scope with multiple arguments

[btazi]

My issue is fairly simple, in my app I have this scope that retrieves all the courses within a certain distance with the help of a postgis database:
scope :with_distance, -> (lat, lng, distance_in_meters) {...}
The scope is working but I don't know how to write the select options for a scope that has more than one argument. I wrote this huge mess that's not even working (wrong number of arguments) but you get the idea:
[ [['2 km'], [current_user.lat, current_user.lng, 2000]], [['5 km'], [current_user.lat, current_user.lng, 5000]] ]
I've been trying to solve this for a long time, any suggestion would be greatly appreciated

[jhund]

@spawnge it looks like the lat and lng params are attributes of the current_user. So you don't need to include them in the select options. Why don't you just store them in two hidden form fields? Then your select options contain just the various distances:

# select options, set in controller:
[['2 km', 2000], ['5 km', 5000], ...]

# nested form field in view:
<%= f.fields_for :with_distance do |with_distance_fields| %>
  <%= with_distance_fields.hidden_field :lat, value: current_user.lat %>
  <%= with_distance_fields.hidden_field :lng, value: current_user.lng %>
  <%= with_distance_fields.select :distance_in_meters, @filterrific.select_options[:with_distance] %>
<% end %>

Instead of overriding the value in the form, you could also initialize the @filterrific object in the controller with the user's position params.

See issue #27 for more info.

[btazi]

Hi @jhund thanks a lot for your answer. I tried to implement your solution but it doesn't seem to work with the scope I have (that I copied from this tutorial) Can you take a quick look at it ?

  scope :with_distance,  -> (lat, lng, distance_in_meters) {
  where(%{
    ST_DWithin(
      ST_GeographyFromText(
        'SRID=4326;POINT(' || courses.lng || ' ' || courses.lat || ')'
      ),
      ST_GeographyFromText('SRID=4326;POINT(%f %f)'),
      %d
    )
  } % [lng, lat, distance_in_meters])
}

Or how can I initialize the @filterrific object with the user's position params? Sorry for all these questions I'm still a beginner :)

[jhund]

@spawnge here is what I would do:

In the model the with_distance_attrs are passed as a single hash, so you need to change the parameters for the scope:

scope :with_distance,  -> (with_distance_attrs) {
  ['lng' => '-123', 'lat' => '49', 'distance_in_meters' => '2000']
  where(%{
    ST_DWithin(
      ST_GeographyFromText(
        'SRID=4326;POINT(' || courses.lng || ' ' || courses.lat || ')'
      ),
      ST_GeographyFromText('SRID=4326;POINT(%f %f)'),
      %d
    )
  } % [with_distance_attrs['lng'], with_distance_attrs['lat'], with_distance_attrs['distance_in_meters']])
}

Then the form looks like this. I assign values for lat and lng directly from current_user, rather than initializing the @filterrific object with it:

<%= f.fields_for :with_distance do |with_distance_fields| %>
  <%= with_distance_fields.hidden_field :lat, value: current_user.lat %>
  <%= with_distance_fields.hidden_field :lng, value: current_user.lng %>
  <%= with_distance_fields.select :distance_in_meters, @filterrific.select_options[:with_distance] %>
<% end %>

So the only difference to what you have posted is that the with_distance scope receives a single argument, rather than three.