NAME

JSON::Pointer - A Perl implementation of JSON Pointer (RFC6901)

VERSION

This document describes JSON::Pointer version 0.06.

SYNOPSIS

use JSON::Pointer;

my $obj = {
  foo => 1,
  bar => [ { qux => "hello" }, 3 ],
  baz => { boo => [ 1, 3, 5, 7 ] }
};

JSON::Pointer->get($obj, "/foo");       ### $obj->{foo}
JSON::Pointer->get($obj, "/bar/0");     ### $obj->{bar}[0]
JSON::Pointer->get($obj, "/bar/0/qux"); ### $obj->{bar}[0]{qux}
JSON::Pointer->get($obj, "/bar/1");     ### $obj->{bar}[1]
JSON::Pointer->get($obj, "/baz/boo/2"); ### $obj->{baz}{boo}[2]

DESCRIPTION

This library is implemented JSON Pointer (http://tools.ietf.org/html/rfc6901) and some useful operator from JSON Patch (http://tools.ietf.org/html/rfc6902).

JSON Pointer is available to identify a specified value in JSON document, and it is simillar to XPath. Please read the both of specifications for details.

METHODS

get($document :HashRef/ArrayRef/Scalar, $pointer :Str, $strict :Int) :Scalar

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to be presented by JSON format.

• $pointer :Str

  JSON Pointer string to identify specified value in the document.

• $strict :Int

  Strict mode. When this value equals true value, this method may throw exception on error. When this value equals false value, this method return undef value on error.

Get specified value identified by $pointer from $document. For example,

use JSON::Pointer;
print JSON::Pointer->get({ foo => 1, bar => { "qux" => "hello" } }, "/bar/qux"); ### hello

contains($document :HashRef/ArrayRef/Scalar, $pointer :Str) :Int

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to present by JSON format.

• $pointer :Str

  JSON Pointer string to identify specified value in the document.

Return which the target location identified by $pointer exists or not in the $document.

use JSON::Pointer;

my $document = { foo => 1 };
if (JSON::Pointer->contains($document, "/foo")) {
  print "/foo exists";
}

add($document :HashRef/ArrayRef/Scalar, $pointer :Str, $value :HashRef/ArrayRef/Scalar) :HashRef/ArrayRef/Scalar

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to be presented by JSON format.

• $pointer :Str

  JSON Pointer string to identify specified value in the document.

• $value :HashRef/ArrayRef/Scalar

  The perl data structure that is able to be presented by JSON format.

Add specified $value on target location identified by $pointer in the $document. For example,

use JSON::Pointer;

my $document = +{ foo => 1, };
my $value = +{ qux => "hello" };

my $patched_document = JSON::Pointer->add($document, "/bar", $value);
print $patched_document->{bar}{qux}; ### hello

remove($document, $pointer) :Array/Scalar

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to be presented by JSON format.

• $pointer :Str

  JSON Pointer string to identify specified value in the document.

Remove target location identified by $pointer in the $document.

use JSON::Pointer;

my $document = { foo => 1 };
my $patched_document = JSON::Pointer->remove($document, "/foo");
unless (exists $patched_document->{foo}) {
  print "removed /foo";
}

This method is contextial return value. When the return value of wantarray equals true, return $patched_document and $removed_value, or not return $patched_document only.

replace($document :HashRef/ArrayRef/Scalar, $pointer :Str, $value :HashRef/ArrayRef/Scalar) :Array/HashRef/ArrayRef/Scalar

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to be presented by JSON format.

• $pointer :Str

  JSON Pointer string to identify specified value in the document.

• $value :HashRef/ArrayRef/Scalar

  The perl data structure that is able to be presented by JSON format.

Replace the value of target location specified by $pointer to the $value in the $document.

use JSON::Pointer;

my $document = { foo => 1 };
my $patched_document = JSON::Pointer->replace($document, "/foo", 2);
print $patched_document->{foo}; ## 2

This method is contextial return value. When the return value of wantarray equals true, return $patched_document and $replaced_value, or not return $patched_document only.

set($document :HashRef/ArrayRef/Scalar, $pointer :Str, $value :HashRef/ArrayRef/Scalar) :Array/HashRef/ArrayRef/Scalar

This method is alias of replace method.

copy($document :HashRef/ArrayRef/Scalar, $from_pointer :Str, $to_pointer :Str) :HashRef/ArrayRef/Scalar

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to be presented by JSON format.

• $from_pointer :Str

  JSON Pointer string to identify specified value in the document.

• $to_pointer :Str

  JSON Pointer string to identify specified value in the document.

Copy the value identified by $from_pointer to target location identified by $to_pointer. For example,

use JSON::Pointer;

my $document = +{ foo => [ { qux => "hello" } ], bar => [ 1 ] };
my $patched_document = JSON::Pointer->copy($document, "/foo/0/qux", "/bar/-");
print $patched_document->{bar}[1]; ## hello

Note that "-" notation means next of last element in the array. In this example, "-" means 1.

move($document :HashRef/ArrayRef/Scalar, $from_pointer :Str, $to_pointer :Str) :HashRef/ArrayRef/Scalar

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to be presented by JSON format.

• $from_pointer :Str

  JSON Pointer string to identify specified value in the document.

• $to_pointer :Str

  JSON Pointer string to identify specified value in the document.

Move the value identified by $from_pointer to target location identified by $to_pointer. For example,

use JSON;
use JSON::Pointer;

my $document = +{ foo => [ { qux => "hello" } ], bar => [ 1 ] };
my $patched_document = JSON::Pointer->move($document, "/foo/0/qux", "/bar/-");
print encode_json($patched_document); ## {"bar":[1,"hello"],"foo":[{}]}

test($document :HashRef/ArrayRef/Scalar, $pointer :Str, $value :HashRef/ArrayRef/Scalar) :Int

• $document :HashRef/ArrayRef/Scalar

  Target perl data structure that is able to be presented by JSON format.

• $pointer :Str

  JSON Pointer string to identify specified value in the document.

• $value :HashRef/ArrayRef/Scalar

  The perl data structure that is able to be presented by JSON format.

Return which the value identified by $pointer equals $value or not in the $document. This method distinguish type of each values.

use JSON::Pointer;

my $document = { foo => 1 };

print JSON::Pointer->test($document, "/foo", 1); ### 1
print JSON::Pointer->test($document, "/foo", "1"); ### 0

traverse($document, $pointer, $opts) : JSON::Pointer::Context

This method is used as internal implementation only.

DEPENDENCIES

Perl 5.8.1 or later.

BUGS

All complex software has bugs lurking in it, and this module is no exception. If you find a bug please either email me, or add the bug to cpan-RT.

SEE ALSO

• perl

• Mojo::JSON::Pointer

  Many codes in this module is inspired by the module.

• http://tools.ietf.org/html/rfc6901

• http://tools.ietf.org/html/rfc6902

AUTHOR

Toru Yamaguchi

LICENSE AND COPYRIGHT

Copyright (c) 2013, Toru Yamaguchi. All rights reserved.

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