Class: Servus::Support::DataObject

Inherits:
SimpleDelegator
  • Object
show all
Defined in:
lib/servus/support/data_object.rb

Overview

A read-only wrapper around Hash data that provides accessor-style access.

When service results contain Hash data, DataObject wraps it so keys can be accessed as methods in addition to the standard bracket syntax. Nested Hashes are recursively wrapped, enabling chained access like data.user.address.city.

Non-Hash values (nil, String, Integer, Array, model instances) pass through unwrapped. This means data.user returns the original object when user is an ActiveRecord model, allowing natural method chaining (data.user.email).

DataObject inherits from SimpleDelegator, so all standard Hash methods ([], keys, each, as_json, ==, etc.) are delegated transparently.

Examples:

Accessor-style access

data = DataObject.wrap({ user: { email: "alice@example.com" } })
data.user.email   # => "alice@example.com"
data[:user]        # => { email: "alice@example.com" } (plain Hash)

Mixed values

data = DataObject.wrap({ user: user_model, metadata: { source: "api" } })
data.user.email       # => delegates to model's #email method
data.metadata.source  # => "api" (wrapped Hash accessor)

See Also:

Class Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args, &block) ⇒ Object (private)

Provides accessor-style access to Hash keys.

Only zero-argument, no-block calls trigger key lookup. Methods with arguments (e.g., fetch, dig) delegate to Hash normally. When the value is a Hash, it is recursively wrapped in a DataObject.

Parameters:

  • method_name (Symbol) —

    the method name to look up as a key

Returns:

  • (Object) —

    the value for the key, wrapped if it is a Hash

Raises:

  • (NoMethodError) —

    if the key does not exist



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# File 'lib/servus/support/data_object.rb', line 60

def method_missing(method_name, *args, &block)
  return super if args.any? || block

  hash = __getobj__
  if hash.key?(method_name.to_sym)
    self.class.wrap(hash[method_name.to_sym])
  elsif hash.key?(method_name.to_s)
    self.class.wrap(hash[method_name.to_s])
  else
    super
  end
end

Class Method Details

.wrap(data) ⇒ DataObject, ...

Wraps a value in a DataObject if it is a Hash.

Non-Hash values are returned unchanged. This is the preferred way to create DataObject instances, as it handles nil and non-Hash types safely.

Parameters:

  • data (Object) —

    the value to potentially wrap

Returns:

  • (DataObject) —

    if data is a Hash

  • (Array) —

    with Hash elements wrapped if data is an Array

  • (Object) —

    the original value otherwise



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# File 'lib/servus/support/data_object.rb', line 41

def self.wrap(data)
  case data
  when Hash  then new(data)
  when Array then data.map { |item| wrap(item) }
  else data
  end
end