Raise helpful error

Point user at installation instructions if data not found.
joecorcoran · Oct 29, 2013 · 7201f8c · 7201f8c
1 parent e58296b
commit 7201f8c
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/lib/cities/city.rb b/lib/cities/city.rb
@@ -65,10 +65,16 @@ def has_data?
       end
 
       def path_for_country(code)
-        raise unless has_data?
+        raise DataNotFound.new unless has_data?
         File.join(data_path, "#{code}.json")
       end
 
   end
 
+  class DataNotFound < StandardError
+    def message
+      'JSON data not found. See README.md for installation instructions.'
+    end
+  end
+
 end