In my rails app, I have two models, a ClientPage and a ContentSection, where ClientPage has_many :content_sections. I'm using the nested_form gem to both models to be edited with the same form. This works fine as long as the ClientPage has at least one ContentSection, but if there are no associated ClientSections, the using nested_form's link_to_add method throws the following NoMethodError:
undefined method `values_at' for nil:NilClass
The form is structured as follows:
<%= nested_form_for page, form_options do |f| %>
# ClientPage fields
# ClientSections
<%= f.link_to_add "Add new section", :content_sections %>
<% end %>
As long as there is at least one ClientSection associated with the page, this works fine. As soon as there isn't, the error is thrown. Removing the link_to_add also stops the error from being thrown. (There's actually a second nested model under ContentSection, and the same issue arises if there are no associated models.)
Not sure what I'm fairly obvious thing I'm missing, but any pointers or suggestions would be greatly appreciated.
Finally worked this out -- the error was due to the fact that I was using the gem in a slightly non-standard way. Within the form, instead of rendering all of the content sections the standard way:
<%= f.fields_for :content_sections do |section_form| %>
# section fields
<% end %>
I put it inside a loop, as I needed the index of each item (which is not stored within the model itself):
<% page.content_sections.each_with_index do |section, index| %>
<%= f.fields_for :content_sections, section do |section_form| %>
# section fields
<% end %>
<% end %>
The issue doing it this way is that the fields_for method does not get called if the association is empty, and as such the gem cannot build the blueprint for the object (which is used to add in the extra item when link_to_add is called).
The solution was to make sure fields_for got called even if the association was empty:
<% if page.content_sections.empty? %>
<%= f.fields_for :content_sections do |section_form| %>
# section fields
<% end %>
<% end %>
Related
I have a page that shows a list of events. When the event is clicked it takes you to a login page and it keeps the session id along with the page. When I go to the next page it always sends the last session variable.
<% #events.each do |e| %>
<%= link_to e.event_name, sessions_new_path %>
<%= e.event_start %> - <%= e.event_stop %>
<% session[:event_id] = e.id %>
<%= session[:event_id] %>
<br>
<% end %>
This shows the session[:event_id] is there and it is storing in the variable but when I click on the link it will send the last session[:event_id] of the loop. Any ideas would be helpful. I am looking at option of either passing the variable to the next page or storing it into a database cell, but not sure on how sessions are stored in databases.
Assuming you are using a supported database with ActiveRecord, you can configure your application to store sessions in the database by editing your_app/config/initializers/session_store.rb:
YourApp::Application.config.session_store :active_record_store
make sure to comment out or remove the line:
# YourApp::Application.config.session_store :cookie_store, :key => '_your_app_session'
Further, there are auth gems that handle redirecting users to protected pages after signing in. If you haven't already, look at Devise and/or authlogic. Personally, I prefer Devise.
I have a model called Note. Each note belongs_to :call_reason. And call_reason has_many :notes.
What I want to do in a view is display a list of call_reasons and a total count of each next to it so we can see what the most popular call reasons are.
Here's what I have so far:
dashboard_controller:
def index
#notes = Note.all
end
dashboard view:
<% #notes.each do |n| %>
<%= n.call_reason.reason %>
<% end %>
This lists all notes' call_reasons.
I'm stumbling on how to list each call_reason once with a total count next to it. What I have now just lists all the call_reasons per note which is a mess. I think I could scope this out somehow or change the instance variable but I'm having a hard time getting it right.
Any thoughts?
Since you want to list call reasons, you should start with that:
def index
#call_reasons = CallReason.all
end
Then in your view you can do this:
<% #call_reasons.each do |call_reason| %>
<%= call_reason.reason %> <%= call_reason.notes.count %>
<% end %>
Note that this will perform a query for every call reason in your database. To prevent this you can use a counter cache. Check out the section on counter cache on Rails Guides too.
I am using the cache-digests gem and following the instructions as per the Railscast, it creates and reads from a cache as you would expect, but the cache does not seem to be updating properly in relation to an associated record.
When moving a listing from one category to another, the category.live_entries count stays the same for the category I move it from, but goes up for the one I move it to.
So it sounds like I need a touch: all type method so it touches the one I am moving it from as well as the one it is moving to?
_category.html.erb
<% cache category do %>
<li>
<%= link_to category.name, category %>
<% if category.live_entries > 0 %>
(<%= category.live_entries %>)
<% end %>
- <%= category.desc %>
</li>
<% end %>
category.rb
class Category < ActiveRecord::Base
has_many :listings
def live_entries
listings.where(verified: true).count
end
end
listing.rb
class Listing < ActiveRecord::Base
belongs_to :category, touch: true
Any ideas on how to tackle this?
Guess I could create a before_update callback to touch the old category - but is there a better way?
Ok just adding this as an answer - but if anyone has a better solution please feel free to share.
I just added an after_update to touch the old category:
def touch_old_category(listing)
cat = listing.category_id_was
Category.find(cat).touch if cat
end
trying to make link to my recent uploaded image
<%= link_to (image_tag (post.image_url(:thumb))), post.image.url(:original), :class => 'postimage' %>
how ever it's not working, at all...
<% #post.image do |image| %>
<%= link_to (image_tag (post.image_url(:thumb))), post.image.url(:original), :class => 'postimage' %>
<% end %>
the fun part is that
<%= #post.image %>
works. but only shows /uploads/post/image/3/eKoh3.jpg
full code here https://gist.github.com/4332533
This line looks wrong to me:
<% #post.image do |image| %>
(btw your gist actually says #post.image.each do |image|, which I'm assuming is what you meant to do above)
If you are mounting an uploader on your Post model's :image attribute, then this makes no sense. A mounted uploader allows you to upload one image, and you can't iterate over it using each.
I'm not sure what you're trying to do. Are you trying to iterate over all the versions? Try post.image.versions.each
Are you trying to upload multiple images? Carrierwave can't help you with that directly. You'll need to create a new model, Image, and mount your uploader there. Your Post will need a line like
has_many :images
And your Image model will need to belong_to :post. You'll also need to figure out how to upload and manage images in that new table.
So I have two models & controllers. Projects and Designers.
In my designers index view, I want it to show a list of all the projects that the designer has.
However, when I do a simple query like this:
<% #projects.each do |project| %>
<tr>
<td><%= link_to 'Show', project %></td>
<td><%= link_to 'Edit', edit_project_path(project) %></td>
<td><%= link_to 'Destroy', project, :confirm => 'Are you sure?', :method => :delete %></td>
</tr>
<% end %>
From the index.html.erb in the Designers view, it gives me the following error:
NoMethodError in Designers#index
You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.each
However, when I run that EXACT code from the index.html.erb file in the projects view, it works perfectly.
So how am I able to access that controller or at least data from the view of another controller? Do I have to add a projects variable (where it queries the db) to my index object in my designers controller?
Thanks.
UPDATED TO USE A SINGLE DESIGNER RECORD
You should use associations. Add this to your models.
class Designer < ActiveRecord::Base
has_many :projects
end
class Project < ActiveRecord::Base
belongs_to :designer
end
Your view should look like this:
<% #designer.projects.each do |project| %>
<% end %>
More info on associations here:
http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html
Figured out one way to do it. All I had to do was add an instance variable in my designers controller:
#projects = Project.all
But...that's not very DRY. Does anyone have a more elegant 'DRY' solution, so if I want to access other variables in other controllers I can do that easily without having to re-create them in the current controller?
Thanks.
In your designers controller, you need to set the #projects instance variable to only those projects belonging to the signed in designer, correct?
You'll need something like this:
def index
#projects = Project.where(:user_id => where ever you've stored your userid)
end
I hope this helps.