使用 rails scopes gem 限定整数值的问题

Question

I have a model CoffeeShops which includes an integer value wifi_restrictions.

The integer value of this field will represent the number of hours you can use the wifi.

I'm trying to set up scopes for this so that I can search

CoffeeShop.has_wifi_restrictions

...and it will return all coffee shops with a wifi_restrictions value which is greater than 0.

I'm using the rails has_scope gem: https://github.com/plataformatec/has_scope

---

I have tried every variation I can think of to implement the scope in the model, but the syntax of this block is making my head spin.

I have also tried both

has_scope :has_wifi_restrictions, type: :boolean

as well as

has_scope :has_wifi_restrictions, type: :integer

I'm not sure what this should be. A side question here is whether the scope block in the model essentially turns the integer value into a boolean value under the new scope method.

ie

my_coffee_shop.wifi_restrictions = 1

converts into

my_coffee_shop.has_wifi_restrictions = true

I'm not sure exactly how that works or how to properly implement it.

---

I know that in my model I need something like the following:

class CoffeeShop < ApplicationRecord
          scope :has_wifi_restrictions, ->(hours) { where(wifi_restrictions: hours.positive?) }
end

And in the controller I need something like:

class CoffeeShopsController < ApplicationController
  has_scope :has_wifi_restrictions, type: :boolean
end

When I try to do the search

CoffeeShop.has_wifi_restrictions

I get the following:

ArgumentError: wrong number of arguments (given 0, expected 1)

-

I appreciate there's a number of questions here all bundled together, but I would be grateful for both solutions, as well as general advice in understanding how to use scope.

Answer 1

The has_wifi_restrictions scope that you defined required that you pass in the number of hours. That does not seem to match the goal you stated (all coffee shops that have wifi restrictions). The latter would be something like

class CoffeeShop < ApplicationRecord
  scope :has_wifi_restrictions, -> { where('hours > 0') }
end

Defining a scope is fundamentally no different than defining a query (and has nothing to do with the has_scope gem).

To use that scope with the has_scope gem, you'd define a boolean scope in your controller:

class CoffeeShopsController << ApplicationController
  has_scope :has_wifi_restrictions, type: :boolean
end

With that, the has_wifi_restrictions scope will be applied to CoffeeShop only when a 'has_wifi_restrictions=true' is part of the query string routed to the CoffeeShopsController.