—package
JSON::Path;
$JSON::Path::VERSION
=
'1.0.6'
;
use
strict;
use
warnings;
# VERSION
our
$AUTHORITY
=
'cpan:POPEFELIX'
;
our
$Safe
= 1;
use
Carp;
use
LV ();
sub
jpath {
my
(
$object
,
$expression
) =
@_
;
my
@return
= __PACKAGE__->new(
$expression
)->
values
(
$object
);
}
sub
jpath1 : lvalue {
my
(
$object
,
$expression
) =
@_
;
__PACKAGE__->new(
$expression
)->value(
$object
);
}
sub
jpath_map (&$$) {
my
(
$coderef
,
$object
,
$expression
) =
@_
;
return
__PACKAGE__->new(
$expression
)->
map
(
$object
,
$coderef
);
}
sub
new {
my
(
$class
,
$expression
) =
@_
;
return
$expression
if
blessed(
$expression
) &&
$expression
->isa(__PACKAGE__);
return
bless
\
$expression
,
$class
;
}
sub
to_string {
my
(
$self
) =
@_
;
return
$$self
;
}
sub
paths {
my
(
$self
,
$object
) =
@_
;
my
@paths
= JSON::Path::Evaluator::evaluate_jsonpath(
$object
,
"$self"
,
want_path
=> 1);
return
@paths
;
}
sub
get {
my
(
$self
,
$object
) =
@_
;
my
@values
=
$self
->
values
(
$object
);
return
wantarray
?
@values
:
$values
[0];
}
sub
set {
my
(
$self
,
$object
,
$value
,
$limit
) =
@_
;
if
( !
ref
$object
) {
# warn if not called internally. If called internally (i.e. from value()) we will already have warned.
my
@c
=
caller
(0);
if
(
$c
[1] !~ /JSON\/Path\.pm$/ ) {
carp
qq{Useless attempt to set a value on a non-reference}
;
}
}
my
$count
= 0;
my
@refs
= JSON::Path::Evaluator::evaluate_jsonpath(
$object
,
"$self"
,
want_ref
=> 1 );
for
my
$ref
(
@refs
) {
${
$ref
} =
$value
;
++
$count
;
last
if
$limit
&& (
$count
>=
$limit
);
}
return
$count
;
}
sub
value : lvalue {
my
(
$self
,
$object
) =
@_
;
LV::lvalue(
get
=>
sub
{
my
(
$value
) =
$self
->get(
$object
);
return
$value
;
},
set
=>
sub
{
my
$value
=
shift
;
# do some caller() magic to warn at the right place
if
( !
ref
$object
) {
my
@c
=
caller
(2);
my
(
$filename
,
$line
) =
@c
[ 1, 2 ];
warn
qq{Useless attempt to set a value on a non-reference at $filename line $line\n}
;
}
$self
->set(
$object
,
$value
, 1 );
},
);
}
sub
values
{
my
(
$self
,
$object
) =
@_
;
croak
q{non-safe evaluation, died}
if
"$self"
=~ /\?\(/ &&
$JSON::Path::Safe
;
return
JSON::Path::Evaluator::evaluate_jsonpath(
$object
,
"$self"
,
script_engine
=>
'perl'
);
}
sub
map
{
my
(
$self
,
$object
,
$coderef
) =
@_
;
my
$count
;
foreach
my
$path
(
$self
->paths(
$object
) ) {
my
(
$ref
) = JSON::Path::Evaluator::evaluate_jsonpath(
$object
,
$path
,
want_ref
=> 1 );
++
$count
;
my
$value
=
do
{
no
warnings
'numeric'
;
local
$_
= ${
$ref
};
local
$. =
$path
;
scalar
$coderef
->();
};
${
$ref
} =
$value
;
}
return
$count
;
}
1;
__END__
=pod
=encoding utf-8
=head1 NAME
JSON::Path
=head1 VERSION
version 1.0.6
=head1 SYNOPSIS
my $data = {
"store" => {
"book" => [
{ "category" => "reference",
"author" => "Nigel Rees",
"title" => "Sayings of the Century",
"price" => 8.95,
},
{ "category" => "fiction",
"author" => "Evelyn Waugh",
"title" => "Sword of Honour",
"price" => 12.99,
},
{ "category" => "fiction",
"author" => "Herman Melville",
"title" => "Moby Dick",
"isbn" => "0-553-21311-3",
"price" => 8.99,
},
{ "category" => "fiction",
"author" => "J. R. R. Tolkien",
"title" => "The Lord of the Rings",
"isbn" => "0-395-19395-8",
"price" => 22.99,
},
],
"bicycle" => [
{ "color" => "red",
"price" => 19.95,
},
],
},
};
use JSON::Path 'jpath_map';
# All books in the store
my $jpath = JSON::Path->new('$.store.book[*]');
my @books = $jpath->values($data);
# The author of the last (by order) book
my $jpath = JSON::Path->new('$..book[-1:].author');
my $tolkien = $jpath->value($data);
# Convert all authors to uppercase
jpath_map { uc $_ } $data, '$.store.book[*].author';
=head1 DESCRIPTION
This module implements JSONPath, an XPath-like language for searching
JSON-like structures.
JSONPath is described at L<http://goessner.net/articles/JsonPath/>.
=head2 Constructor
=over 4
=item C<< JSON::Path->new($string) >>
Given a JSONPath expression C<$string>, returns a C<JSON::Path> object.
=back
=head2 Methods
=over 4
=item C<< values($object) >>
Evaluates the JSONPath expression against an object. The object $object
can be either a nested Perl hashref/arrayref structure, or a JSON string
capable of being decoded by JSON::MaybeXS::decode_json.
Returns a list of structures from within $object which match against the
JSONPath expression. In scalar context, returns the number of matches.
=item C<< value($object) >>
Like C<values>, but returns just the first value. This method is an lvalue
sub, which means you can assign to it:
my $person = { name => "Robert" };
my $path = JSON::Path->new('$.name');
$path->value($person) = "Bob";
TAKE NOTE! This will create keys in $object. E.G.:
my $obj = { foo => 'bar' };
my $path = JSON::Path->new('$.baz');
$path->value($obj) = 'bak'; # $obj->{baz} is created and set to 'bak';
=item C<< paths($object) >>
As per C<values> but instead of returning structures which match the
expression, returns canonical JSONPaths that point towards those structures.
=item C<< get($object) >>
In list context, identical to C<< values >>, but in scalar context returns
the first result.
=item C<< set($object, $value, $limit) >>
Alters C<< $object >>, setting the paths to C<< $value >>. If set, then
C<< $limit >> limits the number of changes made.
TAKE NOTE! This will create keys in $object. E.G.:
my $obj = { foo => 'bar' };
my $path = JSON::Path->new('$.baz');
$path->set($obj, 'bak'); # $obj->{baz} is created and set to 'bak'
Returns the number of changes made.
=item C<< map($object, $coderef) >>
Conceptually similar to Perl's C<map> keyword. Executes the coderef
(in scalar context!) for each match of the path within the object,
and sets a new value from the coderef's return value. Within the
coderef, C<< $_ >> may be used to access the old value, and C<< $. >>
may be used to access the curent canonical JSONPath.
=item C<< to_string >>
Returns the original JSONPath expression as a string.
This method is usually not needed, as the JSON::Path should automatically
stringify itself as appropriate. i.e. the following works:
my $jpath = JSON::Path->new('$.store.book[*].author');
print "I'm looking for: " . $jpath . "\n";
=back
=head2 Functions
The following functions are available for export, but are not exported
by default:
=over
=item C<< jpath($object, $path_string) >>
Shortcut for C<< JSON::Path->new($path_string)->values($object) >>.
=item C<< jpath1($object, $path_string) >>
Shortcut for C<< JSON::Path->new($path_string)->value($object) >>.
Like C<value>, it can be used as an lvalue.
=item C<< jpath_map { CODE } $object, $path_string >>
Shortcut for C<< JSON::Path->new($path_string)->map($object, $code) >>.
=back
=head1 NAME
JSON::Path - search nested hashref/arrayref structures using JSONPath
=head1 PERL SPECIFICS
JSONPath is intended as a cross-programming-language method of
searching nested object structures. There are however, some things
you need to think about when using JSONPath in Perl...
=head2 JSONPath Embedded Perl Expressions
JSONPath expressions may contain subexpressions that are evaluated
using the native host language. e.g.
$..book[?($_->{author} =~ /tolkien/i)]
The stuff between "?(" and ")" is a Perl expression that must return
a boolean, used to filter results. As arbitrary Perl may be used, this
is clearly quite dangerous unless used in a controlled environment.
Thus, it's disabled by default. To enable, set:
$JSON::Path::Safe = 0;
There are some differences between the JSONPath spec and this
implementation.
=over 4
=item * JSONPath uses a variable '$' to refer to the root node.
This is not a legal variable name in Perl, so '$root' is used
instead.
=item * JSONPath uses a variable '@' to refer to the current node.
This is not a legal variable name in Perl, so '$_' is used
instead.
=back
=head2 Blessed Objects
Blessed objects are generally treated as atomic values; JSON::Path
will not follow paths inside them. The exception to this rule are blessed
objects where:
Scalar::Util::blessed($object)
&& $object->can('typeof')
&& $object->typeof =~ /^(ARRAY|HASH)$/
which are treated as an unblessed arrayref or hashref appropriately.
=head1 BUGS
Please report any bugs to L<http://rt.cpan.org/>.
=head1 SEE ALSO
Specification: L<http://goessner.net/articles/JsonPath/>.
Implementations in PHP, Javascript and C#:
Jayway JsonPath:
Related modules: L<JSON>, L<JSON::JOM>, L<JSON::T>, L<JSON::GRDDL>,
L<JSON::Hyper>, L<JSON::Schema>.
Similar functionality: L<Data::Path>, L<Data::DPath>, L<Data::SPath>,
L<Hash::Path>, L<Path::Resolver::Resolver::Hash>, L<Data::Nested>,
L<Data::Hierarchy>... yes, the idea's not especially new. What's different
is that JSON::Path uses a vaguely standardised syntax with implementations
in at least three other programming languages.
=head1 AUTHOR
Aurelia Peters L<https://github.com/popefelix>
=head1 CONTRIBUTORS
Toby Inkster https://github.com/tobyink
Szymon Nieznański https://github.com/s-nez
Heiko Jansen https://github.com/heikojansen
Mitsuhiro Nakamura https://github.com/mnacamura
David Escribano García https://github.com/DavidEGx
Thomas Helsel https://github.com/thelsel
Patrick Cronin https://github.com/PatrickCronin
James Bowery https://github.com/jabowery
Slaven Rezić https://github.com/eserte
Max Laager https://github.com/mlaagerc2c
Elvin Aslanov https://github.com/rwp0
James Raspass https://github.com/JRaspass
Bernhard Schmalhofer https://github.com/bschmalhofer
=head1 COPYRIGHT AND LICENCE
Copyright 2007 Stefan Goessner.
Copyright 2010-2013 Toby Inkster.
Copyright 2021-2024 Aurelia Peters
This module is tri-licensed. It is available under the X11 (a.k.a. MIT)
licence; you can also redistribute it and/or modify it under the same
terms as Perl itself.
=head2 a.k.a. "The MIT Licence"
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=head1 AUTHOR
Aurelia Peters <popefelix@gmail.com>
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2024 by Aurelia Peters.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut