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NAME

Params::Dry - Simple Global Params Management System which helps you to keep DRY principle

VERSION

version 1.20.03

SYNOPSIS

Fast start!

  • tdef/typedef - defines global types for variables

  • __@_ - starts parameter fetching

  • rq/param_rq - get required parameter

  • op/param_op - get optional parameter

  • no_more - marks that all parametrs has been fetched (required only in some cases)

Example:

    package ParamsTest;

    use strict;
    use warnings;

    our $VERSION = 1.0;

    #=------------------------------------------------------------------------( use, constants )

    use Params::Dry qw(:short);

    #=------------------------------------------------------------------------( typedef definitions )

    # --- how to define types?  - its Easy :)
    typedef 'name', 'String[20]';

    typedef 'subname', 'name';  # even Easier :)
    typedef 'subname_or_id', 'name|Int[5]';  # uuuuuf.. yes it is possible :)

    #=------------------------------------------------------------------------( functions )


    sub new {

        # --- using parameters :)

        my $self = __@_;    # inteligent __ function will return $self on '$self->new' call or undef on 'new' call

        # --- geting parameters data

        #+ required parameter name (in 'name' (autodetected) type (see typedefs above) with no default value)
        my $p_name          = rq 'name'; # this is using default type for required parameter name without default value

        #+ optional parameter second_name (in 'name' type (see typedefs above) with default value 'unknown')
        my $p_second_name   = op 'second_name', 'name', 'unknown'; # this is using name typee for optional parameter name with default value set to 'unknown'

        #+ optional parameter details (in build-in 'String' type  with default value '')
        my $p_details       = op 'details', 'String', ''; # unlimited string for optional parameter details

        return bless {
                    name        => $p_name,
                    second_name => $p_second_name,
                    details     => $p_details,
                }, 'ParamsTest';
    }

    my $lucja = new(name => 'Lucja', second_name => 'Marta');

More you can find in examples

DESCRIPTION

Understanding the main concepts

First. If you can use any function as in natural languague - you will use and understand it even after few months.

Second. Your lazy life will be easy, and you will reduce a lot of errors if you will have guarancy that your parameter in whole project means the same ( ex. when you see 'client' you know that it is always String[32] ).

Third. You want to set the type in one and only in one place.

Yes, DRY principle in its pure form!

So all your dreams you can now find in this module.

That's all. Easy to use. Easy to manage. Easy to understand.

EXPORT

  • :shorten - imports: 'op', 'rq', '_', 'tdef' and 'DEFAULT_TYPE' constant

  • :short - imports: 'op', 'rq', '__', 'typedef', 'no_more' and 'DEFAULT_TYPE' constant

  • :long - imports: 'param_op', 'param_rq', '__', 'typedef', 'no_more' and 'DEFAULT_TYPE' constant

CONSTANTS AND VARIABLES

  • TRUE - set to 1

  • FALSE - set to 0

  • OK - set to TRUE (1)

  • NO - set to FALSE (0)

  • DEFAULT_TYPE - to mark that you want to use default type

  • $Debug - if set to TRUE (default: FALSE) will show more debug

SUBROUTINES/METHODS

__ - snail operator

Start getting the parameters. Used on the begin of the function

    sub pleple {
        my $self = __@_;

RETURN: first param if was called like $obj->pleple(%params) or undef on pleple(%params) call

rq or param_rq - required parameter

Check if required parameter exists, if yes check if its valid, if not, report error

rq in param name [in param type, [default value]]

    sub pleple {
        my $self = __@_;

        my $p_param1 = rq 'param1'; # assuming that param1 is defined before by typedef
        my $p_param2 = rq 'param2', 'String';
        my $p_param3 = rq 'param3', 'String', 'Default value';
        my $p_param4 = rq 'param4', DEFAULT_TYPE, 'Default value'; # assuming that param4 is defined before but wanted to give default value

    ...

    pleple(param1 => 'test', param2 => 'bleble');

RETURN: parameter value

op or param_op - optional parameter

Check if required parameter exists, if yes check it, if not return undef

op in param name [in param type, [default value]]

see above

    my $p_param1 = op 'param1'; # .. see above

RETURN: parameter value

no_more - marks that no more parameters will be readed

It can be useful in some cases, for example whan default value of the param is the function call and this function is using parameters as well.

The function is getting from internal stack previous parameters

Example.

    sub get_val {
        my $self = __@_;

        my $p_name = rq 'name';

        no_more; # to give back old parameters

    }

    sub main {
        my $self = __@_;

        my $p_nick = rq 'nick', 'String', $self->get_val(name => 'somename');

    }

It is good practice to use no_more at the end of geting parameters Also the strict parameter checking implementation is planed in next releases (so using no_more you will be able to die if apear more parameters that was fetched - to avoid misspelings)

tdef or typedef - defines global types for variables

You see parameter in 'customer' type, and you know, that it mean always String[40]. In whole project. This is a big advantage of using predefined types. (btw. the typedef if you are not trying to redefine already existing type)

Ok, your project is growing and you need to change customer type to String[60].

Oh no! You have to accept customer by name or id. So just set String[60]|Int.

Easy. One type definition, one place to be changed. That is how it helps you to keep DRY principle in your code.

typedef type name, type definition;

    # ---   name and definition  - its Easy :)
    typedef 'name', 'String[40]';

    typedef 'subname', 'name';  # can be even Easier :)

    typedef 'subname_or_id', 'name|Int[5]';  # uuuuuf :)

RETURN: name of the already defined type

BUILD IN TYPES

  • String - can be used with parameters (like: String[20]) which mean max 20 chars string

  • Int - can be used with parameters (like: Int[3]) which mean max 3 chars int not counting signs, shortcut of Number::Int

  • Float - number with decimal part, shortcut of Number::Float

  • Bool - boolean value (can be 0 or 1), shortcut of Number::Bool

  • Object - check if is an object. Optional parameter extend check of exact object checking ex. Object[DBI::db]

  • Defined - pass if value is defined

  • Value - pass if it is not a reference

  • Ref - any reference, Optional parameter defines type of the reference

  • Scalar - shortcut of Ref[Scalar] or Ref::Scalar

  • Array - shortcut of Ref[Array] or Ref::Array

  • Hash - shortcut of Ref[Hash] or Ref::Hash

  • Code - shortcut of Ref[Code] or Ref::Code

  • Regexp - shortcut of Ref[Regexp] or Ref::Regexp

RESERVED/USED SUBTYPES

Subtypes/Namespaces which are already used/reserved

  • Params::Dry::Types - main types

  • Params::Dry::Types::Number - number types

  • Params::Dry::Types::String - string types

  • Params::Dry::Types::Ref - ref types

  • Params::Dry::Types::Object - reserved for extended object types

Extending internal types

You can always write your module to check parameters. Please use always subnamespace of Params::Dry::Types

You will to your check function param value and list of the type parameters

Example.

    package Params::Dry::Types::Super;

    use Params::Dry::Types qw(:const);

    sub String {
        Params::Dry::Types::String(@_) and $_[0] =~ /Super/ and return PASS;
         return FAIL;
    }

    ...

    package main;

    sub test {
        my $self = __@_;

        my $p_super_name = rq 'super_name', 'Super::String'; # that's all folks!

        ...
    }

ADDITIONAL INFORMATION

1. I didn't wrote here any special extensions (callbacks, ordered parameter list, evals etc). Params::Dry module has to be fast.

If there will be any extension in future. It will be in separate module.

2. Ordered parameters list or named parameter list? Named parameter list. For sure.

Majority of the time you are spending on READING code, not writing it. So for sure named parameter list is better.

AUTHOR

Pawel Guspiel (neo77), <neo at cpan.org>

BUGS

Please report any bugs or feature requests to bug-params at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Params-Dry. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc Params::Dry
    perldoc Params::Dry::Types

You can also look for information at:

ACKNOWLEDGEMENTS

LICENSE AND COPYRIGHT

Copyright 2013 Pawel Guspiel (neo77).

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

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