NAME
    Data::Clean::JSON - Clean data so it is safe to output to JSON

VERSION
    This document describes version 0.17 of Data::Clean::JSON (from Perl
    distribution Data-Clean-JSON), released on 2014-11-07.

SYNOPSIS
     use Data::Clean::JSON;
     my $cleanser = Data::Clean::JSON->get_cleanser;
     my $data     = { code=>sub {}, re=>qr/abc/i };

     my $cleaned;

     # modifies data in-place
     $cleaned = $cleanser->clean_in_place($data);

     # ditto, but deep clone first, return
     $cleaned = $cleanser->clone_and_clean($data);

     # now output it
     use JSON;
     print encode_json($cleaned); # prints '{"code":"CODE","re":"(?^i:abc)"}'

DESCRIPTION
    This class cleans data from anything that might be problematic when
    encoding to JSON. This includes coderefs, globs, and so on.

    Data that has been cleaned will probably not be convertible back to the
    original, due to information loss (for example, coderefs converted to
    string "CODE").

    The design goals are good performance, good defaults, and just enough
    flexibility. The original use-case is for returning JSON response in
    HTTP API service.

    This module is significantly faster than modules like Data::Rmap or
    Data::Visitor::Callback because with something like Data::Rmap you
    repeatedly invoke callback for each data item. This module, on the other
    hand, generates a cleanser code using eval(), using native Perl for()
    loops.

    If "LOG_CLEANSER_CODE" environment is set to true, the generated
    cleanser code will be logged using Log::Any at trace level. You can see
    it, e.g. using Log::Any::App:

     % LOG_CLEANSER_CODE=1 TRACE=1 perl -MLog::Any::App -MData::Clean::JSON \
       -e'$c=Data::Clean::JSON->new; ...'

METHODS
  CLASS->get_cleanser => $obj
    Return a singleton instance, with default options. Use "new()" if you
    want to customize options.

  CLASS->new(%opts) => $obj
    Create a new instance. For list of known options, see Data::Clean::Base.
    Data::Clean::JSON sets some defaults.

        DateTime  => [call_method => 'epoch']
        Regexp    => ['stringify']
        SCALAR    => ['deref_scalar']
        -ref      => ['replace_with_ref']
        -circular => ['clone']
        -obj      => ['unbless']

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

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

ENVIRONMENT
    LOG_CLEANSER_CODE

FAQ
  Why clone/modify? Why not directly output JSON?
    So that the data can be used for other stuffs, like outputting to YAML,
    etc.

  Why is it slow?
    If you use "new()" instead of "get_cleanser()", make sure that you do
    not construct the Data::Clean::JSON object repeatedly, as the
    constructor generates the cleanser code first using eval(). A short
    benchmark (run on my slow Atom netbook):

     % bench -MData::Clean::JSON -b'$c=Data::Clean::JSON->new' \
         'Data::Clean::JSON->new->clone_and_clean([1..100])' \
         '$c->clone_and_clean([1..100])'
     Benchmarking sub { Data::Clean::JSON->new->clean_in_place([1..100]) }, sub { $c->clean_in_place([1..100]) } ...
     a: 302 calls (291.3/s), 1.037s (3.433ms/call)
     b: 7043 calls (4996/s), 1.410s (0.200ms/call)
     Fastest is b (17.15x a)

    Second, you can turn off some checks if you are sure you will not be
    getting bad data. For example, if you know that your input will not
    contain circular references, you can turn off circular detection:

     $cleanser = Data::Clean::JSON->new(-circular => 0);

    Benchmark:

     $ perl -MData::Clean::JSON -MBench -E '
       $data = [[1],[2],[3],[4],[5]];
       bench {
           circ   => sub { state $c = Data::Clean::JSON->new;               $c->clone_and_clean($data) },
           nocirc => sub { state $c = Data::Clean::JSON->new(-circular=>0); $c->clone_and_clean($data) }
       }, -1'
     circ: 9456 calls (9425/s), 1.003s (0.106ms/call)
     nocirc: 13161 calls (12885/s), 1.021s (0.0776ms/call)
     Fastest is nocirc (1.367x circ)

    The less number of checks you do, the faster the cleansing process will
    be.

  Why am I getting 'Not a CODE reference at lib/Data/Clean/Base.pm line xxx'?
    [2013-08-07 ] This error message is from Data::Clone::clone() when it is
    cloning an object. If you are cleaning objects, instead of using
    clone_and_clean(), try using clean_in_place(). Or, clone your data first
    using something else like Sereal.

SEE ALSO
    Data::Rmap

    Data::Visitor::Callback

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

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

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

    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.

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2014 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.

