Rails core - Dec 2005 - Preserving fallback with RJS

Hi guys,
I really like RJS. I think they''ll replace partials in alot of
instances. Unfortunately, because they''re automatically used like
.rhtml and .rxml and are hard to specifically specify it makes it
messy to preserve fallbacks when using them. For instance, using
partials instead of rjs, my create method might look like:

def create
  post = Post.new(params[:post])
  ...

  if @request.xhr?
    # render partial
  else
    # do other things and let the rhtml be rendered
  end
end

Is there a way to do this with rjs? Really, I guess I''m looking for a
way to specify when I want to render an RJS template over another. 
Thoughts?

Also, I''ll show the code that I think pertains so you can see what
might need to be changed.

Looking at the render code which controlls which template we go to...

    def pick_template_extension(template_path)#:nodoc:
      if match = delegate_template_exists?(template_path)
        match.first
      elsif erb_template_exists?(template_path):       
''rhtml''
      elsif builder_template_exists?(template_path):    ''rxml''
      elsif javascript_template_exists?(template_path): ''rjs''
      else
        raise ActionViewError, "No rhtml, rxml, rjs or delegate
template found for #{template_path}"
      end
    end

    def render_file(template_path, use_full_path = true, local_assigns = {})
      @first_render      = template_path if @first_render.nil?

      if use_full_path
        template_extension = pick_template_extension(template_path)
        template_file_name = full_template_path(template_path,
template_extension)
      else
        template_file_name = template_path
        template_extension = template_path.split(''.'').last
      end

      template_source = nil # Don''t read the source until we know that
it is required
      .......
    end

With local_assigns at the end of the method definition it makes it
tough to allow for a variable to specify rjs templates or the like
which would be passed to pick_template_extension. There may be a
better way to modify the code to do this.


Kev

On 12/18/05, Kevin Clark <kevin.clark@gmail.com>
wrote:
> Hi guys,
> I really like RJS. I think they''ll replace partials in alot of
> instances. Unfortunately, because they''re automatically used like
> .rhtml and .rxml and are hard to specifically specify it makes it
> messy to preserve fallbacks when using them. For instance, using
> partials instead of rjs, my create method might look like:
>
> def create
>   post = Post.new(params[:post])
>   ...
>
>   if @request.xhr?
>     # render partial
>   else
>     # do other things and let the rhtml be rendered
>   end
> end
My #create/#update actions redirect on regular requests and render rjs
templates on xhr requests.  Therefore, I haven''t really ever run into
this particular issue.

One possible solution would be to render an rjs partial.

if request.xhr?
  render :partial => ''create'' # _create.rjs
else
  flash[:notice] = ''created.''
  # renders create.rhtml
end

--
rick
http://techno-weenie.net