Question

Sorry for the newbie question but still very new to Ruby and Mongo.
Not 100% sure what I am missing, but how would I get just the value back
from “url” in the following json result?

[{"url":"www.google.com"}]

So I want something like if I do a

puts url_var 

it should just display http://www.google.com

MongoMapper code to get URl from Mongo

redirect_url = Surl.all(:url_key => "#{urlkey}") 
myjson = redirect_url.to_json(:only => [:url])
puts redirect_url

gives me

[{"url":"www.google.com"}]

if I do something like

redirect_url.each do |key,value|
  puts key
  puts value
end

key is still the full json string and value is empty.

Surely I must be missing something really basic here

Answer 1

Okay, I assume Surl is a model of yours, which has at least these fields url_key and url, so to access the url you don’t have to convert the result to json and then fetch to key, but you can access it directly.

Surl.all returns an array (check the mongo mapper docs), if you want a single result use Surl.find_by_url_key(urlkey). Now you can access the url directly by using puts redirect_url.url

redirect_url = Surl.find_by_url_key(urlkey)
puts redirect_url.url # => "www.google.com"

Be sure to read up on http://mongomapper.com/documentation/plugins/dynamic-querying.html and http://mongomapper.com/documentation/plugins/querying.html, to understand the results and differences.