Category: Ruby on Rails

Re-Index Sunspot/Solr – Ruby on Rails

Just a very quick post on how to re-index Sunspot/Solr – simply open the console and enter the following command:

chris@chris-VirtualBox:~/site$ rake sunspot:solr:reindex

WARNING: 'task :t, arg, :needs => [deps]' is deprecated.  Please use 'task :t, [args] => [deps]' instead.
    at /usr/lib/ruby/gems/1.8/gems/sunspot_rails-1.2.1/lib/sunspot/rails/tasks.rb:41
chris@chris-VirtualBox:~/site$

That’s all there is to it, nice and easy!

Will_Paginate with Sunspot – Ruby on Rails

Hey all,

I’ve just gone through setting up will_paginate with sunspot 1.3, just thought I’d share in case anyone else has any troubles/improvements.

In my case I’m setting it up on a products model.

  #products.rb

  #Sunspot/Search
  searchable do
    text :title, :boost => 5
    text :description
  end


#products_controller.rb
  #Products search
  def search

    #Create vars
    search = Product.search do
      fulltext params[:search]
      paginate :page => params[:page] || 1, :per_page => 2
    end    

    #Retrieve results
    @products = search.results

    #Create responses
    respond_to do |format|
      format.html { render 'index' }
    end
  end


#Search partial - _search.html.erb
 'products', :action => 'search', :method => :get do %>
    '25', :class => 'search' %>



#Product display page - index.html.erb

    "products/product_line", :locals => {:product => product} %>

      
 false, :params => { :search_text => params[:search_text] } %>

Well that’s about it, if anyone needs any further info or has any tips, leave a comment and I’ll get back to you asap.

Uninstalling a Gem – Ruby on Rails

Due to a few recent issues with SunSpot (see my previous posts), I’ve decided to uninstall it until I have enough time to work on it properly. Once again, Ruby makes this pretty simple:


chris@chris-VirtualBox:~/site$ sudo gem uninstall sunspot
[sudo] password for chris: 

You have requested to uninstall the gem: sunspot-1.2.1 sunspot_rails-1.2.1 depends on [sunspot (= 1.2.1)]
If you remove this gems, one or more dependencies will not be met.
Continue with Uninstall? [Yn]  y


Remove executables: sunspot-solr, sunspot-installer in addition to the gem? [Yn]  y


Removing sunspot-solr
Removing sunspot-installer


Successfully uninstalled sunspot-1.2.1

ActiveRecord::HasManyThroughAssociation NotFoundError – Ruby on Rails

I ran into a bit of a problem with a has_many relationship in rails today:

ActiveRecord::HasManyThroughAssociationNotFoundError in FeedbacksController#index
…
Could not find the association :sub_orders in model User

This turned out to be a fairly simple fix, I had forgotten to add a has_many relationship before adding the has_many :through => x relationship. There is a fairly detailed explanation on StackOverflow for anyone who is curious.

undefined method `to_sym’ for nil:NilClass – Ruby on Rails Migration

While trying to do a migration today I received the following message:

undefined method `to_sym’ for nil:NilClass

#After running a trace (rake db:migrate –trace)
undefined method `to_sym’ for nil:NilClass
/usr/lib/ruby/gems/1.8/gems/activesupport-3.1.1/lib/active_support/whiny_nil.rb:48:in `method_missing’
…

This was the migration:

class AddDefaultValuesToFeedbacks  0
    change_column :stores, :rating, :decimal, :precision => 8, :scale => 2, :default => 0
  end
end

Unfortunately this problem also prevented me from performing any other migrations on the table. I attempted deleting all relevant migration files and then re-running them, restarting the server and rolling back to a previous migration – none of which worked.

Eventually I resorted to exporting the dataset, dropping the table via sqlite3 and recreating it. Thankfully this seems to have worked. The only hint I’ve come across that may explain the cause of this problem, other than typos or referring to non-existant columns, is that it can occur if a migration is screwed over before it finishes and fails to rollback properly.

If anyone else has any concrete answers, please let me know in the comments!

Debugging with Exceptions – Ruby on Rails

Ran into a bit of trouble with a model today, after a bit of a google I came across this technique which helped me solve it:

#Raise exception on object.inspect
raise Object.inspect

#Example 1
raise order.inspect

#Example 2
raise [sub_orders.count].inspect

This simply allows you display variable values as an exception. By placing a few of these throughout your troublesome code you can simulate a fully targeted trace.

Submit form_for to Custom Action – Ruby on Rails

Just another quick problem I ran into with rails this afternoon – how to submit a form_for to a custom action. Luckily there’s quite a bit on how to do this in the documentation, my solution ended up as follows:

 url_for(:controller => 'feedbacks', :action => 'leave_seller_feedback') do |f| %>

Just substitute your form_for tag with the one above and put in the relevant details and it should all work fine. Keep in mind that the submit tag doesn’t need to be changed, just the form_for tag.

Flash Notice Appearing Twice – Ruby on Rails

Ran into another flash notice issue, my messages were not disappearing after the first view. My code was as follows:

#Create flash warning
flash[:warning] = ("This product has been replaced: " +new_product.title + "").html_safe

It turns out that all you have to do to fix this issue is the following:

flash.now[:warning] = ("This product has been replaced: " +new_product.title + "").html_safe

This blog gives a brief overview of when to use flash.now[notice] and when to use flash[:notice]. A basic rule of thumb is that if you’re using a redirect, use flash[:notice], if you’re simply rendering a view, use flash.now[:notice].

Validating Boolean Value of False in Rails

I came across a bit of a weird one this afternoon when trying to validate. Several of my fields appeared to be incorrectly flagged as not having a value.

This is the validation I was using:

#Define validation
validates :order_id, :user_id, :acknowledged, :completed, :presence => true

 

The fields that were flagging as not present were :acknowledged and completed. After hardcoding the values and still not getting anywhere I realised that while values were being provided, they were boolean values of false. Apparently :presence will treat a value of false as not being present.

After another Google search I came across this post which shows how to validate a boolean value.

When implemented within my app, the new validation looks like this:

#Define validation
validates :order_id, :user_id, :presence => true
validates :acknowledged, :completed, :inclusion => {:in => [true, false]}

Hopefully that’ll be able to help a few of you out as well.

Errno::ECONNREFUSED in – Ruby on Rails

First problem of the morning – Errno::ECONNREFUSED in ProductsController#create. This one was actually a little bit tricky – for me anyway. The error seemed to imply a database issue, so I started by checking all the common problems there however no luck unfortunately.

After a bit of a Google I came across a post mentioning that a few people had encountered this after installing Solr. I had previously setup Sunspot, which just so happens to sit on top of Solr.

Manually starting solr fixed the problem – just using the code below:

chris@chris-VirtualBox:~/site$ rake sunspot:solr:start

 

I’m not really sure what triggered the error as I’d been using the exact same functionality all morning without any changes or issues. Thankfully it’s a quick fix. If anyone has anymore info on the problem please let me know.

Anyway, that’s all I’ve got for you for now, Good Luck!

UPDATE: I had this problem again this morning and realised that it was the models with search fields still defined that were triggering the error. Removing this code seems to have completely resolved the issue.