Problems with rails helper link_to concerning class - css

Question

I'm having difficulties with rails. In fact, I wrote these lines :
<%= link_to :controller => "offers", :action => "get_offer", :offer_slug => offer.friendly_id, {:class => "media"} do %>
.
.
.
<% end %>
My problem is that everything that is inside link_to is getting the css effects of a hyperlink (no padding, gets underlined when hover), instead of custom properties.
It's like the :class property isn't being taken into account.
Just in case, here's the full part :
<<%= link_to :controller => "offers", :action => "get_offer", :offer_slug => offer.friendly_id, {:class => "media"} do %>
<li id="<%= offer.id %>" class="media" style="border: 1px solid #696969">
<div class="col-lg-3" style="margin-bottom:0px; font-size:12px; text-align:center; margin-right:10px;">
<% if offer.subcategory.nil? %>
<img class="media-object" src="<%= asset_path "other-icon.png" %>" style="margin-bottom:5px;">
<% elsif offer.subcategory.category.icon.empty? %>
<% else %>
<img src="<%= asset_path offer.subcategory.category.icon %>" style="margin-bottom:5px; width:110px;">
<% end %>
<br/>
<% if offer.subcategory.present? %>
<b><%= offer.subcategory.category.name %></b><br/> <%= offer.subcategory.name %>
<% else %>
<b>Autres</b><br/> <%= offer.subcategory_other %>
<% end %>
</div>
<div class="media-body">
<!--Titre annonce + type contrat-->
<div style="text-align:right; margin-bottom: 10px;">
<% if offer.id >= #new_limit %>
<span class="label label-warning">New</span>
<% end %>
<span class="label label-success"><%= (offer.max_price * 0.85).ceil %> euros</span>
<span class="label label-success" style="background-color: grey"><%= (offer.customer_objective) %>
succès </span>
</div>
<h4 class="media-heading">
<%= raw(offer.name) %>
</h4>
<p>
<% if offer.description %>
<%= offer.description.split[0..60].join(" ") %>
<% if offer.description.split[0..60].count >= 59 %>
<% end %>
<% end %>
</p>
<% if offer.company_context.present? %>
<p>
<%= offer.company_context.split[0..60].join(" ") %>
<% if offer.company_context.split[0..60].count >= 59 %>
<% end %>
</p>
<% end %>
</div>
<div class="offer-tags">
<% offer.offer_tags.each do |offer_tag| %>
<span class="badge"><%= offer_tag.tag.name %></span>
<% end %>
</div>
</li>
<% end %>

Answer 1

Try to wrap the class in curly braces:
<%= link_to :controller => "offers", :action => "get_offer", :offer_slug => offer.friendly_id, { :class => "media" } %>
The Rails link_to helper is pretty flexible and allows a few different call signatures, which can lead to confusion. You are needing this one:
link_to(body, url_options = {}, html_options = {})
Without the wrapping braces, Rails is not clear that :class is in fact an HTML option.
Docs here. I should mention I also dropped your trailing do which implied a block that didn't seem to be there (nor was it needed).
UPDATE
I did not understand that the block was intended as the link body. In that case, the right call signature would be:
link_to(options = {}, html_options = {}) do
# name
end
So, your body is fine, but in your link_to, you want to group the URL options, followed by the HTML options. Plus I think you may need parentheses around the whole call for it to work correctly:
<%= link_to({ :controller => "offers", :action => "get_offer", :offer_slug => offer.friendly_id }, { :class => "media" }) do %>