method

preloader_for

v5.0.0.1 - Show latest stable - Class: ActiveRecord::Associations::Preloader

preloader_for(reflection, owners, rhs_klass)

private

Returns a class containing the logic needed to load preload the data and attach it to a relation. For example +Preloader::Association+ or +Preloader::HasManyThrough+. The class returned implements a `run` method that accepts a preloader.

# File activerecord/lib/active_record/associations/preloader.rb, line 194
      def preloader_for(reflection, owners, rhs_klass)
        return NullPreloader unless rhs_klass

        if owners.first.association(reflection.name).loaded?
          return AlreadyLoaded
        end
        reflection.check_preloadable!

        case reflection.macro
        when :has_many
          reflection.options[:through] ? HasManyThrough : HasMany
        when :has_one
          reflection.options[:through] ? HasOneThrough : HasOne
        when :belongs_to
          BelongsTo
        end
      end

preloader_for

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