Couldn't find ArticlesSkill with ID=1 for Article with ID= - ruby-on-rails

Question

I am trying to create an article.
class Article < ActiveRecord::Base
belongs_to :article_skill
attr_accessible :articles_skill_attributes
accepts_nested_attributes_for :articles_skill
end
class ArticlesSkill < ActiveRecord::Base
attr_accessible :description, :name
has_many :articles
end
This is my form in the article/new.html.erb
<%= article_form.fields_for :articles_skill, #article.articles_skill do |b|%>
<label class="medium"><span class="red">*</span> Skill</label>
<%= b.select :id, options_for_select(ArticlesSkill.all.collect{|m| [m.name, m.id]}) %>
<%end%>
Here the article_form is the builder for the #article form object.
If I try to save the #article object its showing this error.
Couldn't find ArticlesSkill with ID=1 for Article with ID=

Answer 1

I've been struggling with this problem for a few days. Did a lot of searching.. it took going to the rails console and searching by the exception being thrown instead to make any progress with this.
Check out this answer on this question for why it's happening, and possible workarounds.
Use rails nested model to *create* outer object and simultaneously *edit* existing nested object?
Be aware that using the first option presented here creates a security hole as described in http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2010-3933

Answer 2

The second parameter in your fields_for call seems unnecessary. ActiveRecord is performing a lookup on the association articles_skill for #article when it reaches that param, but since the #article is new and has yet to be saved, it has no ID and triggers an error.
<%= article_form.fields_for :articles_skill do |b|%>
<label class="medium"><span class="red">*</span> Skill</label>
<%= b.select :id, options_for_select(ArticlesSkill.all.collect{|m| [m.name, m.id]}) %>
<% end %>

Answer 3

I can suggest only a workaround. It works, but I don't like it - I want some out-of-the-box solution.
I assume you have a function:
def articles_skill_params
params.require(:articles_skill).permit(:description, :name,
article_attributes: []) end
Add a function
def articles_skill_params2
params.require(:articles_skill).permit(:description, :name)
end
Add another function:
def set_article
article_id = articles_skill_params[:article_attributes][:id]
article = Article.find(article_id)
#articles_skill.articles << article
#articles_skill.save
end
Change your ArticlesSkillController#create:
def create
#articles_skill = ArticlesSkill.new(articles_skill_params2)
set_article
respond_to do |format|
if #articles_skill.save
format.html { redirect_to #articles_skill, notice: 'Article skill was successfully created.' }
format.json { render :show, status: :created, location: #articles_skill }
else
format.html { render :new }
format.json { render json: #articles_skill.errors, status: :unprocessable_entity }
end
end
end
As you can see, we simply exclude the nested attributes from the parent object creation (thus eliminating the error), then manually add them later.

Answer 4

If you just want people to be able to select an existing skill you don't need nested attributes at all (that's useful for when you might want people to be able to create an article skill from the same form that creates an article). You just want to set article_skill_id to an existing value, so you can just do
<%= form_for(#article) do |f| %>
...
<label class="medium"><span class="red">*</span> Skill</label>
<%= f.select :article_skill_id, ArticlesSkill.all.collect{|m| [m.name, m.id]}) %>
<% end %>