In home_Controller code change

[deependersingla]

In home_controller.rb
index method

@user=User.all.to_a from @user=User.all (According to mongoid documentation) , otherwise user will get error that user is a nil class.

[BandanaPandey]

Hi, you are right, but you have misunderstood something here.
@users is Mongoid::Criteria .
Criteria is like Relation object in ActiveRecord.
In case of Mongoid, the Mongoid::Criteria module is the core object for querying MongoDB. Every time a query is fired, a criteria is created. Once you have a criteria, you can get the elements, executing an actual query to the database, with a method that is supposed to iterate over the elements or return one element, for eg: .to_a, .each, .map, etc.

So here on @users we have already used @users.each in views/home/index.html.erb to fetch the elements from the database.

As a result there is no need to use @users = User.all.to_a , as we are using @users.each, so no error occurs.