Polymorphic searches

When making searches from polymorphic models it is necessary to specify the type of model you are searching.

For example:

Given two models

class House < ActiveRecord::Base
  has_one :location, as: :locatable
end

class Location < ActiveRecord::Base
  belongs_to :locatable, polymorphic: true
end

Normally (without polymorphic relationship) you would be able to search as per below:

Location.ransack(locatable_number_eq: 100).result

However when this is searched you will get the following error

ActiveRecord::EagerLoadPolymorphicError: Can not eagerly load the polymorphic association :locatable

In order to search for locations by house number when the relationship is polymorphic you have to specify the type of records you will be searching and construct your search as below:

Location.ransack(locatable_of_House_type_number_eq: 100).result

note the _of_House_type_ added to the search key. This allows Ransack to correctly specify the table names in SQL join queries.

For namespaced models you should use a quoted string containing the standard Ruby module notation

Location.ransack('locatable_of_Residences::House_type_number_eq' => 100).result

The type must name a model. A suffix naming anything else, such as a constant that does not exist, a lowercase word or a class with no table, is not a polymorphic reference, and the key is treated like any other unknown attribute: ignored by default, or raised as Ransack::InvalidSearchError when ignore_unknown_conditions is false.

Location.ransack(locatable_of_Nowhere_type_number_eq: 100).result
# => every location; the condition is ignored

Location.ransack!(locatable_of_Nowhere_type_number_eq: 100)
# Ransack::InvalidSearchError: Invalid search term locatable_of_Nowhere_type_number_eq