Document "critical" differences between Mongoid and ActiveRecord about mongoid-site HOT 1 CLOSED

+1

just wasted 1 hour trying to figure out why the Child relations were not saved automatically until i stumbled over this ticket (https://github.com/mongoid/mongoid/issues/1071)

The docs clearly state that

Append one or many child posts, saving them if the person is persisted.
person.posts << Post.new
person.posts.push(Post.new)
person.posts.concat([ post ])

Appends and returns a new child post from the attirbutes.
person.posts.build(title: "Berlin never sleeps.")
person.posts.new(title: "Berlin never sleeps.")

which is just incorrect.

The note on autosave is just to be found on http://mongoid.org/docs/upgrading.html, which is likely to be overseen.

from mongoid-site.