Hey guys,
I had recently a very weird experience. I have a Loader class that run’s a lot of different things on Active Record objects. One thing this loader does, is to preload data based on each classes settings. so basically:
scope.preload(preloads)
scope has a collection of Active Record objects.
preloads has an array with hashes inside that show what information to preload for each relation.
Preloads use to be a function inside the loader class that calculated that array, but it needed some information of the class itself, so I refactored it out into another class.
This is an example how the code works, the implementation is not very important and I simplified it for the sake of the example:
Class Incident
def preloads
calculate preloads
end
def load
Loader.new(preloads)
end
end
Class Loader < Struct.new(:preloads)
def initialize(opts = {})
self.preloads = opts[:preloads] ||
end
def load
scope.preload(preloads)
end
end
So before the preloads when inside of the loader class return something like(Every key is a symbol):
[{:updated_by_user=>}, {:service=>[{:account=>:additional_fields}, {:service_customers=>{:customer=>}}]}, {:owner=>}, {:closed_by_user=>}, {:assigned_user=>}, {:beetil=>{:satisfaction_ratings=>}}, {:beetil=>{:additional_values=>:additional_field}}, {:beetil=>{:additional_values=>:additional_field}}, :priority, :priority, :service_activity_type, {:beetil=>{:customer_beetils=>{:customer=>}}}, {:beetil=>:audit_trail_groups}, {:beetil=>:latest_audit_trail_group}, :incident_status, :received_by_user, {}, {}]
And when passed as an argument is transformed into(Every key is a string):
[{“updated_by_user”=>}, {“service”=>[{“account”=>:additional_fields}, {“service_customers”=>{“customer”=>}}]}, {“owner”=>}, {“closed_by_user”=>}, {“assigned_user”=>}, {“beetil”=>{“satisfaction_ratings”=>}}, {“beetil”=>{“additional_values”=>:additional_field}}, {“beetil”=>{“additional_values”=>:additional_field}}, :priority, :priority, :service_activity_type, {“beetil”=>{“customer_beetils”=>{“customer”=>}}}, {“beetil”=>:audit_trail_groups}, {“beetil”=>:latest_audit_trail_group}, :incident_status, :received_by_user, {}, {}]
But the problem is then I get an error of the load function saying:
TypeError: Cannot visit String
After I googled a little bit and debugged I realized that it worked with the keys as symbols and not as strings.
How weird is that? so load only accepts keys with symbols and not strings? is this a rails bug? am I approaching this wrong?
Any input would be appreciated.
all the best,
Andre
