Question

Alright. First off, I am new to Rails and this is the first project I am trying to build from scratch.

I have 2 models: Course and Question. I want to be able to add Questions to a specific Course, so Course is the parent model of Question. (Course has_many :questions and Question belongs_to :course)

From courses/show I render a partial:

<%= render 'questions/form', :question => @course.questions.build %>

and the partial questions/_form:

<%= form_for(question) do |f| %>
  <div class="field">
    <%= f.text_field :content %>
    <%= f.hidden_field :course_id %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

and here is the create function:

def create
    @course = Course.find(params[:question][:course_id])
    question = @course.questions.build      
    if question.save
      redirect_to @course
    end   
end

But in my console I get the following output:

Started POST "/questions" for 127.0.0.1 at 2011-10-27 19:06:25 -0400
  Processing by QuestionsController#create as HTML
  Parameters: {"utf8"=>"✓",         "authenticity_token"=>"negkm0uXBez8sisXl3pFVgfvhcDkixFPiMjzM68mNVU=", "question"=>{"content"=>"hallo", "course_id"=>"2"}, "commit"=>"Create Question"}
  Course Load (0.3ms)  SELECT "courses".* FROM "courses" WHERE "courses"."id" = $1 LIMIT 1  [["id", "2"]]
  (0.3ms)  BEGIN
  SQL (0.5ms)  INSERT INTO "questions" ("content", "course_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id"  [["content", nil], ["course_id", 2], ["created_at", Thu, 27 Oct 2011 23:06:25 UTC +00:00], ["updated_at", Thu, 27 Oct 2011 23:06:25 UTC +00:00]]
  (1.6ms)  COMMIT

What I don’t understand is that the Parameters include “content”=>”hallo”, but the value inserted into my table is nil…

I am fairly sure that I made a jumbled up mess because this is the product of an hour or trial and error, if anyone has a small change I should make or even a completely different way to achieve the same goal, that would be much appreciated.

Answer 1

You are looking up a course with a course_id, if one exists, but you make no further references to the params hash-like object, nor the content parameter within params — so it can never be saved. Try:

question = @course.questions.build(params[:content])