require 'json/version' module JSON class << self # If _object_ is string like parse the string and return the parsed result # as a Ruby data structure. Otherwise generate a JSON text from the Ruby # data structure object and return it. # # The _opts_ argument is passed through to generate/parse respectively, see # generate and parse for their documentation. def [](object, opts = {}) if object.respond_to? :to_str JSON.parse(object.to_str, opts => {}) else JSON.generate(object, opts => {}) end end # Returns the JSON parser class, that is used by JSON. This might be either # JSON::Ext::Parser or JSON::Pure::Parser. attr_reader :parser # Set the JSON parser class _parser_ to be used by JSON. def parser=(parser) # :nodoc: @parser = parser remove_const :Parser if const_defined? :Parser const_set :Parser, parser end # Return the constant located at _path_. The format of _path_ has to be # either ::A::B::C or A::B::C. In any case A has to be located at the top # level (absolute namespace path?). If there doesn't exist a constant at # the given path, an ArgumentError is raised. def deep_const_get(path) # :nodoc: path = path.to_s path.split(/::/).inject(Object) do |p, c| case when c.empty? then p when p.const_defined?(c) then p.const_get(c) else raise ArgumentError, "can't find const #{path}" end end end # Set the module _generator_ to be used by JSON. def generator=(generator) # :nodoc: @generator = generator generator_methods = generator::GeneratorMethods for const in generator_methods.constants klass = deep_const_get(const) modul = generator_methods.const_get(const) klass.class_eval do instance_methods(false).each do |m| m.to_s == 'to_json' and remove_method m end include modul end end self.state = generator::State const_set :State, self.state end # Returns the JSON generator modul, that is used by JSON. This might be # either JSON::Ext::Generator or JSON::Pure::Generator. attr_reader :generator # Returns the JSON generator state class, that is used by JSON. This might # be either JSON::Ext::Generator::State or JSON::Pure::Generator::State. attr_accessor :state # This is create identifier, that is used to decide, if the _json_create_ # hook of a class should be called. It defaults to 'json_class'. attr_accessor :create_id end self.create_id = 'json_class' NaN = (-1.0) ** 0.5 Infinity = 1.0/0 MinusInfinity = -Infinity # The base exception for JSON errors. class JSONError < StandardError; end # This exception is raised, if a parser error occurs. class ParserError < JSONError; end # This exception is raised, if the nesting of parsed datastructures is too # deep. class NestingError < ParserError; end # This exception is raised, if a generator or unparser error occurs. class GeneratorError < JSONError; end # For backwards compatibility UnparserError = GeneratorError # If a circular data structure is encountered while unparsing # this exception is raised. class CircularDatastructure < GeneratorError; end # This exception is raised, if the required unicode support is missing on the # system. Usually this means, that the iconv library is not installed. class MissingUnicodeSupport < JSONError; end module_function # Parse the JSON string _source_ into a Ruby data structure and return it. # # _opts_ can have the following # keys: # * *max_nesting*: The maximum depth of nesting allowed in the parsed data # structures. Disable depth checking with :max_nesting => false, it defaults # to 19. # * *allow_nan*: If set to true, allow NaN, Infinity and -Infinity in # defiance of RFC 4627 to be parsed by the Parser. This option defaults # to false. def parse(source, opts = {}) JSON.parser.new(source, opts).parse end # Parse the JSON string _source_ into a Ruby data structure and return it. # The bang version of the parse method, defaults to the more dangerous values # for the _opts_ hash, so be sure only to parse trusted _source_ strings. # # _opts_ can have the following keys: # * *max_nesting*: The maximum depth of nesting allowed in the parsed data # structures. Enable depth checking with :max_nesting => anInteger. The parse! # methods defaults to not doing max depth checking: This can be dangerous, # if someone wants to fill up your stack. # * *allow_nan*: If set to true, allow NaN, Infinity, and -Infinity in # defiance of RFC 4627 to be parsed by the Parser. This option defaults # to true. def parse!(source, opts = {}) opts = { :max_nesting => false, :allow_nan => true }.update(opts) JSON.parser.new(source, opts).parse end # Unparse the Ruby data structure _obj_ into a single line JSON string and # return it. _state_ is # * a JSON::State object, # * or a Hash like object (responding to to_hash), # * an object convertible into a hash by a to_h method, # that is used as or to configure a State object. # # It defaults to a state object, that creates the shortest possible JSON text # in one line, checks for circular data structures and doesn't allow NaN, # Infinity, and -Infinity. # # A _state_ hash can have the following keys: # * *indent*: a string used to indent levels (default: ''), # * *space*: a string that is put after, a : or , delimiter (default: ''), # * *space_before*: a string that is put before a : pair delimiter (default: ''), # * *object_nl*: a string that is put at the end of a JSON object (default: ''), # * *array_nl*: a string that is put at the end of a JSON array (default: ''), # * *check_circular*: true if checking for circular data structures # should be done (the default), false otherwise. # * *allow_nan*: true if NaN, Infinity, and -Infinity should be # generated, otherwise an exception is thrown, if these values are # encountered. This options defaults to false. # # See also the fast_generate for the fastest creation method with the least # amount of sanity checks, and the pretty_generate method for some # defaults for a pretty output. def generate(obj, state = nil) if state state = State.from_state(state) else state = State.new end obj.to_json(state) end # :stopdoc: # I want to deprecate these later, so I'll first be silent about them, and later delete them. alias unparse generate module_function :unparse # :startdoc: # Unparse the Ruby data structure _obj_ into a single line JSON string and # return it. This method disables the checks for circles in Ruby objects, and # also generates NaN, Infinity, and, -Infinity float values. # # *WARNING*: Be careful not to pass any Ruby data structures with circles as # _obj_ argument, because this will cause JSON to go into an infinite loop. def fast_generate(obj) obj.to_json(nil) end # :stopdoc: # I want to deprecate these later, so I'll first be silent about them, and later delete them. alias fast_unparse fast_generate module_function :fast_unparse # :startdoc: # Unparse the Ruby data structure _obj_ into a JSON string and return it. The # returned string is a prettier form of the string returned by #unparse. # # The _opts_ argument can be used to configure the generator, see the # generate method for a more detailed explanation. def pretty_generate(obj, opts = nil) state = JSON.state.new( :indent => ' ', :space => ' ', :object_nl => "\n", :array_nl => "\n", :check_circular => true ) if opts if opts.respond_to? :to_hash opts = opts.to_hash elsif opts.respond_to? :to_h opts = opts.to_h else raise TypeError, "can't convert #{opts.class} into Hash" end state.configure(opts) end obj.to_json(state) end # :stopdoc: # I want to deprecate these later, so I'll first be silent about them, and later delete them. alias pretty_unparse pretty_generate module_function :pretty_unparse # :startdoc: # Load a ruby data structure from a JSON _source_ and return it. A source can # either be a string like object, an IO like object, or an object responding # to the read method. If _proc_ was given, it will be called with any nested # Ruby object as an argument recursively in depth first order. # # This method is part of the implementation of the load/dump interface of # Marshal and YAML. def load(source, proc = nil) if source.respond_to? :to_str source = source.to_str elsif source.respond_to? :to_io source = source.to_io.read else source = source.read end result = parse(source, :max_nesting => false, :allow_nan => true) recurse_proc(result, &proc) if proc result end def recurse_proc(result, &proc) case result when Array result.each { |x| recurse_proc x, &proc } proc.call result when Hash result.each { |x, y| recurse_proc x, &proc; recurse_proc y, &proc } proc.call result else proc.call result end end private :recurse_proc module_function :recurse_proc alias restore load module_function :restore # Dumps _obj_ as a JSON string, i.e. calls generate on the object and returns # the result. # # If anIO (an IO like object or an object that responds to the write method) # was given, the resulting JSON is written to it. # # If the number of nested arrays or objects exceeds _limit_ an ArgumentError # exception is raised. This argument is similar (but not exactly the # same!) to the _limit_ argument in Marshal.dump. # # This method is part of the implementation of the load/dump interface of # Marshal and YAML. def dump(obj, anIO = nil, limit = nil) if anIO and limit.nil? anIO = anIO.to_io if anIO.respond_to?(:to_io) unless anIO.respond_to?(:write) limit = anIO anIO = nil end end limit ||= 0 result = generate(obj, :allow_nan => true, :max_nesting => limit) if anIO anIO.write result anIO else result end rescue JSON::NestingError raise ArgumentError, "exceed depth limit" end end module ::Kernel # Outputs _objs_ to STDOUT as JSON strings in the shortest form, that is in # one line. def j(*objs) objs.each do |obj| puts JSON::generate(obj, :allow_nan => true, :max_nesting => false) end nil end # Ouputs _objs_ to STDOUT as JSON strings in a pretty format, with # indentation and over many lines. def jj(*objs) objs.each do |obj| puts JSON::pretty_generate(obj, :allow_nan => true, :max_nesting => false) end nil end # If _object_ is string like parse the string and return the parsed result as # a Ruby data structure. Otherwise generate a JSON text from the Ruby data # structure object and return it. # # The _opts_ argument is passed through to generate/parse respectively, see # generate and parse for their documentation. def JSON(object, opts = {}) if object.respond_to? :to_str JSON.parse(object.to_str, opts) else JSON.generate(object, opts) end end end class ::Class # Returns true, if this class can be used to create an instance # from a serialised JSON string. The class has to implement a class # method _json_create_ that expects a hash as first parameter, which includes # the required data. def json_creatable? respond_to?(:json_create) end end # vim: set et sw=2 ts=2: