How to unscope multiple models in rails?

Question

I am trying to unscope multiple model as below User Model which has acts_as_paranoid

class User
  acts_as_paranoid
  has_one :category
  has_one :brand
  has_one :item         

  INDEXED_FIELDS = {
    only: [:name],
    include: {
      category: { only: [:name] },
      item: { only:[:name] },
      brand: { only: [:name]},
    }
  }

  def custom_json
    Category.unscoped do
      Item.unscoped do
        Brand.unscoped do
          self.as_json(INDEXED_FIELDS)
        end
      end
    end
  end
end

User model has following association which also has acts_as_paranoid

Sample Category model, Brand and Item model have same code

class Category
  acts_as_paranoid
  belongs_to :user
end

Can I do this dynamically with 'N' number of models, like iterating over array as below

def custom_json
  [Category, Item, Brand].each do 
    # do unscoping 
  end
end

Association looks like

@NarasimhaReddy I want exclude default scope conditions from multiple models — Pramod Shinde, Oct 27 '17 at 09:55
That's fine. But what is the scenario of doing unscoping multiple models at a time. We can do while quering right? — Narasimha Reddy - Geeker, Oct 27 '17 at 09:58
Please provide `Category`, `Item`, `Brand` model files. So we could see relationships between them — Nikita Misharin, Oct 27 '17 at 10:02
When we call `self.as_json(INDEXED_FIELDS)`, it queries association to build json, I want unscope association and build the json. — Pramod Shinde, Oct 27 '17 at 10:03

Xavier Delamotte · Answer 1 · 2017-10-27T10:34:12.160

1

I think the approach you may have is to unscope the class manually, by setting default_scopes to [], and then putting it back.

classes_to_unscope = [Category, Item, Brand]
# remove default_scopes, saving them in previous_scopes
previous_scopes = classes_to_unscope.map do |klazz| 
  scopes = klazz.default_scopes
  klazz.default_scopes = []
  scopes
end 
self.as_json(INDEXED_FIELDS)
# put default_scopes back
classes_to_unscope.each_with_index do |klazz, i|
  klazz.default_scopes = previous_scopes[i]
end

edited Oct 27 '17 at 10:34

answered Oct 27 '17 at 10:20

Xavier Delamotte

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What is `klazz.default_scoping`, its giving error as undefined method? – Pramod Shinde Oct 27 '17 at 10:26
Sorry, typo, it was `default_scopes` – Xavier Delamotte Oct 27 '17 at 10:29

score 0 · Answer 2 · answered May 05 '21 at 11:59

As extra method:

def unscope_all(*models, &block)
    # the order does not matter, but preserve it
    blocks = [block] + models.reverse.map do |model|
      proc do |inner_block|
        model.unscoped { inner_block.call }
      end
    end

    blocks.inject do |inner, outer|
      proc { outer.call(inner) }
    end.call
  end

Then you would use it:

unscope_all(Category, Item, Brand) do 
    # do unscoping 
  end

unscoped pitfall: when leaving the block you loose the "unscopability", so make sure you don't return a relation (it won't be unscoped). Instead you have to resolve it in the block (e.g. by returning an array where(...).to_a.

How to unscope multiple models in rails?

2 Answers2