Question

I’m using the following to enable users to sort comments by date (ASC), date (DESC) and vote:

posts_controller.rb:

  def show
    @post = Post.find(params[:id])
    @comments = @post.comments.paginate(:page => params[:page],
                                        :per_page => 5).order(params[:order_by])
    @comment = @post.comments.build
  end

views/posts/show.html.erb:

<div class="comments-tabs">
  <span><%= link_to 'Votes', post_path(@post, :order_by => "total_votes DESC") %></span>
  <span><%= link_to 'Date (ASC)', post_path(@post, :order_by => "created_at ASC") %></span>
  <span><%= link_to 'Date (DESC)', post_path(@post, :order_by => "created_at DESC") %></span>
</div>

the URL ends up looking like this:

http://localhost:3000/posts/59?order_by=total_votes+DESC
http://localhost:3000/posts/59?order_by=created_at+ASC
http://localhost:3000/posts/59?order_by=created_at+DESC

I would like to create an if statement to add a class to the current tab. For example:

    http://localhost:3000/posts/59?order_by=created_at+ASC


  <span class="comment-tab"><%= link_to 'Votes', post_path(@post, :order_by => "total_votes DESC") %></span>
  <span class="comment-tab current"><%= link_to 'Date (ASC)', post_path(@post, :order_by => "created_at ASC") %></span>
  <span class="comment-tab><%= link_to 'Date (DESC)', post_path(@post, :order_by => "created_at DESC") %></span>

Answer 1

You can use the current_page? method to determine whether the user is viewing a certain page and apply an html class based on that.

Here’s an example:

 %ul
    %li{:class => "#{current_page?(root_path) ? "selected" : ""}"}= link_to content_tag(:span, "Home"), root_path
    %li{:class => "#{current_page?(birth_certificate_path) ? "selected" : ""}"}= link_to content_tag(:span, "Birth Certificates"), birth_certificate_path
    %li{:class => "#{current_page?(marriage_certificate_path) ? "selected" : ""}"}= link_to content_tag(:span, "Marriage Certificates"), marriage_certificate_path
    %li{:class => "#{current_page?(death_certificate_path) ? "selected" : ""}"}= link_to content_tag(:span, "Death Certificates"), death_certificate_path