How to use call method from Model to controller in Rails

Question

I am fairly new to rails and currently working on the functionality of my personal project where I have multiple models. I have these models - Places, Favorites, ThingsToDo, User.

User, ThingsToDo, and Favorites have a many-many relationship where Favorites is a join table. /places (PlacesController) renders all the places as of now. I am trying to render cities that have the most favorites across all their things_to_do should be shown first followed by the next places that are not added by as favorites in user's account.

Note(places and things_to_do have has_many associations).

Favorite Model - group_by_favorite(method name)

class Favorite < ApplicationRecord
  belongs_to :user
  belongs_to :things_to_do
end

#validates :things_to_do_id, uniqueness: { scope: :user_id, :message => "has already been added as favorite" }

def group_by_favorite
  Favorite.joins(:things_to_do,:user).group(:place_id).count
end 

Place Model

    has_many :things_to_dos
end

def self.top_places
 @places_render = group_by_favorite.sort
end

Place Controller

class PlacesController < ApplicationController

    def index
        @places_render = top_places()
        places = Place.all 
        render json: places
    end

When I am trying to run /places route, I am getting this error

"#<NoMethodError: undefined method `top_places' for #<PlacesController:0x00000000011aa8>>",

My React Code for /places

export default function DestinationContainer({user}){

    const[allDestination,setAllDestination]= useState([])
    const [search, setSearch] = useState("");
   
    
    useEffect(()=> {
        fetch("/places")
        .then((res) => res.json())
        .then((data) => {
          
            setAllDestination(data)
        })
    },[])

    

    const filterPlaces = allDestination.filter(
        (destinations) =>
        destinations.city.toLowerCase().includes(search.toLowerCase()) )


    return (
        <> 
            <Switch> 
             <Route exact path= "/places">
                <SearchPlace search={search} setSearch={setSearch}/>
                <DestinationView allDestination= {filterPlaces} user = {user} />
             </Route>
             <Route path="/places/:destinations" >
                <ThingsToDoRender user ={user} /> 
             </Route>
             </Switch> 
        </>
    )
}

Is there a way that I can fix this error?I also tried to use scope but not sure if it is applicable in this case.

Answer 1

As your error says, the method top_places() is not defined in your PlacesController class. But it is a Place class function. So try the following:

@places_render = Place.top_places()