Rails ActiveRelation to hash

Question

I need to hashify ActiveRelation! For example I have such AR

arel = MyClass.page(options[:page]).per(options[:per]) 

Is here a way simple to create hash with primary keys of MyTable as keys in hash

Ex1:

[#<Object id: 44, name: "name44" >, #<Object id: 2, name: "name2" >, #<Object id: 110, name: "name110">]
=>
{44=>"name44", 2=>"name2",110=>"name110"}

Ex2:

[#<Object id: 44, name: "name44" >, #<Object id: 2, name: "name2" >, #<Object id: 110, name: "name110">]
=>
{44=>{:id=>44, :name=>"name44", 2=>{:id=>2,:name=>"name2"},110=>{:id=>110,:name=>"name110"}}

Answer 1

Try index_by:

MyClass.limit(20).all.index_by(&:id)

http://api.rubyonrails.org/classes/Enumerable.html#method-i-index_by

Answer 2

You could do that manually, there is no function defined in Array class.

hsh = {}
objects.each { |u| hsh.merge!({ u.id => { :name => u.name } })

Answer 3

Try serializable_hash, documented here.