Using hashes for structs

struct.rb

# using a predefined hash
hash = { field1: "foo", field2: "bar" }
HashStruct = Struct.new(*hash.keys, keyword_init: true)

hash_struct = HashStruct.new(hash)
hash_struct.field1 # => "foo"
hash_struct.field2 # => "bar"
hash_struct.field3 # => ERROR!


# using an array
ary = [:field1, :field2]
AryStruct = Struct.new(*ary, keyword_init: true)

ary_hash = {}
ary_hash[:field1] = "foo"
ary_hash[:field2] = "bar"

ary_struct = AryStruct.new(ary_hash)
ary_struct.field1 # => "foo"
ary_struct.field2 # => "bar"
ary_struct.field3 # => ERROR!

Thanks for the gist. I have one question

hash = { 'company' => [{ 'name' => 'Company1', 'departments': [{ 'name' => 'Management' }] },
                       { 'name' => 'Company2', 'departments': [{ 'name' => 'Engineering' }] }] }

How can we create a Struct class for above-nested Hash? so that we can access like "company.first.departments.first"

@sajanbasnet75 I havent really thought aboutt this use case too much. I really only thought about top-level objects.

For a nested hash to use dot notation, if youre using Rails, you could do something like this:

h = ActiveSupport::InheritableOptions.new({ 'company' => [{ 'name' => 'Company1', 'departments': [{ 'name' => 'Management' }] },
                                                                                                    { 'name' => 'Company2', 'departments': [{ 'name' => 'Engineering' }] }] )})

which then allows you to do:

h.company.first.departments.first

Thanks for the reply @ParamagicDev

Unfortunately, I am trying to do this on plain ruby, also using Struct rather than openStruct.