Getting undefined method `sorted_by' when trying to use filterrific gem on a rails app

Question

I'm trying to use the filterrific gem on a rails app to filter cities by a price lower than $1000 for example. - https://github.com/jhund/filterrific

but can't seem to set it up, i've added the code to the model and controllers but I get undefined method `sorted_by' for #<City::ActiveRecord_Relation:0x00007fc191173040> Did you mean? sort_by method `sorted_by' for #<City::ActiveRecord_Relation:0x00007fc191173040> Did you mean? sort_by

Model -

class City < ApplicationRecord
  has_one :guide, dependent: :destroy

  filterrific(
    default_filter_params: { sorted_by: 'created_at_desc' },
    available_filters: %i[
      sorted_by
      search_query
      with_created_at_gte
    ]
  )
end

Controller -

class CitiesController < ApplicationController
  def index
    @cities = City.all

    (@filterrific = initialize_filterrific(
      City,
      params[:filterrific]
    )) || return
    @cities = @filterrific.find.page(params[:page])

    respond_to do |format|
      format.html
      format.js
    end
  end

Schema -

  create_table "cities", force: :cascade do |t|
    t.string "name"
    t.string "internet"
    t.datetime "created_at", precision: 6, null: false
    t.datetime "updated_at", precision: 6, null: false
    t.string "weather"
    t.string "image"
    t.string "country"
    t.string "price"
  end

Answer 1

It looks like you have copied and pasted the example from the documentation without really understanding what you are trying to do.

The error message is coming from your default_filter_params here:

filterrific(
  default_filter_params: { sorted_by: 'created_at_desc' }, <<<
  ...
)

For this to work you need a sorted_by scope which takes a parameter 'created_at_desc'. There are examples in the documentation here: http://filterrific.clearcove.ca/pages/active_record_scope_patterns.html

An example for the sorted_by scope would be:

scope :sorted_by, (lambda do |sort_option|

  direction = (sort_option =~ /desc$/) ? 'desc' : 'asc'

  case sort_option.to_s
  when /^created_at_/
    order("cities.created_at #{ direction }")
  when /^name_/
    order("cities.name #{ direction }")
  else
    raise(ArgumentError, "Invalid sort option: #{ sort_option.inspect }")
  end
end)

to filter by price you will also need a scope like so:

scope :with_price_lte, (lambda do |price|
  where('price >= ?', price)
end)

so your model filterrific clause should look like:

filterrific(
  default_filter_params: { sorted_by: 'created_at_desc' },
  available_filters: %i[
    sorted_by
    with_price_lte
  ]
)

There's more to it as you have to have a filterrific form in your view which returns the parameters for your scopes and an index.js.erb view which updates your list of cities, but this should help you get a little further.