Question

I’m fairly new to Ruby on Rails and within my app the user is able to create a ‘build’ record that will only be saved if the entire record is unique. If a user tries to create an existing ‘build’ / record and the validation fails, I need to be able to redirect that user to the existing record.

As I have stated, I am a novice and made a valiant attempt at using the parameters passed to my create action as so:

    def create

    @build = Build.new(params[:build])

    if @build.save
        redirect_to :action => 'view', :id => @build.id 
    else
        @bexist = Build.find(params[:build])
        redirect_to :action => 'view', :id => @bexist.id
    end

end

Clearly this isn’t correct… I also tried to look into callbacks with after_validation, but wasn’t sure how to access or even store the existing record’s id. Anyone have any suggestions?

Answer 1

You need the attribute/value hash to be passed as the :conditions option, and you need to specify :first, :last, or :all as the first argument.

@bexist = Build.find(:first, :conditions => params[:build])

Alternatively, you can use the #first method instead of using #find with a :first argument.

@bexist = Build.first(:conditions => params[:build])

In Rails 3, you have yet another option…

@bexist = Build.where(params[:build]).first