ruby - Rails + Nokogiri : controller create -

i creating simple_form allows users create new article in database providing link original article. if user provides url ("original_url"), use nokogiri fetch information.

i following error message: "no implicit conversion of nil string", tells me simple_form input field "original_url" not available used in controller / nokogiri.

is possible use variable simple_form before saving it?

my controller - create code:

def create   if @original_url = nil     @article = article.new(article_params)   else     @url = params[:original_url] #### think problem is. how pass "original_url" input controller? ####     data = nokogiri::html(open(@url))     headline = data.at_css(".entry-title").text.strip     @article = article.new(:headline => headline)   end    respond_to |format|     if @article.save       format.html { redirect_to @article, notice: 'article created.' }       format.json { render :show, status: :created, location: @article }     else       format.html { render :new }       format.json { render json: @article.errors, status: :unprocessable_entity }     end   end end 

should call "original_url" variable in way?

first, use assignment in first condition:

if @original_url = nil 

so @original_url becomes nil , condition never true. that's classic mistake.

that's how check nil in ruby:

if @original_url.nil? 

now, reason why @url nil in params, have article root. in case, need write:

@url = params[:acticle][:original_url]