what is "!map:HashWithIndifferentAccess "?

I read the typo migration code file 004_add_sidebars_.rb and found
these:

      Bare4Sidebar.create(:active_position=>0, :controller=>'page',
:active_config=>'--- !map:HashWithIndifferentAccess
      maximum_pages: "10"')

I'm confused what does it meaning? work for?
anyone help~

Guan,

HashWithIndifferentAccess is just like any other hash except that the
key 'somekey' will be the same as the key :somekey.

For example if you have a regular hash like the following

hash = Hash.new({:somekey => 'testing'})
hash[:somekey]

=> testing

hash['somekey']

=> nil

Notice how the key 'somekey' is not the same as the key :somekey

hash = HashWithIndifferentAccess.new({:somekey => 'testing'})
hash[:somekey]

=> 'testing'

hash['somekey']

=> 'testing'

Here the key 'somekey' and :somekey are the same.

Understand?

I read the typo migration code file 004_add_sidebars_.rb and found
these:

     Bare4Sidebar.create(:active_position=>0, :controller=>'page',
:active_config=>'--- !map:HashWithIndifferentAccess
     maximum_pages: "10"')

I'm confused what does it meaning? work for?

That looks like yaml serialized data.

Fred