From: Matthieu Stone <matt.stone@...>
Date: 2007-04-02T19:57:54+09:00
Subject: Re: updating an RJS template _while_ executing a method

Hi Tom,

I think that this will answer your questions.

To get rid of the firebug message, just make sure that this routine

><div id="poll_message"><%= session[:message] %></div>
>   <script type="text/javascript">
>   //<![CDATA[
>     <% if @session[:message] && !@session[:message].blank? %>
>       poll_message = true;
>     <% else %>
>       Poll_message = false;
>     <% end %>
>   //]]>
>   </script>

Is rendered in the page before the periodically_call_update routine, it's
easier to place this in a partial, then you can it via RJS in any controller
method. I've added the poll_message div to make things a little more
explicit.

    session[:message] = "let's get it started.."

    respond_to do |format|
      format.js { render :update do |page|
                      page.replace 'poll_message', :partial =>
'poll_message'
                      page.visual_effect :highlight, 'poll_message', 
                                         :duration   => 1,
                                         :startcolor => '"#FFCCFF"',
                                         :endcolor   => '"#FFFFCC"'
                  end
                }
    end


I use the respond_to mechanism to update div's on the page, rather than .rjs
files. I don't need to specify :update => some_div in the
periodically_call_remote routine & I can do other things, such as highlight
the updated message or update another part of the screen using logic in the
controller. There are upsides & downsides to doing things this way, I just
find it easier to do it in the controller as it keeps all my page logic in
the one place.

rgds,
- matt.

-----Original Message-----
From: ruby-talk@hinv.org [mailto:ruby-talk@hinv.org] 
Sent: 02 April 2007 11:17
To: ruby-talk ML
Subject: Re: updating an RJS template _while_ executing a method

Hey Matt,

what I still don't understand is 
where to turn "poll_message" on and off using your JS-code?
Or: what do you mean with "...in a RJS update..."?

-> Inside the RJS-template of "my_io_process"?
That throws quite a few errors.

-> Using inline RJS rendering inside my controller?
(which shouldn't work while also using an RJS template)

-> somewhere else..?

Also:
Do I need to specify a ":update => 'my_div'"
within periodically_call_remote?
When I put this call inside my layout,
Firebug yells at me: "poll_message not defined"...
Is a "var poll_message = false" fine?

Thanks for your help!
Cheers,
  Tom.

---------------------------------
On Sun, 1 Apr 2007 04:43:45 +0900
"Matthieu Stone" <matt.stone@cityticketexchange.com> wrote:

> Here's one way
> 
> In your method doing the IO stuff, update a session variable with the
> message that you want displayed; ie: 
> 
>   def my_io_process
>     session[:message] = "Starting..."
>     do something
>     session[:message] = "Updated message"
>     do something else.. etc
>     session[:message] = nil
>   end
> 
>   
> Create another controller method that just returns the value of
> session[:message].
> 
>   def update_message
>     render :text => session[:message]; :layout => false
>   end
> 
> So now, all you need is a periodic routine that updates a div on the page
> with the session[:message] contents. You can either update the div
directly
> from this call, or like I do, use RJS to do other things on the page. This
> polling is turned on & off by the javascript variable poll_message
> 
> <%= periodically_call_remote(
>       :condition => "poll_message == true",
>       :frequency => 2,
>       :url       => { :action => 'update_message', :only_path => false }
>     ) %>
> 
> 
> You can turn poll_message on & off like this, just include this code in a
> RJS update whenever you want to change turn the polling on & off.
> 
>   <script type="text/javascript">
>   //<![CDATA[
>     <% if @session[:message] && !@session[:message].blank? %>
>       poll_message = true;
>     <% else %>
>       Poll_message = false;
>     <% end %>
>   //]]>
>   </script>
> 
> 
> Rgds,
> - matt.
> 
> -----Original Message-----
> From: ruby-talk@hinv.org [mailto:ruby-talk@hinv.org] 
> Sent: 31 March 2007 17:56
> To: ruby-talk ML
> Subject: updating an RJS template _while_ executing a method
> 
> I have a method doing I/O stuff which takes quite a long time.
> While this method is processed,
> I want the user of my tool to be informed of the current execution state.
> 
> For example,
> if the method opens a file,
> I want my RJS template to render a message such as "opening file XYZ...",
> if the method changes to a directory, message would be "cd to ...".
> 
> As far as I can tell,
> RJS templates are rendered AFTER the corresponding method is executed.
> But I want them to run (sort of) synchronously.
> Or at least have a way to trigger messages while a method is executed.
> 
> Cheers,
>   Tom.
> 
>