Seaside + Comet

Hi list,
I`m a newbie with seaside and comet. After loading successfully
SeasideComent on VW, I looked at the examples of Comet.
In the counter example we can see these code:

        pusher javascript: (SUElement new
                id: 'count';
                update: self count contents asString)

The update method receives a string to be updated in the page. I`m
trying to reproduce the renderOn: behaviour of a SUComponent so that
the string to be pushed is a result of the rendering process.
The best solution that I have is a modification of CTChat>>push:
aBlock. This is the code:

                contextHandle := self pusher handlers first context.
                document := (Seaside.WAHtmlStreamDocument new)
                                                        bodyStream;
                                                        yourself.
        context := WARenderingContext new document: document; actionUrl:
contextHandle actionUrl.
        aWebView renderWithContext: context.
        htmlFragment := document stream contents.

                pusher
                        javascript: (Seaside.SUElement new
                                                                        id: aWebView id;
                                                                        update: htmlFragment).

It works fine for rendering, but aWebView ( subclass of SUComponent )
renders itself using an Updater like this:


| fid mid |

                fid := aRenderer nextId.
                mid := aRenderer nextId.
                aRenderer form
            id: fid;
                    with: [ aRenderer checkbox
                                    value: self model model value;
                                    callback: [ :value |  self model model value: value ];
                                                onClick: (aRenderer updater
                                                                       id: mid;
                                                                       triggerForm: fid;
                                                                       callback: [ :r |  ]).
                                        aRenderer label with: self model label text].


The problem is that the updater is not working after the re-rendering.
I supposed that the problem is with the push-like code. Is there a
solution for using comet and the renderOn: transparently?
Regards
Esteban
_______________________________________________
Seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

SUElement has that already. Try something like:

pusher javascript: (html element
     id: 'count';
     render: [ :r | r anchor callback: [ ... ]; with: ... ])

> The problem is that the updater is not working after the re-rendering.
> I supposed that the problem is with the push-like code. Is there a
> solution for using comet and the renderOn: transparently?

I don't exactly understand what you are trying to do. If you push code
containing callbacks, then all the connected sessions will receive
exactly the same string. This means all the callbacks will point (and
be evaluated) in the session that did the rendering. Moreover people
will be able to hijack the initiating session, as you just hand out
your private key to everybody. I don't think you want that, but
unfortunately this cannot be avoided easily.

What I suggest you to do is to just trigger an event handler in all
your clients so that they can make an update request on their specific
session.

Was this what you wanted to do?

Cheers,
Lukas

--
Lukas Renggli
http://www.lukas-renggli.ch
_______________________________________________
Seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Thanks for your replay Lukas!

On 1/19/07, Lukas Renggli <[hidden email]> wrote:
The problem is that html is undefined in my context. May be what I`m
trying to reproduce is somewhat complicated. I`m going to explain it
more precesily:
* I have a component that understands renderOn:
* Also the component has a pusher for updating itself.
* I have a process that periodically (5 seconds) sends an update
message to the component.

I want to reuse the renderOn: behaviour. For example the update
message to the component don`t have a reference to the render, so my
problem is to get a render in order to use the renderOn message.
How do I get the render in that context? is it possible?



--
Saludos
Esteban
_______________________________________________
Seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

> I want to reuse the renderOn: behaviour. For example the update
> message to the component don`t have a reference to the render, so my
> problem is to get a render in order to use the renderOn message.
> How do I get the render in that context? is it possible?

If you use

     SUElement new

the element won't be able to render, as it doesn't know the context.
Therefor you should use the factory methods

     html element ...

or

     html scriptaculous element
     (the new way of doing it)

what basically does the same but assigns the curent context to the
element, so that it can do fancy stuff like rendering and registering
callbacks.

> * I have a process that periodically (5 seconds) sends an update
> message to the component.

Why don't you use the periodical updater then? Is there a difference
between pulling every 5 seconds (AJAX, Scriptaculous, easy) and
pushing every 5 seconds (Comet, relatively complicated and resource
hungry)?

Cheers,
Lukas


--
Lukas Renggli
http://www.lukas-renggli.ch
_______________________________________________
Seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Lukas,
The problem is that till know I don`t understand some concepts of
seaside + scriptaculous. May be the best way is to copy some messages
that understands WebView and discuss them. The problem I have now is
that the stream is obviously close.

>>renderContentOn: aRenderer

| actualId  |
actualId:= aRenderer nextId.
self id: actualId.
"store the element"
self element: (aRenderer element id: actualId).
element render: [:r | self primRenderContentOn: r].


>>primRenderContentOn: aRenderer

| fid mid |

fid := aRenderer nextId.
mid := aRenderer nextId.
aRenderer form
             id: fid;
            with: [ aRenderer checkbox
             value: self model model value;
             callback: [ :value |  self model model value: value ];
onClick: (aRenderer updater
               id: mid;
               triggerForm: fid;
               callback: [ :r |  ]).
aRenderer label with: self model label text].

>>invalidate


self element render:[:r | self primRenderContentOn: r].

Remember that, the invalidate is call after 5 seconds the first
request. I can´t find the implementation of html scriptaculous element
in the canvas. Which version are you using? My version is
Scriptaculous-lr.163.mcz 19 December 2006 3:24:29 pm for VW.

On 1/20/07, Lukas Renggli <[hidden email]> wrote:
You are right. The problem is much more complicated. This work is for
a subject of the faculty. I`m trying to reuse the UIPainter of VW for
generating the UI for a web application ( with certain restrictions
and without taking into consideration resources ). So that to migrate
the same application to the web is just a matter of minutes. My
approach of solving the problem is to generate the typical UI on the
server. Then I build proxies of seaside for interacting with the UI (
of course a subset of the functionality ) and rendering. The main
objective is to use the same widgets, not custom displayOn: object`s.
Your help is really appreciated!



--
Saludos
Esteban
_______________________________________________
Seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

I don't know UIPainter. What worked for me to do user-interfaces for
the desktop and for the web is to use Magritte. The content management
system Pier primarily has got a web interface using Seaside, however
almost all functionality can also be used without additional code in
Morphic (the Squeak GUI framework).

> Remember that, the invalidate is call after 5 seconds the first
> request. I can´t find the implementation of html scriptaculous element
> in the canvas.

Why do you make your life difficult with Comet? If you know the update
frequency in advance, then I see no point in using Comet. Have a look
at the class SUPeriodicalTest, why doesn't that work for you?

> Which version are you using? My version is
> Scriptaculous-lr.163.mcz 19 December 2006 3:24:29 pm for VW.

Aha, ok. I didn't know that you are on VW. Don't worry about the
message #scriptaculous, I only started with this refactoring recently
to avoid further pollution of the RenderingCanvas ... it is something
that comes in the future. There is no difference in the behavior.

Cheers,
Lukas

--
Lukas Renggli
http://www.lukas-renggli.ch
_______________________________________________
Seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Thanks Lukas for your help!

On 1/20/07, Lukas Renggli <[hidden email]> wrote:

--
Saludos
Esteban
_______________________________________________
Seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside