how can I filter page content using multiple tags

I am newbie in rails and I want to filter my page content using muptiple tags. I am using act_as_taggable_on gem and I managed to have a tag-cloud and filter my content according tags. I used the following tutorial (http://railscasts.com/episodes/382-tagging). Now I couldn't manage to filter using multiple tag_types.

I added in my model/ article.rb the following code

acts_as_taggable
acts_as_taggable_on :assetType, :productType

in controller I don't know to write multiple tags . I tried the following way

def index
  if (params[:assetType] and params[:productType])
   @articles = Article.tagged_with(params[:assetType]).tagged_with(params[:productType])
  else
      @articles = Article.all
    end

  end

In my view in index.html.erb I have

<div id="tag_cloud">
  <% tag_cloud Article.productType_counts, %w[s m l] do |tag, css_class| %>
    <%= link_to tag.name, tag_path(tag.name), class: css_class %>
  <% end %>
</div>
<div id="tag_cloud_asset">
  <% tag_cloud Article.assetType_counts, %w[s m l] do |tag, css_class| %>
    <%= link_to tag.name, tag_path(tag.name), class: css_class %>
  <% end %>
</div>
<div class="article-content">  
  <% @articles.each do |article| %>    
      <h3><%= article.title %></h3>
      <p><%= article.content %></p>  

  <% end %>

and in my _form I have

<%= form_for(@article) do |f| %>
    <div class="field">
    <%= f.label :title %><br />
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :content %><br />
    <%= f.text_area :content %>
  </div>
  <div class="field">
    <%= f.label :assetType_list, "Tags (Asset Type separated by commas)" %><br />
    <%= f.text_field :assetType_list %>
    <%= f.label :productType_list, "Tags (Product Type separated by commas)" %><br />
    <%= f.text_field :productType_list %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>

Could someone help me how should I modilfy my controller, index and _form page? now it is showing all my posts and when I click on tags the content is not changed

Using this as a basic reference point:

https://github.com/mbleigh/acts-as-taggable-on#finding-tagged-objects

Try this:

def index
  tags = []
  tags << params[:assetType] unless params[:assetType].blank?
  tags << params[:productType] unless params[:productType].blank?

  if tags.count == 2
    @articles = Article.tagged_with(tags)
  else
    @articles = Article.all
  end
end

Adjustments:

• Checking each parameter for null and empty string using blank check. Perhaps it's possible that null and blank are the same in this context.
• Adding tags to an array, so that I can pass them all at once. Not just to simplify the call, but you can have more explicit control over the matching style by adding additional parameters to the call (such as match all or any tags).

Hope that helps, good luck!