Class: Chef::JSONCompat

Inherits:
Object show all
Defined in:
lib/chef/json_compat.rb

Constant Summary collapse

JSON_MAX_NESTING = 
1000
JSON_CLASS = 
"json_class".freeze
CHEF_APICLIENT = 
"Chef::ApiClient".freeze
CHEF_COOKBOOKVERSION = 
"Chef::CookbookVersion".freeze
CHEF_DATABAG = 
"Chef::DataBag".freeze
CHEF_DATABAGITEM = 
"Chef::DataBagItem".freeze
CHEF_ENVIRONMENT = 
"Chef::Environment".freeze
CHEF_NODE = 
"Chef::Node".freeze
CHEF_ROLE = 
"Chef::Role".freeze
CHEF_SANDBOX = 
"Chef::Sandbox".freeze
CHEF_RESOURCE = 
"Chef::Resource".freeze
CHEF_RESOURCECOLLECTION = 
"Chef::ResourceCollection".freeze

Class Method Summary collapse

Class Method Details

.class_for_json_class(json_class) ⇒ Object

Map json_class 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, which would make knife very slow.



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# File 'lib/chef/json_compat.rb', line 113

def class_for_json_class(json_class)
  case json_class
  when CHEF_APICLIENT
    Chef::ApiClient
  when CHEF_COOKBOOKVERSION
    Chef::CookbookVersion
  when CHEF_DATABAG
    Chef::DataBag
  when CHEF_DATABAGITEM
    Chef::DataBagItem
  when CHEF_ENVIRONMENT
    Chef::Environment
  when CHEF_NODE
    Chef::Node
  when CHEF_ROLE
    Chef::Role
  when CHEF_SANDBOX
    # a falsey return here will disable object inflation/"create
    # additions" in the caller. In Chef 11 this is correct, we just have
    # a dummy Chef::Sandbox class for compat with Chef 10 servers.
    false
  when CHEF_RESOURCE
    Chef::Resource
  when CHEF_RESOURCECOLLECTION
    Chef::ResourceCollection
  when /^Chef::Resource/
    Chef::Resource.find_subclass_by_name(json_class)
  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/chef/json_compat.rb', line 54

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/chef/json_compat.rb', line 93

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 Chef classes if desired.



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# File 'lib/chef/json_compat.rb', line 77

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_CLASS) && (class_to_inflate = class_for_json_class(json_obj[JSON_CLASS]))
      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

See CHEF-1292/PL-538. 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/chef/json_compat.rb', line 45

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/chef/json_compat.rb', line 100

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/chef/json_compat.rb', line 104

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