Class: Megam::JSONCompat

Inherits:
Object
  • Object
show all
Defined in:
lib/megam/core/json_compat.rb

Constant Summary collapse

JSON_MAX_NESTING = 
1000
JSON_CLAZ = 
"json_claz".freeze
MEGAM_AUTH = 
"Megam::Auth".freeze
MEGAM_ERROR = 
"Megam::Error".freeze
MEGAM_ACCOUNT = 
"Megam::Account".freeze
MEGAM_NODE = 
"Megam::Node".freeze
MEGAM_APPDEFNS = 
"Megam::AppDefns".freeze
MEGAM_APPREQS = 
"Megam::AppRequest".freeze
MEGAM_BOLTREQS = 
"Megam::BoltRequest".freeze
MEGAM_BOLTDEFNS = 
"Megam::BoltDefns".freeze
MEGAM_NODECOLLECTION = 
"Megam::NodeCollection".freeze
MEGAM_APPDEFNSCOLLECTION = 
"Megam::AppDefnCollection".freeze
MEGAM_APPREQSCOLLECTION = 
"Megam::AppRequestCollection".freeze
MEGAM_BOLTREQSCOLLECTION = 
"Megam::BoltRequestCollection".freeze
MEGAM_BOLTDEFNSCOLLECTION = 
"Megam::BoltDefnCollection".freeze
MEGAM_REQUEST = 
"Megam::Request".freeze
MEGAM_REQUESTCOLLECTION = 
"Megam::RequestCollection".freeze
MEGAM_PREDEF = 
"Megam::Predef".freeze
MEGAM_PREDEFCOLLECTION = 
"Megam::PredefCollection".freeze
MEGAM_PREDEFCLOUD = 
"Megam::PredefCloud".freeze
MEGAM_PREDEFCLOUDCOLLECTION = 
"Megam::PredefCloudCollection".freeze
MEGAM_CLOUDTOOL = 
"Megam::CloudTool".freeze
MEGAM_CLOUDTOOLCOLLECTION = 
"Megam::CloudToolCollection".freeze
MEGAM_CLOUDTEMPLATE = 
"Megam::CloudTemplate".freeze
MEGAM_CLOUDTEMPLATECOLLECTION = 
"Megam::CloudTemplateCollection".freeze
MEGAM_CLOUDINSTRUCTION = 
"Megam::CloudInstruction".freeze
MEGAM_CLOUDINSTRUCTIONCOLLECTION = 
"Megam::CloudInstructionCollection".freeze
MEGAM_CLOUDINSTRUCTIONGROUP = 
"Megam::CloudInstructionGroup".freeze

Class Method Summary collapse

Class Method Details

.class_for_json_class(json_class) ⇒ Object

Map JSON_CLAZ to a Class object. We use a case instead of a Hash assigned to a constant because otherwise this file could not be loaded until all the constants were defined, which means you'd have to load the world to get json.



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# File 'lib/megam/core/json_compat.rb', line 122

def class_for_json_class(json_class)
  case json_class
  when MEGAM_ERROR
    Megam::Error
  when MEGAM_AUTH
    Megam::Auth
  when MEGAM_ACCOUNT
    Megam::Account
  when MEGAM_NODE
    Megam::Node
  when MEGAM_APPDEFNS
    Megam::Appdefns
  when MEGAM_APPREQS
    Megam::Appreqs
  when MEGAM_BOLTREQS
    Megam::Boltreqs
  when MEGAM_BOLTDEFNS
    Megam::Boltdefns
  when MEGAM_NODECOLLECTION
    Megam::NodeCollection
  when MEGAM_APPDEFNSCOLLECTION
    Megam::AppdefnsCollection
  when MEGAM_APPREQSCOLLECTION
    Megam::AppreqsCollection
  when MEGAM_BOLTREQSCOLLECTION
    Megam::BoltreqsCollection
  when MEGAM_BOLTDEFNSCOLLECTION
    Megam::BoltdefnsCollection
  when MEGAM_REQUEST
    Megam::Request
  when MEGAM_REQUESTCOLLECTION
    Megam::RequestCollection
  when MEGAM_PREDEF
    Megam::Predef
  when MEGAM_PREDEFCOLLECTION
    Megam::PredefCollection
  when MEGAM_PREDEFCLOUD
    Megam::PredefCloud
  when MEGAM_PREDEFCLOUDCOLLECTION
    Megam::PredefCloudCollection
  when MEGAM_CLOUDTOOL
    Megam::CloudTool
  when MEGAM_CLOUDTOOLCOLLECTION
    Megam::CloudToolCollection
  when MEGAM_CLOUDTEMPLATE
    Megam::CloudTemplate
  when MEGAM_CLOUDTEMPLATECOLLECTION
    Megam::CloudTemplateCollection
  when MEGAM_CLOUDINSTRUCTION
    Megam::CloudInstruction
  when MEGAM_CLOUDINSTRUCTIONGROUP
    Megam::CloudInstructionGroup
  when MEGAM_CLOUDINSTRUCTIONCOLLECTION
    Megam::CloudInstructionCollection
  else
  raise JSON::ParserError, "Unsupported `json_class` type '#{json_class}'"
  end
end

.from_json(source, opts = {}) ⇒ Object

Just call the JSON gem's parse method with a modified :max_nesting field



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# File 'lib/megam/core/json_compat.rb', line 65

def from_json(source, opts = {})
  obj = ::Yajl::Parser.parse(source)
  # JSON gem requires top level object to be a Hash or Array (otherwise
  # you get the "must contain two octets" error). Yajl doesn't impose the
  # same limitation. For compatibility, we re-impose this condition.
  unless obj.kind_of?(Hash) or obj.kind_of?(Array)
    raise JSON::ParserError, "Top level JSON object must be a Hash or Array. (actual: #{obj.class})"
  end

  # The old default in the json gem (which we are mimicing because we
  # sadly rely on this misfeature) is to "create additions" i.e., convert
  # JSON objects into ruby objects. Explicit :create_additions => false
  # is required to turn it off.
  if opts[:create_additions].nil? || opts[:create_additions]
    map_to_rb_obj(obj)
  else
  obj
  end
end

.map_hash_to_rb_obj(json_hash) ⇒ Object 



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# File 'lib/megam/core/json_compat.rb', line 103

def map_hash_to_rb_obj(json_hash)
  json_hash.each do |key, value|
    json_hash[key] = map_to_rb_obj(value)
  end
  json_hash
end

.map_to_rb_obj(json_obj) ⇒ Object

Look at an object that's a basic type (from json parse) and convert it to an instance of Megam classes if desired.



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# File 'lib/megam/core/json_compat.rb', line 87

def map_to_rb_obj(json_obj)
  case json_obj
  when Hash
    mapped_hash = map_hash_to_rb_obj(json_obj)
    if json_obj.has_key?(JSON_CLAZ) && (class_to_inflate = class_for_json_class(json_obj[JSON_CLAZ]))
    class_to_inflate.json_create(mapped_hash)
    else
    mapped_hash
    end
  when Array
    json_obj.map {|e| map_to_rb_obj(e) }
  else
  json_obj
  end
end

.opts_add_max_nesting(opts) ⇒ Object

Increase the max nesting for JSON, which defaults to 19, and isn't enough for some (for example, a Node within a Node) structures.



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# File 'lib/megam/core/json_compat.rb', line 56

def opts_add_max_nesting(opts)
  if opts.nil? || !opts.has_key?(:max_nesting)
    opts = opts.nil? ? Hash.new : opts.clone
    opts[:max_nesting] = JSON_MAX_NESTING
  end
  opts
end

.to_json(obj, opts = nil) ⇒ Object 



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# File 'lib/megam/core/json_compat.rb', line 110

def to_json(obj, opts = nil)
  obj.to_json(opts_add_max_nesting(opts))
end

.to_json_pretty(obj, opts = nil) ⇒ Object 



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# File 'lib/megam/core/json_compat.rb', line 114

def to_json_pretty(obj, opts = nil)
  ::JSON.pretty_generate(obj, opts_add_max_nesting(opts))
end