how to limit the number of location with rubygeocoder gem?

Question

I have a location object so location.nearbys get all the locations near location. But I want to limit the results to 5. That I am doing with location.nearbys.limit(5) , but the problem is when there are no nearby location I get an error message . It says limit cant be used on empty array []. So, what's the solution. I can use.

location = location.nearbys
location = location.nearbys.limit(5) unless location.empty?

Do I have better ways to do this ? I am using mongoid , rails 3.0.7 , ruby 1.9.2 .

Answer 1

This should work, even if you get an empty array.

location = location.nearbys
location = location[0..4]

Answer 2

The problem is that rubygeocoder returns a ActiveRecord::Relation if successful, but an empty Array on failure. And Ruby's Array does not respond to limit, so my tip is to use first(number) instead of limit(number), which will work with both results.

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Found out, that the best solution of this problem is to use take(5) which will work both on Mongoid::Criteria objects and Ruby Arrays.

Answer 3

I believe location.nearbys is a collection. You can impose the limit on collection itself as follows:

has_many locations, :limit => 5

In this way you retrieve only required data from the DB and also no hassle of rescue or try.

Answer 4

One way to write it would be location.nearbys.try(:limit, 5)

More on Object#try

Answer 5

Not sure if better - but alternatively you maybe be able to wrap it in a rescue block which would also give you the option on doing something else when the result is empty