This is an implementation of the JSON specification according to RFC 7159 http://www.ietf.org/rfc/rfc7159.txt .
The JSON generator generate UTF-8 character sequences by default. If an :ascii_only option with a true value is given, they escape all non-ASCII and control characters with \uXXXX escape sequences, and support UTF-16 surrogate pairs in order to be able to generate the whole range of unicode code points.
All strings, that are to be encoded as JSON strings, should be UTF-8 byte sequences on the Ruby side. To encode raw binary strings, that aren't UTF-8 encoded, please use the to_json_raw_object method of String (which produces an object, that contains a byte array) and decode the result on the receiving endpoint.
Install the gem and add to the application's Gemfile by executing:
$ bundle add json
If bundler is not being used to manage dependencies, install the gem by executing:
$ gem install json
To use JSON you can
require 'json'Now you can parse a JSON document into a ruby data structure by calling
JSON.parse(document)If you want to generate a JSON document from a ruby data structure call
JSON.generate(data)You can also use the pretty_generate method (which formats the output more
verbosely and nicely) or fast_generate (which doesn't do any of the security
checks generate performs, e. g. nesting deepness checks).
Caution
You should never use JSON.unsafe_load nor JSON.parse(str, create_additions: true) to parse untrusted user input,
as it can lead to remote code execution vulnerabilities.
To create a JSON document from a ruby data structure, you can call
JSON.generate like that:
json = JSON.generate [1, 2, {"a"=>3.141}, false, true, nil, 4..10]
# => "[1,2,{\"a\":3.141},false,true,null,\"4..10\"]"To get back a ruby data structure from a JSON document, you have to call JSON.parse on it:
JSON.parse json
# => [1, 2, {"a"=>3.141}, false, true, nil, "4..10"]Note, that the range from the original data structure is a simple
string now. The reason for this is, that JSON doesn't support ranges
or arbitrary classes. In this case the json library falls back to call
Object#to_json, which is the same as #to_s.to_json.
It's possible to add JSON support serialization to arbitrary classes by
simply implementing a more specialized version of the #to_json method, that
should return a JSON object (a hash converted to JSON with #to_json) like
this (don't forget the *a for all the arguments):
class Range
def to_json(*a)
{
'json_class' => self.class.name, # = 'Range'
'data' => [ first, last, exclude_end? ]
}.to_json(*a)
end
endThe hash key json_class is the class, that will be asked to deserialise the
JSON representation later. In this case it's Range, but any namespace of
the form A::B or ::A::B will do. All other keys are arbitrary and can be
used to store the necessary data to configure the object to be deserialised.
If the key json_class is found in a JSON object, the JSON parser checks
if the given class responds to the json_create class method. If so, it is
called with the JSON object converted to a Ruby hash. So a range can
be deserialised by implementing Range.json_create like this:
class Range
def self.json_create(o)
new(*o['data'])
end
endNow it possible to serialise/deserialise ranges as well:
json = JSON.generate [1, 2, {"a"=>3.141}, false, true, nil, 4..10]
# => "[1,2,{\"a\":3.141},false,true,null,{\"json_class\":\"Range\",\"data\":[4,10,false]}]"
JSON.parse json
# => [1, 2, {"a"=>3.141}, false, true, nil, 4..10]
json = JSON.generate [1, 2, {"a"=>3.141}, false, true, nil, 4..10]
# => "[1,2,{\"a\":3.141},false,true,null,{\"json_class\":\"Range\",\"data\":[4,10,false]}]"
JSON.unsafe_load json
# => [1, 2, {"a"=>3.141}, false, true, nil, 4..10]JSON.generate always creates the shortest possible string representation of a
ruby data structure in one line. This is good for data storage or network
protocols, but not so good for humans to read. Fortunately there's also
JSON.pretty_generate (or JSON.pretty_generate) that creates a more readable
output:
puts JSON.pretty_generate([1, 2, {"a"=>3.141}, false, true, nil, 4..10])
[
1,
2,
{
"a": 3.141
},
false,
true,
null,
{
"json_class": "Range",
"data": [
4,
10,
false
]
}
]There are also the methods Kernel#j for generate, and Kernel#jj for
pretty_generate output to the console, that work analogous to Core Ruby's p and
the pp library's pp methods.
Update the lib/json/version.rb file.
rbenv shell 2.6.5
rake build
gem push pkg/json-2.3.0.gem
rbenv shell jruby-9.2.9.0
rake build
gem push pkg/json-2.3.0-java.gem
Florian Frank mailto:flori@ping.de
Ruby License, see https://www.ruby-lang.org/en/about/license.txt.
The latest version of this library can be downloaded at
Online Documentation should be located at
