NAME
    Data::Clean - Clean data structure

VERSION
    This document describes version 0.500 of Data::Clean (from Perl
    distribution Data-Clean), released on 2018-10-09.

SYNOPSIS
     use Data::Clean;

     my $cleanser = Data::Clean->new(
         # specify how to deal with specific classes
         'DateTime'     => [call_method => 'epoch'], # replace object with its epoch
         'Time::Moment' => [call_method => 'epoch'], # replace object with its epoch
         'Regexp'       => ['stringify'], # replace $obj with "$obj"

         # specify how to deal with all scalar refs
         SCALAR         => ['deref_scalar'], # replace \1 with 1

         # specify how to deal with circular reference
         -circular      => ['clone'],

         # specify how to deal with all other kinds of objects
         -obj           => ['unbless'],
     );

     # to get cleansed data
     my $cleansed_data = $cleanser->clone_and_clean($data);

     # to replace original data with cleansed one
     $cleanser->clean_in_place($data);

DESCRIPTION
    This class can be used to process a data structure by replacing some
    forms of data items with other forms. One of the main uses is to clean
    "unsafe" data, e.g. clean a data structure so it can be encoded to JSON
    (see Data::Clean::JSON, which is a thin wrapper over this class).

    As can be seen from the example, you specify a list of transformations
    to be done, and then this class will generate an appropriate Perl code
    to do the cleansing. This class is faster than the other ways of
    processing, e.g. Data::Rmap (see Bencher::Scenarios::DataCleansing for
    some benchmarks).

METHODS
  new(%opts) => $obj
    Create a new instance.

    Options specify what to do with certain category of data. Option keys
    are either reference types (like "HASH", "ARRAY", "SCALAR") or class
    names (like "Foo::Bar"), or "-obj" (to match all kinds of objects,
    a.k.a. blessed references), "-circular" (to match circular references),
    "-ref" (to refer to any kind of references, used to process references
    not handled by other options). Option values are arrayrefs, the first
    element of the array is command name, to specify what to do with the
    reference/class. The rest are command arguments.

    Note that arrayrefs and hashrefs are always walked into, so it's not
    trapped by "-ref".

    Default for %opts: "-ref => 'stringify'".

    Option keys that start with "!" are special:

    *   !recurse_obj (bool)

        Can be set to true to to recurse into objects if they are hash- or
        array-based. By default objects are not recursed into. Note that if
        you enable this option, object options (like "Foo::Bar" or "-obj")
        won't work for hash- and array-based objects because they will be
        recursed instead.

    *   !clone_func (str)

        Set fully qualified name of clone function to use. The default is to
        use "Sereal::Dclone::dclone" if available, or fallback to
        "Clone::PP::clone".

    Available commands:

    *   ['stringify']

        This will stringify a reference like "{}" to something like
        "HASH(0x135f998)".

    *   ['replace_with_ref']

        This will replace a reference like "{}" with "HASH".

    *   ['replace_with_str', STR]

        This will replace a reference like "{}" with *STR*.

    *   ['call_method' => STR]

        This will call a method named *STR* and use its return as the
        replacement. For example: "DateTime->from_epoch(epoch=>1000)" when
        processed with "[call_method => 'epoch']" will become 1000.

    *   ['call_func', STR]

        This will call a function named *STR* with value as argument and use
        its return as the replacement.

    *   ['one_or_zero']

        This will perform "$val ? 1:0".

    *   ['deref_scalar']

        This will replace a scalar reference like \1 with 1.

    *   ['unbless']

        This will perform unblessing using
        Function::Fallback::CoreOrPP::unbless(). Should be done only for
        objects ("-obj").

    *   ['code', STR]

        This will replace with *STR* treated as Perl code.

    *   ['clone', INT]

        This command is useful if you have circular references and want to
        expand/copy them. For example:

         my $def_opts = { opt1 => 'default', opt2 => 0 };
         my $users    = { alice => $def_opts, bob => $def_opts, charlie => $def_opts };

        $users contains three references to the same data structure. With
        the default behaviour of "-circular => [replace_with_str =>
        'CIRCULAR']" the cleaned data structure will be:

         { alice   => { opt1 => 'default', opt2 => 0 },
           bob     => 'CIRCULAR',
           charlie => 'CIRCULAR' }

        But with "-circular => ['clone']" option, the data structure will be
        cleaned to become (the $def_opts is cloned):

         { alice   => { opt1 => 'default', opt2 => 0 },
           bob     => { opt1 => 'default', opt2 => 0 },
           charlie => { opt1 => 'default', opt2 => 0 }, }

        The command argument specifies the number of references to clone as
        a limit (the default is 50), since a cyclical structure can lead to
        infinite cloning. Above this limit, the circular references will be
        replaced with a string "CIRCULAR". For example:

         my $a = [1]; push @$a, $a;

        With "-circular => ['clone', 2]" the data will be cleaned as:

         [1, [1, [1, "CIRCULAR"]]]

        With "-circular => ['clone', 3]" the data will be cleaned as:

         [1, [1, [1, [1, "CIRCULAR"]]]]

  $obj->clean_in_place($data) => $cleaned
    Clean $data. Modify data in-place.

  $obj->clone_and_clean($data) => $cleaned
    Clean $data. Clone $data first.

ENVIRONMENT
    *   LOG_CLEANSER_CODE => BOOL (default: 0)

        Can be enabled if you want to see the generated cleanser code. It is
        logged at level "trace".

    *   LINENUM => BOOL (default: 1)

        When logging cleanser code, whether to give line numbers.

HOMEPAGE
    Please visit the project's homepage at
    <https://metacpan.org/release/Data-Clean>.

SOURCE
    Source repository is at <https://github.com/perlancar/perl-Data-Clean>.

BUGS
    Please report any bugs or feature requests on the bugtracker website
    <https://rt.cpan.org/Public/Dist/Display.html?Name=Data-Clean>

    When submitting a bug or request, please include a test-file or a patch
    to an existing test-file that illustrates the bug or desired feature.

SEE ALSO
    Related modules: Data::Rmap, Hash::Sanitize, Data::Walk.

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2018, 2017, 2016 by perlancar@cpan.org.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

