?
Solved

You have a nil object when you didn't expect it!

Posted on 2009-05-18
2
Medium Priority
?
523 Views
Last Modified: 2013-11-13
Have a look at the code below and see if you can point me in the right direction...I'm certain it is something fundamental.
in my controller file:
 
require "RubyGems"
require "feed_tools"
		
def user_data
      @feed = FeedTools::Feed.open(params[:feed_url])
      # You can first test it with a static feed url like this
      @feed = FeedTools::Feed.open('http://www.sphred.com/combined_feed')
end
 
 
Error in browser:
 
You have a nil object when you didn't expect it!
The error occurred while evaluating nil.link
 
Extracted source (around line #105):
 
102: 	  
103: 	  <div>
104:     <h3>
105:       <a href="<%= h @feed.link %>">
106:       <%= @feed.title %></a>
107:     </h3>
108:     <p><%= @feed.description %></p>

Open in new window

0
Comment
Question by:envythe
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 12

Accepted Solution

by:
cminear earned 500 total points
ID: 24416071
The long and short of it is that @feed is either not being set, or being set to nil, and thus trying to apply the 'link' method to a nil doesn't work.  However, I'm actually surprised you are seeing the error that you are.  Based on my quick tests, I would expect you to be seeing Exceptions being thrown by either of the "FeedTools::Feed.open" calls you gave.  

Just using IRB, I try:
  feed = FeedTools::Feed.open(nil)
I get this exception.
  NoMethodError: undefined method `scheme' for nil:NilClass
So if you called the 'user_data' action with no 'feed_url' parameter passed in, that should have thrown an exception.

If you did pass in a 'feed_url' parameter, then going to the next line, I tried:
  feed = FeedTools::Feed.open('http://www.sphred.com/combined_feed')
I get this exception:
  FeedTools::FeedAccessError: Socket error prevented feed retrieval
'www.sphred.com' does not exist (at least not from where I'm doing web and DNS requests).

So the only explanation that would account for what you are seeing is that your environment has some sort of global 'rescue' applied to the controller methods, but at the same time, the 'rescue' doesn't apply to the rendering of the page.  Are you not sharing some part of your code with us?
0
 

Author Closing Comment

by:envythe
ID: 31583667
Appreciate the help - was able to work through it with your comments
0

Featured Post

Hire Technology Freelancers with Gigs

Work with freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely, and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: narshlob
If you've ever programmed in Ruby and have come across either a proc or a lambda, you might have been wondering what the difference is between the two and when you would use one over the other. This article will try to explain the difference between…
Recently I spent hours debugging an issue in a Rails project where ActiveRecord was causing MySQL errors trying to create a User object of a class at the top level of a Single Table Inheritance model structure.  It turns out `.create` behaves differ…
This is my first video review of Microsoft Bookings, I will be doing a part two with a bit more information, but wanted to get this out to you folks.
Have you created a query with information for a calendar? ... and then, abra-cadabra, the calendar is done?! I am going to show you how to make that happen. Visualize your data!  ... really see it To use the code to create a calendar from a q…
Suggested Courses
Course of the Month7 days, 23 hours left to enroll

765 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question