creating an object with has_many association results in NoMethodError

Question

Controllers

class ExperiencesController < ApplicationController
  def create
    @resume = Resume.find(params[:resume])
    @experience = @resume.build_experience(params[:experience])
  end
end

class ResumesController < ApplicationController
  def create
    @resume = Resume.new(params[:resume])
    @resume.build_webconnection
    @resume.build_experience   # <<<<<<<<< Error occurs here

    if @resume.save
      #UserMailer.created_resume_email(@user).deliver
      redirect_to @resume
    else
      @title = "Create a new resume"
      render :action => "new"
    end
  end
end

Models

class Experience < ActiveRecord::Base
  belongs_to :resume
end

class Resume < ActiveRecord::Base
  has_one   :webconnection
  has_many  :experiences
end

Error Message when I try to create a Resume (which also creates an Experience associated with Resume)

NoMethodError in ResumesController#create
undefined method `build_experience' for #<Resume:0xbb428a4>

I feel like I have everything pretty much in place, but missing an 's' or something somewhere. Any idea why I'm getting this error?

Answer 1

You would normally use build_experience when using a has_one or a belongs_to association. It's working for webconnection because it is a has_one association.

There's a difference with has_many associations though: you must call the build method on the association, like this: resume.experiences.build. This indicates

Because this is a has_many association and not a has_one or a belongs_to, you should be using resume.experiences.build.