Is it possible to have a scope with optional arguments?

I used scope :name, ->(arg1, arg2 = value) { ... } a few weeks ago, it worked well, if my memory's correct. To use with ruby 1.9+

Ruby 1.9 extended blocks to have the same features as methods do (default values are among them):

scope :cheap, lambda{|max_price=20.0| where("price < ?", max_price)}

Call:

Model.cheap
Model.cheap(15)

Yes. Just use a * like you would in a method.

scope :print_args, lambda {|*args|
    puts args
}

You can conditionally modify your scope based on a given argument.

scope :random, ->(num = nil){ num ? order('RANDOM()').limit(num) : order('RANDOM()') }

Usage:

Advertisement.random # => returns all records randomized
Advertisement.random(1) # => returns 1 random record

Or, you can provide a default value.

scope :random, ->(num = 1000){ order('RANDOM()').limit(num) }

Usage:

Product.random # => returns 1,000 random products
Product.random(5) # => returns 5 random products

NOTE: The syntax shown for RANDOM() is specific to Postgres. The syntax shown is Rails 4.

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