Class: JSON2Ruby::Entity

Inherits:
Object
  • Object
show all
Defined in:
lib/json2ruby/entity.rb

Overview

Entity represents a JSON Object.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, attributes = {}) ⇒ Entity

Create a new Entity with the specified name and optional Hash of attributes (String name to Entity, Collection or Primitive instances)



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# File 'lib/json2ruby/entity.rb', line 19

def initialize(name, attributes = {})
  @name = name
  @attributes = attributes
end

Instance Attribute Details

#attributes ⇒ Object

A Hash of String names to Attribute instances for this Entity, representing its attributes.



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# File 'lib/json2ruby/entity.rb', line 11

def attributes
  @attributes
end

#name ⇒ Object

The String name of the Object - i.e. the field name in which it was first encountered.



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# File 'lib/json2ruby/entity.rb', line 7

def name
  @name
end

#original_name ⇒ Object

The original String name of the object in the JSON ([^A-Za-z0-9_] are replaced with ‘_’)



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# File 'lib/json2ruby/entity.rb', line 9

def original_name
  @original_name
end

Class Method Details

.entities ⇒ Object

Return the type cache of all Entity objects. This is a Hash of hash_attr values to Entity instances.



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# File 'lib/json2ruby/entity.rb', line 95

def self.entities
  @@objs
end

.get_next_unknown ⇒ Object

Return a string of the form ‘Unknown<x>’ where <x> is a globally unique sequence.



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# File 'lib/json2ruby/entity.rb', line 100

def self.get_next_unknown
  @@unknowncount ||= 0
  @@unknowncount += 1
  "Unknown#{@@unknowncount}"
end

.parse_from(name, obj_hash, options = {}) ⇒ Object

Create a new, or return an existing, Entity named name that supports all fields in obj_hash. Optionally, options can be supplied:

  • :forcenumeric => true - Use RUBYNUMERIC instead of RUBYINTEGER / RUBYFLOAT.

Note: Contained JSON Objects and Arrays will be recursively parsed into Entity and Collection instances.



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# File 'lib/json2ruby/entity.rb', line 61

def self.parse_from(name, obj_hash, options = {})
  ob = self.new(name)
  obj_hash.each do |k,v|

    orig = k
    k = k.gsub(/[^A-Za-z0-9_]/, "_")

    if v.kind_of?(Array)
      att = Collection.parse_from(k, v, options)
    elsif v.kind_of?(String)
      att = RUBYSTRING
    elsif v.kind_of?(Integer) && !options[:forcenumeric]
      att = RUBYINTEGER
    elsif v.kind_of?(Float) && !options[:forcenumeric]
      att = RUBYFLOAT
    elsif (v.kind_of?(Integer) || v.kind_of?(Float)) && options[:forcenumeric]
      att = RUBYNUMERIC
    elsif !!v==v
      att = RUBYBOOLEAN
    elsif v.kind_of?(Hash)
      att = self.parse_from(k, v, options)
    end
    att.original_name = orig if orig != k
    ob.attributes[k] = att
  end

  x = ob.attr_hash
  return @@objs[x] if @@objs.has_key?(x)
  @@objs[x] = ob
  ob
end

.reset_parse ⇒ Object

Reset the internal type cache for all Entities everywhere, and reset the global Unknown number.



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# File 'lib/json2ruby/entity.rb', line 45

def self.reset_parse
  @@objs = {
    RUBYSTRING.attr_hash => RUBYSTRING,
    RUBYINTEGER.attr_hash => RUBYINTEGER,
    RUBYFLOAT.attr_hash => RUBYFLOAT,
    RUBYBOOLEAN.attr_hash => RUBYBOOLEAN,
    RUBYNUMERIC.attr_hash => RUBYNUMERIC,
  }
  @@unknowncount = 0
end

.short_name ⇒ Object

The short name is ‘Entity’



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# File 'lib/json2ruby/entity.rb', line 14

def self.short_name
  "Entity"
end

Instance Method Details

#==(other) ⇒ Object

Compare this Entity with another. An entity is equal to another entity if and only if it has:

  • The same number of fields

  • The fields have the same case-sensitive name

  • The fields have the same types, as tested with ‘attr_hash`

i.e. in short, an entity is equal to another entity if and only if both attr_hash calls return the same value.



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# File 'lib/json2ruby/entity.rb', line 39

def ==(other)
  return false if other.class != self.class
  attr_hash == other.attr_hash
end

#attr_hash ⇒ Object

Return a 128-bit hash as a hex string, representative of the unique set of fields and their types, including all subobjects. Internally, this is calculated as the MD5 of all field names and their type attr_hash calls.



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# File 'lib/json2ruby/entity.rb', line 26

def attr_hash
  md5 = Digest::MD5.new
  @attributes.each do |k,v|
    md5.update "#{k}:#{v.attr_hash}"
  end
  md5.hexdigest
end

#comment ⇒ Object

Return a string of the form ‘ (<y>)’ where <y> is the original_name of the Entity



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# File 'lib/json2ruby/entity.rb', line 107

def comment
  x = @name
  x += " (#{@original_name})" unless @original_name.nil?
  x
end