rails, How to build table in helper using content_tag?

Question

Hi!

I defined function in application helper:

def display_standard_table(columns, collection = {})    
  content_tag :table do      
    concat content_tag :thead do
      content_tag :tr do
        concat columns.collect { |column| content_tag(:td, column[:display_name]) }
      end
    end      

    concat content_tag :tbody do
      collection.collect { |elem| 
        concat content_tag(:tr, columns.collect { |column|
          content_tag(:td, elem.attributes[column[:name]])
      })
    }
    end
  end
end

and I call it in my view:

<%= display_standard_table(
          [
            { :name => 'id', :display_name => 'Id' },
            { :name => 'login', :display_name => 'Login' },
            { :name => 'first_name', :display_name => 'Name' },
            { :name => 'last_name', :display_name => 'LastName' },
            { :name => 'email', :display_name => 'Email'}
          ], @users) %>

The output in html is:

<table><thead></thead><tbody></tbody></table>

and it should be:

<table><thead><tr><td>Id</td><td>Login</td>...</tr></thead><tbody><tr>row here</tr></tbody></table>

and i can't figure out what's missing. (btw. I'm using rails3)

[EDIT]

def display_standard_table(columns, collection = {})    
  content_tag(:table) do
    concat(content_tag(:thead) do
      concat(content_tag(:tr) do
        concat(columns.collect { |column| content_tag(:td, column[:display_name]) })
      end)
    end)

    concat(content_tag(:tbody) do
      concat(collection.collect { |elem|
        content_tag(:tr, columns.collect { |column|
          content_tag(:td, elem.attributes[column[:name]])
        })
      })
    end)
  end
end

The above version works ok but generated html is escaped :/ according to documentation strings produced by content_tag should be html_safe, but they're escaped :/

Answer 1

It's the missing concat in your :tr related content_tag.

Update

As for the escaping, take a look at the api docs for content_tag. You need to specify not to escape it. Of course, you'd be responsible for escaping the stuff inside the tags that you want escaped in that case.

Answer 2

See the railscast about that : http://railscasts.com/episodes/208-erb-blocks-in-rails-3 all is explain how you manage your block helper in rails 3