Debug Error in Ruby script
I'm very new to Ruby. I have the following piece of code which is giving me an error.
class ItemsController < ApplicationController
def populate
Location.all.each { |l|
place = l.radar_place
next if !place
news_items = place.radars
news_items.each { |ni|
t = Lbs2.new
t.lat = l.lat
t.lng = l.lng
t.body = ni.body
t.save if !Lbs2.find_by_body(ni.body) 开发者_开发技巧#avoiding redundant news_items
}
}
render :text => "Success"
end
end
The error being shown when I hit the url is NoMethodError in ItemsController#populate undefined method `lat=' for Lbs2 id: nil, body: nil, created_at: nil, updated_at: nil
This code worked perfectly without "if !Lbs2.find_by_body(ni.body)" statement. When I included this, in order to avoid the redundant news_items, it gave me the above mentioned error. Can someone please tell me how to get rid of this error at the same time avoiding redundant news_items from getting populated in Lbs2? Thanks in advance
to avoid redundant items i think you can overwrite the validate()
method. something like the following:
def validate
conditions = {"lat" => self.lat, "lng" => self.lng}
if Lbs2.first(:conditions => conditions)
errors.add_to_base "Your error message"
end
end
OK, there are a few things going on here. The error message is saying that it doesn't know how to save something to the "lat" attribute of an Lbs2 object. Even though you told script/generate that you wanted a "lat" field for Lbs2, it looks like it didn't get saved after all. You can check db/schema.rb to be sure. But your first step will probably be to add that field to the appropriate table in the database. Read the Rails Migrations Guide for more info.
Also, there's a much better way to validate uniqueness of a field. In app/models/lbs2.rb
(assuming your Lbs2 object is defined there), add a line (outside of any methods) that says:
validates_uniqueness_of :body
Read the Rails Validations Guide for more info.
Hope this helps,
-Jeff T.
精彩评论