Rails - Sep 2005 - Agile Web Dev with Rails: The Web, V2.0 - Bug in Multiple Updates?

Hi All, 

Has anyone been able to the code listed under Multiple Updates to run as 
described? Multiple updates is updating more than one DOM element after a 
link_to_remote call.

Muiltiple Updates is page 392 in my PDF and begins:

"If you rely heavily on the server to do client-side updates, and need more
flexibility than the :update => ''elementid'' construct
provides, callbacks
may be the answer. The trick is to have the server send JavaScript to the 
client as part of an AJAX response. As this JavaScript has full access to 
the DOM, it can update as much of the browser window as you need. To pull 
off this magic, use :complete => "eval(request.responseText)"
instead of
:update. You can generate JavaScript within your view that is then delivered 
to the client and executed. "

I''ve tried running this code downloaded from the PragProg site and
can''t
reproduce the results. The other Ajax examples seem to work okay.

Can anyone confirm or deny that this code works so I can try to figure out 
if I have some sort of environment issue?

Thanks!

Tim Case
tcrails2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org


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Hi !

Tim Case said the following on 2005-09-02 12:34:
> as you need. To pull off this magic, use :complete => 
> "eval(request.responseText)" instead of :update. You can generate
> JavaScript within your view that is then delivered to the client and 
> executed. "
> 
> I''ve tried running this code downloaded from the PragProg site and
can''t
> reproduce the results.  The other Ajax examples seem to work okay.
> 
> Can anyone confirm or deny that this code works so I can try to figure 
> out if I have some sort of environment issue?
I can confirm that it works.  In fact, this is how I do it:

function acceptDrop(draggable, droppable, event) {
   var team = draggable.parentNode.getAttribute(''team'');
   if (null == team) team = '''';

   var copy = false;
   if (event.ctrlKey) copy = true;

   new Ajax.Request(''<%= url_for :action =>
''reschedule'' %>'',
       {onLoading:   function(request) {
            Element.hide(''message-area'');
            new Effect.Fade(draggable);},
        onComplete:  function(request) {
            <%= evaluate_remote_response %>},
        method:      ''post'',
        parameters:
            ''item='' + draggable.id +
''&time_slot='' + droppable.element.id
            + ''&team='' + team +
''&copy='' + copy});
}

Notice the onComplete handler in my Ajax.Request.

My reschedule view looks like this:
<%= update_element_function(''schedule-container'',
       :content => render(:partial => ''schedule''))
-%>
<%= update_element_function(''message-area'',
       :content => %Q(<div
class="message">#{flash[:notice]}</div>))
       unless flash[:notice].blank? -%>
<%= visual_effect(:appear, ''message-area'')
       unless flash[:notice].blank? -%>
<%= update_element_function(''unscheduled'',
       :content => render(:partial => ''unscheduled'',
                        :collection => Job.unscheduled)) -%>

NOTE: onDrop() as shown above wouldn''t allow you access to the event 
object.  You need a patched copy of the dragdrop.js library which passes 
the event object to the callbacks.

Hope that helps !
François