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Hash::DefHash(3pm) User Contributed Perl Documentation Hash::DefHash(3pm)

NAME

Hash::DefHash - Manipulate defhash

VERSION

This document describes version 0.072 of Hash::DefHash (from Perl distribution Hash-DefHash), released on 2021-07-21.

SYNOPSIS

 use Hash::DefHash; # imports defhash()
 # create a new defhash object, die when hash is invalid defhash
 $dh = Hash::DefHash->new;                        # creates an empty defhash
 $dh = Hash::DefHash->new({a=>1});                # use the hashref
 $dh = Hash::DefHash->new({"contains space"=>1}); # dies!
 # defhash() is a synonym for Hash::DefHash->new().
 $dh = defhash({foo=>1});
 # return the original hash
 $hash = $dh->hash;
 # list properties
 @props = $dh->props;
 # list property names, values, and attributes, will return ($prop => $attrs,
 # ...). Property values will be put in $attrs with key "". For example:
 %content = DefHash::Hash->new({p1=>1, "p1.a"=>2, p2=>3})->contents;
 # => (p1 => {""=>1, a=>2}, p2=>3)
 # get property value, will die if property does not exist
 $propval = $dh->prop($prop);
 # like prop(), but will return undef if property does not exist
 $propval = $dh->get_prop($prop);
 # check whether property exists
 say "exists" if $dh->prop_exists($prop);
 # add a new property, will die if property already exists
 $dh->add_prop($prop, $propval);
 # add new property, or set value for existing property
 $oldpropval = $dh->set_prop($prop, $propval);
 # delete property, noop if property already does not exist. set $delattrs to
 # true to delete all property's attributes.
 $oldpropval = $dh->del_prop($prop, $delattrs);
 # delete all properties, set $delattrs to true to delete all properties's
 # attributes too.
 $dh->del_all_props($delattrs);
 # get property's attributes. to list defhash attributes, set $prop to undef or
 # ""
 %attrs = $dh->attrs($prop);
 # get attribute value, will die if attribute does not exist
 $attrval = $dh->attr($prop, $attr);
 # like attr(), but will return undef if attribute does not exist
 $attrval = $dh->get_attr($prop, $attr);
 # check whether an attribute exists
 @attrs = $dh->attr_exists($prop, $attr);
 # add attribute to a property, will die if attribute already exists
 $dh->add_attr($prop, $attr, $attrval);
 # add attribute to a property, or set value of existing attribute
 $oldatrrval = $dh->set_attr($prop, $attr, $attrval);
 # delete property's attribute, noop if attribute already does not exist
 $oldattrval = $dh->del_attr($prop, $attr, $attrval);
 # delete all attributes of a property
 $dh->del_all_attrs($prop);
 # get predefined properties
 say $dh->v;            # shortcut for $dh->get_prop('v')
 say $dh->default_lang; # shortcut for $dh->get_prop('default_lang')
 say $dh->name;         # shortcut for $dh->get_prop('name')
 say $dh->summary;      # shortcut for $dh->get_prop('summary')
 say $dh->description;  # shortcut for $dh->get_prop('description')
 say $dh->tags;         # shortcut for $dh->get_prop('tags')
 # get value in alternate languages
 $propval = $dh->get_prop_lang($prop, $lang);
 # get value in all available languages, result is a hash mapping lang => val
 %vals = $dh->get_prop_all_langs($prop);
 # set value for alternative language
 $oldpropval = $dh->set_prop_lang($prop, $lang, $propval);

CONTRIBUTOR

Steven Haryanto <sharyanto@cpan.org>

FUNCTIONS

defhash([ $hash ]) => OBJ

Shortcut for "Hash::DefHash->new($hash)". As a bonus, can also detect if $hash is already a defhash and returns it immediately instead of wrapping it again. Exported by default.

METHODS

new

Usage:

 $dh = Hash::DefHash->new([ $hash ],[ %opts ]);

Constructor. Create a new Hash::DefHash object, which is a thin OO skin over the regular Perl hash. If $hash is not specified, a new anonymous hash is created.

Internally, the object contains a hash reference which contains reference to the hash ("bless({hash=>$orig_hash, ...}, 'Hash::DefHash')"). It does not create a copy of the hash or bless the hash directly. Be careful not to assume that the two are the same!

Will check the keys of hash for invalid properties/attributes and will die if one is found, e.g..

 $dh = Hash::DefHash->new({"contains space" => 1}); # dies!

Known options:

  • check => BOOL (default: 1)

    Whether to check that hash is a valid defhash. Will die if hash turns out to contain invalid keys/values.

  • parent => HASH/DEFHASH_OBJ

    Set defhash's parent. Default language ("default_lang") will follow parent's if unset in the current hash.

hash

Usage:

 $hashref = $dh->hash;

Return the original hashref.

check

Usage:

 $dh->check;

contents

Usage:

 my %contents = $dh->contents;

default_lang

Usage:

 $default_lang = $dh->default_lang;

props

Usage:

 @props = $dh->props;

Return list of properties. Will ignore properties that begin with underscore, e.g.:

 $dh = defhash({a=>1, _b=>2});
 $dh->props;

prop

Usage:

 $val = $dh->prop($prop [ , \%opts ]);

Get property value, will die if property does not exist.

Known options:

  • die

    Bool. Default true. Whether to die when requested property is not found.

  • alt

    Hashref.

  • mark_different_lang

    Bool. Default false. If set to true, then when a requested property is found but differs (only) in the language it will be returned but with a mark. For example, with this defhash:

     {name=>"Chair", "name.alt.lang.id_ID"=>"Kursi"}

    then:

     $dh->prop("name", {lang=>"fr_FR"});

    will die. But:

     $dh->prop("name", {lang=>"fr_FR", mark_different_lang=>1});

    will return:

     "{en_US Chair}"

    or:

     "{id_ID Kursi}"

get_prop

Usage:

 my $val = $dh->get_prop($prop [ , \%opts ]);

Like "prop"(), but will return undef if property does not exist.

prop_exists

Usage:

 $exists = $dh->prop_exists;

add_prop

set_prop

del_prop

del_all_props

attrs

attr

get_attr

attr_exists

add_attr

set_attr

del_attr

del_all_attrs

defhash_v

v

name

summary

description

tags

get_prop_lang

Usage:

 my $val = $dh->get_prop_lang($prop, $lang [ , \%opts ]);

This is just a special case for:

 $dh->prop($prop, {alt=>{lang=>$lang}, mark_different_lang=>1, %opts});

get_prop_all_langs

set_prop_lang

HOMEPAGE

Please visit the project's homepage at <https://metacpan.org/release/Hash-DefHash>.

SOURCE

Source repository is at <https://github.com/perlancar/perl-Hash-DefHash>.

BUGS

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

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

DefHash specification

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2021, 2020, 2018, 2016, 2015, 2014, 2012 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.

2021-09-29 perl v5.32.1