setters will
    also be generated for you. You also get constants for each accessor
    (all caps) which return the key into the hash for that accessor. Single
    inheritance is also supported.

INCLUDING IN YOUR DIST

    If you want to use HashBase, but do not want to depend on it, you can
    include it in your distribution.

        $ hashbase_inc.pl Prefix::For::Module

    This will create 2 files:

        lib/Prefix/For/Module/HashBase.pm
        t/HashBase.t

    You can then use the includes Prefix::For::Module::HashBase instead of
    Object::HashBase.

    You can re-run this script to regenerate the files, or upgrade them to
    newer versions.

    If the script was not installed, it can be found int he scripts/
    directory.

METHODS

 PROVIDED BY HASH BASE

    $it = $class->new(@VALUES)

      Create a new instance using key/value pairs.

      HashBase will not export new() if there is already a new() method in
      your packages inheritance chain.

      If you do not want this method you can define your own you just have
      to declare it before loading Object::HashBase.

          package My::Package;
      
          # predeclare new() so that HashBase does not give us one.
          sub new;
      
          use Object::HashBase qw/foo bar baz/;
      
          # Now we define our own new method.
          sub new { ... }

      This makes it so that HashBase sees that you have your own new()
      method. Alternatively you can define the method before loading
      HashBase instead of just declaring it, but that scatters your use
      statements.

 HOOKS

    $self->init()

      This gives you the chance to set some default values to your fields.
      The only argument is $self with its indexes already set from the
      constructor.

ACCESSORS

    To generate accessors you list them when using the module:

        use Object::HashBase qw/foo/;

    This will generate the following subs in your namespace:

    foo()

      Getter, used to get the value of the foo field.

    set_foo()

      Setter, used to set the value of the foo field.

    FOO()

      Constant, returns the field foo's key into the class hashref.
      Subclasses will also get this function as a constant, not simply a
      method, that means it is copied into the subclass namespace.

      The main reason for using these constants is to help avoid spelling
      mistakes and similar typos. It will not help you if you forget to
      prefix the '+' though.

SUBCLASSING

    You can subclass an existing HashBase class.

        use base 'Another::HashBase::Class';
        use Object::HashBase qw/foo bar baz/;

    The base class is added to @ISA for you, and all constants from base
    classes are added to subclasses automatically.

SOURCE

    The source code repository for HashBase can be found at
    http://github.com/Test-More/HashBase/.

MAINTAINERS

    Chad Granum <exodist@cpan.org>

AUTHORS

    Chad Granum <exodist@cpan.org>

COPYRIGHT

    Copyright 2016 Chad Granum <exodist@cpan.org>.

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

    See http://dev.perl.org/licenses/

