Fwd: [web-devel] missing web component needed: server-side page control

Alberto G. Corona agocorona at gmail.com
Tue Jun 22 11:27:16 EDT 2010

I forgot to cc this to the list. sorry

---------- Forwarded message ----------
From: Alberto G. Corona <agocorona at gmail.com>
Date: 2010/6/22
Subject: Re: [web-devel] missing web component needed: server-side page
To: Michael Snoyman <michael at snoyman.com>

Hi Michael,
Great to know that you are interested!.

Good to know that you are working on widgets. I´m thinking about the same
idea, but I ephasize the dynamic nature, that is , not only the widgets
could be populated from haskell data structures, but will use the server
side control to make them dynamic, so they can  interact with haskell server
code without refreshing the whole page.

I tough on the need of an HTML DOM, because in my view,  we need a 1:1
mapping between the browser and the server in  XML manipulation
primitives. Because Javascript uses HTML DOM. Much of HTML DOM methods are a
single call to the corresponding XML DOM in HXT. But some other, like style
manipulation are different.

My idea is to have in the server a copy of the HTML tree. Any modification
on the server will be forwarded to the client.  For example, the innerHTML
method should be executed in the server as such:

setInnerHTML element text=
       modify the local XML element with XML DOM
       if does not exist, exception raised
       if success, add "element.innerHTML= text" to the Ajax queue (the
javascript listener will eval(uate) it in the client

having a local XML tree copy permits not only checking for errors in the
server but also to query for document properties. referential transparency
permits to share the unmodified XML branches for many client sessions. But I
don´t went deep on thinking about it. neither I know the technology used in
ASPX.NET of JavaServer Faces to do server control. It is really difficult to
guess it doe to the confusing documentation. I can only guess  from the

Maybe we have to do a research on the best way to communicating client and
server for server control, the methods to be used etc...

2010/6/22 Michael Snoyman <michael at snoyman.com>

Sounds interesting. I just released Yesod 0.3.0, and had in mind that 0.4.0
> will focus on a concept I was calling widgets. It sounds very similar to
> what you're talking about here, so I would definitely be interested in
> collaborating with you.
> I'm not sure if writing DOM manipulation code ourselves is necessarily the
> right approach. It might make more sense to simply leverage an existing
> Javascript library (my personal preference being jQuery).
> I have to get back to "real work" for the rest of the day, but I'd like to
> hear any other thoughts you have on the subject.
> Michael
>  On Tue, Jun 22, 2010 at 2:23 PM, Alberto G. Corona <agocorona at gmail.com>wrote:
>>  Hi web haskellers.
>> A few days ago I mention the need to have  server-side page control
>> available in Haskell. ASP.NET and JavaServer Faces have it.
>> I would like to collaborate with anyone of you interested. I have not
>> much time now but this can change in the coming weeks so I want to
>> know the interest on the subject in advance. I also want to receive
>> comments to the development plan.
>> The main advantages are:
>>   -No Javascript, no Ajax needed when developing dynamic HTML pages
>> (All code becomes pure haskell in the server!!)
>>  -No errors in advanced dynamic HTML code: all is statically typed
>> haskell (someone bets more?)
>>   -Clear separation of HTML presentation from page control code
>>   -Extensibility: makes possible to create custom controls, like HTML
>> tables automatically generated from haskell containers etc
>> All this will unleash the full power of haskell in the Web!!!
>> It is compatible and orthogonal with page templating and all other web
>> stuff. I think that it is a  two month work.
>> basically what we have to do is the following:
>>   0 develop a Haskell HTML DOM library. Just 31 objects to manage HTML
>> trees
>>      See the HTML DOM Objects Reference at
>> http://www.w3schools.com/jsref/default.asp
>>       I suppose that this is not yet done
>>      Can make use of the XML structure defined in HXT
>> http://hackage.haskell.org/package/hxt-8.5.2. HXT has namespace
>>      support. This is needed for defining custom attributes and tags (4
>> and 5).
>>     each HTML DOM method will do two basic things:
>>           a) update a copy of the HTML page tree in the SERVER
>>           b) send trough an Ajax channel the equivalent javascript
>> method, that will be executed in the web browser
>>    3 create a minimum javascript module that:
>>         read Ajax responses and execute them in the web browser, for
>> the above functionality
>>         listen for events and forward them to the server trough Ajax.
>>    4 define additional XML attributes to be interspersed in the HTML tree
>> for
>>        specifying url' s in the server where the server events will be
>> forwarded  (for 3)
>>           <button server:onclick="http://server/path...">
>>    5 a mechanism for defining custom XML tags for extensibility: with
>> the name, the parameters and the library code that handle it
>>      example of custom tag inserted in the HTML: <t:table
>> t:source="#{hasjkelldata} param1=......>
>>   6 some templating that read 5 and produces a HTML tree and Haskell code.
>> So, people, feel free to question anything. This is just the starting
>> point to put ideas in the table and discuss all of this
>> _______________________________________________
>> web-devel mailing list
>> web-devel at haskell.org
>> http://www.haskell.org/mailman/listinfo/web-devel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.haskell.org/pipermail/web-devel/attachments/20100622/88db4cd3/attachment.html

More information about the web-devel mailing list