Generating a table in Ruby on Rails - ruby-on-rails

Question

Why doesn't this produce a table when called from my view? With fields_table(#user, ["id", "username"]) I am not getting the tbody's trs or tds, but I am getting everything else.
def fields_table(obj, fields)
return false if obj.nil?
content_tag(:table) do
thead = content_tag(:thead) do
content_tag(:tr) do
content_tag(:td, "Property") + content_tag(:td, "Value")
end
end
tbody = content_tag(:tbody) do
fields.each do |name|
content_tag(:tr) do
content_tag(:td, name) + content_tag(:td, obj.read_attribute(name))
end
end
end
thead + tbody
end
end

Answer 1

This code just iterates through the fields. It doesn't return anything, so the enclosing tbody isn't going to have anything to content.
tbody = content_tag(:tbody) do
fields.each do |name|
content_tag(:tr) do
content_tag(:td, name) + content_tag(:td, obj.read_attribute(name))
end
end
end
You need to return something like you do in the other parts of the code or change it to something like this:
tbody = content_tag(:tbody) do
fields.map do |name|
content_tag(:tr) do
content_tag(:td, name) + content_tag(:td, obj.read_attribute(name))
end
end.join
end

Answer 2

I would recommend rendering a partial using the collection argument, and built in rails goodness to do this type of operation. Im guessing you want the table headings to line up with the fields? You can still do that with something along the lines of the following (havent tested, but should work),
In your model define a class method or array as constant containing the attributes you want to display on the front end, e.g.
models/user.rb
VisibleFields = [:id, :username]
#workaround for toplevel class constant warning you may get
def self.visible_fields
User::VisibleFields
end
views/users/index.html.erb
<table>
<thead>
<tr>
<% User.visible_fields.each do |field| %>
<th><%= field.to_s.titleize %></th>
<% end %>
</tr>
</thead>
<tbody>
<%= render :partial => 'user', :collection => #users %>
</tbody>
</table>
**views/users/_user.html.erb**
<tr>
<% user.visible_fields.each do |field| %>
<td class="label"><%= field.to_s.titleize %></td><td class="value"><%= user.send(:field) %></td>
<% end %>
</tr>