title: Rails: param is missing or the value is empty: article
body: <p>I am new with Rails and I began to make a web app following the rubyonrails.org tutorial.</p>
  
  <p>My app is a blog with articles.. I implemented create and edit functions which worked pretty well but suddenly an error while trying to access <code>http://localhost:3000/articles/2/edit</code> in order to edit an article.
  The error is <code>ActionController::ParameterMissing in ArticlesController#edit param is missing or the value is empty: articles</code></p>
  
  <p>Here is my ruby code:</p>
  
  <p>class ArticlesController &lt; ApplicationController
      def index
          @articles = Article.all
      end</p>
  
  <pre><code>def new
      @article = Article.new
  end
  
  def edit
      @article = Article.find(params[:id])
      if @article.update(article_params)
          redirect_to @article
      else
          render 'edit'
      end
  end
  
  def show
      @article = Article.find(params[:id])
  end
  
  def create
      @article = Article.new(article_params)
      if @article.save
          redirect_to @article
      else
          render 'new'
      end
  end
  
  private
      def article_params
          params.require(:article).permit(:title, :text)
      end
  end
  </code></pre>
  
  <p>The line targeted by the error alert is <code>params.require(:articles).permit(:title, :text)</code>
  I really don't know where the error can be because everything was ok 2 minutes ago...</p>
  
  <p>Thank you for your help</p>