Rails - Jul 2005 - Using a builder-like construct in a template?

I would like to write code roughly like this in a template

<% collapsible_fieldset(
     :legend => ''Address'',
     :except => ''new'',
     :valid => @address) do %>
  <%= render :partial => ''shared/address'', :object =>
@address %>
<% end %>

The nested code should work just as usual, but I want to wrap it in 

<fieldset ...>
  <legend>Address</legend>
  <!-- content -->
</fieldset>

The actual attribute values of the fieldset tag are intended to depend 
on the current action and on wether the address object is valid. 
Assuming these conditions are met, the start tag would look like this

<fieldset class="collapsible initiallycollapsed">

Which is picked up by some nicely unobtrusive script in the browser to 
collapse the fieldset to just its legend.

I''ve got all the individual pieces, but I don''t see how to
wrap them up
with some syntactic sugar as shown above.

Michael

-- 
Michael Schuerig                         Those people who smile a lot
mailto:michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org                          
Watch the eyes
http://www.schuerig.de/michael/    --Ani DiFranco, Outta Me, Onto You

On Jul 29, 2005, at 11:05 AM, Michael Schuerig wrote:
>
> I would like to write code roughly like this in a template
>
> <% collapsible_fieldset(
>      :legend => ''Address'',
>      :except => ''new'',
>      :valid => @address) do %>
>   <%= render :partial => ''shared/address'', :object
=> @address %>
> <% end %>
>
> The nested code should work just as usual, but I want to wrap it in
>
> <fieldset ...>
>   <legend>Address</legend>
>   <!-- content -->
> </fieldset>
>
<snip>
> I''ve got all the individual pieces, but I don''t see how
to wrap
> them up
> with some syntactic sugar as shown above.
>
> Michael
>
I think this might be what you''re looking for:

# in a helper.rb:

   def collapsible_fieldset(options = {}, &block)
     insert = Proc.new {|text| concat text, block.binding}
     insert["<fieldset>"]
     captured_text = capture(&block)
     insert[captured_text]
     insert["</fieldset>"]
   end

In addition, you can actually pass parameters *back* to your block if  
you call the capture method with parameters:

captured_text = capture(info, &block)

This latter feature relies on a patch that was recently applied to  
the Rails code base (see http://dev.rubyonrails.com/changeset/1459).   
I think it''s in Rails 0.13.1 already.

Duane Johnson
(canadaduane)

On Friday 29 July 2005 19:21, Duane Johnson wrote:
> I think this might be what you''re looking for:
>
> # in a helper.rb:
>
>    def collapsible_fieldset(options = {}, &block)
>      insert = Proc.new {|text| concat text, block.binding}
>      insert["<fieldset>"]
>      captured_text = capture(&block)
>      insert[captured_text]
>      insert["</fieldset>"]
>    end
Thanks, that works ... and gave me a serious headache until I noticed 
that Proc#[] is a synonym for Proc#call. My resulting code looks 
slightly different, nevertheless

    def collapsible_fieldset(options = {}, &block)
      html = ''<fieldset>''
      html << capture(&block) if block_given?
      html << ''</fieldset>''
      Binding.of_caller do |binding|
        concat(html, binding)
      end
    end

Michael

-- 
Michael Schuerig                         Those people who smile a lot
mailto:michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org                          
Watch the eyes
http://www.schuerig.de/michael/    --Ani DiFranco, Outta Me, Onto You

>     def collapsible_fieldset(options = {}, &block)
>       html = ''<fieldset>''
>       html << capture(&block) if block_given?
>       html << ''</fieldset>''
>       Binding.of_caller do |binding|
>         concat(html, binding)
>       end
>     end
A bit off topic but fyi: I recommend using the tag and content_tag
helpers in helpers instead of plain html emitting:
>     def collapsible_fieldset(options = {}, &block)
>       html = content_tag :fieldset, (capture(&block) if block_given?)
>       Binding.of_caller do |binding|
>         concat(html, binding)
>       end
>     end
-- 
Tobi
http://www.snowdevil.ca - Snowboards that don''t suck
http://typo.leetsoft.com - Open source weblog engine
http://blog.leetsoft.com - Technical weblog

On Saturday 30 July 2005 16:09, Tobias Luetke wrote:
> I recommend using the tag and content_tag
> helpers in helpers instead of plain html emitting:
Any particular reasons?

Michael

-- 
Michael Schuerig                            This is not a false alarm
mailto:michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org                        
This is not a test
http://www.schuerig.de/michael/                      --Rush, Red Tide