WebStyle <---> WebApplication

>
> WebApplication>>doesNotUnderstand: aMessage
> "forward a message to a style for processing"
> ^self style
> perform: aMessage selector
> withArguments: aMessage arguments
>
> My troubles began in the tutorial and the #pageFrameWith:title:
>
>     viewMain
>         | e |
>         e := WebElement new.
>         e addTextH1: 'Address book'.
>         self pageFrameWith: e title: 'Address book'
>
>  I guessed that #pageFrameWith:title: must be setting up the page
> layout (the header, menus etc) but was surprised to find that
> #pageFrameWith:title: was not implemented in the WebApplication
> hierarchy.   Why not directly send the message to the WebStyle object
> (and it is less expensive cpu wise) such as:
>
>         self style pageFrameWith: e title: 'Address book'
>
> WebStyle seems to me to incorporate at least the following features:
>  -- setup a page template for the *Aida tutorial* site (the  page
> headers, footers, navigation bars etc)
> -- establish assets for the site (html header information - css files,
> images files, script files)

> Hi Edward,
>
> Edward Stow wrote:
>
>> My question, first up,  how would you create two or more WebStyles  
>> for
>> a site? and apply these to particular pages (or rather WebApplication
>> objects.)
>
> So far no. WebStyle is originally meant to separate design from site  
> to
> site on multi-site hosting environments. For instance I'm running  
> such a
> VW image with 35 sites and each such site has its own subclass of  
> WebStyle.
>
> But why would you actually need WebStyle for each App?

>
>  Le mardi 01 avril 2008 à 20:35 +0200, Janko Mivšek a écrit :
>
> > Hi Edward,
>  >
>  > Edward Stow wrote:
>  >
>  > > My question, first up,  how would you create two or more WebStyles for
>  > > a site? and apply these to particular pages (or rather WebApplication
>  > > objects.)
>  >
>  > So far no. WebStyle is originally meant to separate design from site to
>  > site on multi-site hosting environments. For instance I'm running such a
>  > VW image with 35 sites and each such site has its own subclass of WebStyle.
>  >
>  > But why would you actually need WebStyle for each App?
>  >
>  > > My question led me to investigate WebApplication and WebStyle a bit
>  > > more closely.  These two  classes seem very coupled and because of the
>  > > obscuring (imho) #dnu: implementation ... that redirects many, many
>  > > messages to the style class it makes it difficult to understand the
>  > > framework.
>  >
>  > Yes, this one is funny on first sight but very powerful after you
>  > understand it. In a way It extends Apps to a WebStyle, but for each site
>  > differently. But on the other side is hard to debug and hard to
>  > understand for a newbie. Actually calling style methods explicitly:
>  >
>  >               anApp style pageFrameWith:title:
>  >
>  > is the best way to go and I'll actually change all my code to use this
>  > #style method. Thanks for comming out with that idea!
>
>  I personnaly like self pageFrameWith:title:, it is shorter, and use this
>  very cool overriding of #doesnotunderstand: :)

>
>  Le mardi 01 avril 2008 à 20:49 +0200, Giuseppe Luigi Punzi Ruiz a
>  écrit :
>
> > Hi Jano, list,
>  >
>  > I think, he is talking about 2 webstyles in one app.
>
>  You can use different pageFrameWith: like methods for different kind of
>  apps, for example #pageFrameWith:title, #blogPageFrameWith:title and so
>  on.
>
>  Nico

>
>
> >
>  > In web terms. Think on squeak.org page, I think he is talking about a
>  > style for Home, other for Download, etc.....
>  >
>  > El 01/04/2008, a las 20:35, Janko Mivšek escribió:
>  >
>  > > Hi Edward,
>  > >
>  > > Edward Stow wrote:
>  > >
>  > >> My question, first up,  how would you create two or more WebStyles
>  > >> for
>  > >> a site? and apply these to particular pages (or rather WebApplication
>  > >> objects.)
>  > >
>  > > So far no. WebStyle is originally meant to separate design from site
>  > > to
>  > > site on multi-site hosting environments. For instance I'm running
>  > > such a
>  > > VW image with 35 sites and each such site has its own subclass of
>  > > WebStyle.
>  > >
>  > > But why would you actually need WebStyle for each App?
>  >
>  > _______________________________________________
>  > Aida mailing list
>  > [hidden email]
>  > http://lists.aidaweb.si/mailman/listinfo/aida
>
> _______________________________________________
>  Aida mailing list
>  [hidden email]
>  http://lists.aidaweb.si/mailman/listinfo/aida
>
>

> WebStyle>>pageFrameWith: aWebElement wide: aWideElement title: aTitleString
> "set a web page with standard  page look (navigation bar, header) "
> "Wide element comes below content besides navigation and it have full
> page width"
> | element |
> self app clear;  title: aTitleString. self app htmlHeaderElements.
> " self app add: self headerBanner. "
> element := (WebElement newId: #container)
>
> #htmlHeaderElements is implemented in WebStyle and so this would be better:
>
> self app clear;  title: aTitleString. self  htmlHeaderElements.
>
> This was the second method that I looked at in WebStyle so I don't
> know how prevalent this anti-pattern is in the code.

>
> > As Nicolas said this is hardly called antipattern, just that it is maybe
> > too obvious/not enough hidden from the user. But really, let we come to
> > the better solution if possible. Nicolas already proposed to move
> > #pageFrameWith:title: to WebApplciation to be easily found, you proposed
> >  strict use of #style, any more idea?
> >
>
> Honestly, I'm just trying to keep up with all the knowledge that is flying
> back and forth and trying to put together some coherent documents.
>
>
> I'm on a mission to document...!

Not necesseraly. In this case it is very powerful, and anyway if the

>
>  Le mercredi 02 avril 2008 à 07:05 +1100, Edward Stow a écrit :
>
>
> > On Wed, Apr 2, 2008 at 8:06 AM, Nicolas Petton <[hidden email]> wrote:
>  > >
>  > >  Le mardi 01 avril 2008 à 20:35 +0200, Janko Mivšek a écrit :
>  > >
>  > > > Hi Edward,
>  > >  >
>  > >  > Edward Stow wrote:
>  > >  >
>  > >  > > My question, first up,  how would you create two or more WebStyles for
>  > >  > > a site? and apply these to particular pages (or rather WebApplication
>  > >  > > objects.)
>  > >  >
>  > >  > So far no. WebStyle is originally meant to separate design from site to
>  > >  > site on multi-site hosting environments. For instance I'm running such a
>  > >  > VW image with 35 sites and each such site has its own subclass of WebStyle.
>  > >  >
>  > >  > But why would you actually need WebStyle for each App?
>  > >  >
>  > >  > > My question led me to investigate WebApplication and WebStyle a bit
>  > >  > > more closely.  These two  classes seem very coupled and because of the
>  > >  > > obscuring (imho) #dnu: implementation ... that redirects many, many
>  > >  > > messages to the style class it makes it difficult to understand the
>  > >  > > framework.
>  > >  >
>  > >  > Yes, this one is funny on first sight but very powerful after you
>  > >  > understand it. In a way It extends Apps to a WebStyle, but for each site
>  > >  > differently. But on the other side is hard to debug and hard to
>  > >  > understand for a newbie. Actually calling style methods explicitly:
>  > >  >
>  > >  >               anApp style pageFrameWith:title:
>  > >  >
>  > >  > is the best way to go and I'll actually change all my code to use this
>  > >  > #style method. Thanks for comming out with that idea!
>  > >
>  > >  I personnaly like self pageFrameWith:title:, it is shorter, and use this
>  > >  very cool overriding of #doesnotunderstand: :)
>  >
>  > #doesNotUnderstand:  should come with a warning about the consequences
>  > for its use.
>  Not necesseraly. In this case it is very powerful, and anyway if the
>  webstyle doesn't understand the message, an error will be raised.
>
>  This pattern (not an anti-pattern at all!) is used in other frameworks,
>  in other langages too. If you know Ruby and Rails, you know that
>  accessors are created on the fly this way. You may not agree, but it is
>  still useful IMHO.

> On Wed, Apr 2, 2008 at 9:28 AM, Nicolas Petton <[hidden email]> wrote:
>>  Le mercredi 02 avril 2008 à 07:05 +1100, Edward Stow a écrit :
>>
>>
>>> On Wed, Apr 2, 2008 at 8:06 AM, Nicolas Petton <[hidden email]> wrote:
>>  > >
>>  > >  Le mardi 01 avril 2008 à 20:35 +0200, Janko Mivšek a écrit :
>>  > >
>>  > > > Hi Edward,
>>  > >  >
>>  > >  > Edward Stow wrote:
>>  > >  >
>>  > >  > > My question, first up,  how would you create two or more WebStyles for
>>  > >  > > a site? and apply these to particular pages (or rather WebApplication
>>  > >  > > objects.)
>>  > >  >
>>  > >  > So far no. WebStyle is originally meant to separate design from site to
>>  > >  > site on multi-site hosting environments. For instance I'm running such a
>>  > >  > VW image with 35 sites and each such site has its own subclass of WebStyle.
>>  > >  >
>>  > >  > But why would you actually need WebStyle for each App?
>>  > >  >
>>  > >  > > My question led me to investigate WebApplication and WebStyle a bit
>>  > >  > > more closely.  These two  classes seem very coupled and because of the
>>  > >  > > obscuring (imho) #dnu: implementation ... that redirects many, many
>>  > >  > > messages to the style class it makes it difficult to understand the
>>  > >  > > framework.
>>  > >  >
>>  > >  > Yes, this one is funny on first sight but very powerful after you
>>  > >  > understand it. In a way It extends Apps to a WebStyle, but for each site
>>  > >  > differently. But on the other side is hard to debug and hard to
>>  > >  > understand for a newbie. Actually calling style methods explicitly:
>>  > >  >
>>  > >  >               anApp style pageFrameWith:title:
>>  > >  >
>>  > >  > is the best way to go and I'll actually change all my code to use this
>>  > >  > #style method. Thanks for comming out with that idea!
>>  > >
>>  > >  I personnaly like self pageFrameWith:title:, it is shorter, and use this
>>  > >  very cool overriding of #doesnotunderstand: :)
>>  >
>>  > #doesNotUnderstand:  should come with a warning about the consequences
>>  > for its use.
>>  Not necesseraly. In this case it is very powerful, and anyway if the
>>  webstyle doesn't understand the message, an error will be raised.
>>
>>  This pattern (not an anti-pattern at all!) is used in other frameworks,
>>  in other langages too. If you know Ruby and Rails, you know that
>>  accessors are created on the fly this way. You may not agree, but it is
>>  still useful IMHO.
>
> I have done similiar tricks -- for example on a Row Data Gateway [1]
> to access attribute values from a relational dbms table. This usage is
> a well known pattern / idiom for the #dnu.
>
> [1] http://martinfowler.com/eaaCatalog/rowDataGateway.html
>
>>  >   I'm sure that smalltalkers much wiser than me have
>>  > expressed similiar sentiments.
>>
>>  Again, I do not agree. Look at Object>>doesNotUnderstand: inherence and
>>  you will see how many classes override this message to perform a special
>>  pattern. Some example: ObjectExplorer, MagmaCollectionReader (from Magma
>>  OODB), WAModelProxy (from Seaside), and so on.
>>
> These examples are implementing a well known pattern(s).  EFor example
> WAModelProxy is implementing a proxy that would be difficult without
> the dnu.
>
> ObjectExplorer will be doing massive amounts of introspection needed
> to support the browsing of objects.
>
> The usage in WebApplication is to delegate messages creating a sort of
> mixin class with WebStyle.
>
> I liked this from comp.lang.smalltalk some years ago:
>
> "(Kent Beck had an interesting "koan" button at OOPSLA. It read "Will
> override #doesNotUnderstand: for food!" What was most interesting was the
> very different reactions it got from those doing Smalltalk for 1 year, 2-5
> years, and 5+ years, which went something like "duh," knowing grin, and
> pained expression, respectively!)" [2]
>
> [2] http://groups.google.com/group/comp.lang.smalltalk/msg/85fb5f6714fa3d37?
>
> and
> David Buck points out some of the dangers [3]
>
> [3] http://tinyurl.com/yrxy9p
>
> and Travis Griggs some of the places that it is useful.
>
> [4] http://tinyurl.com/yosjrs
> _______________________________________________
> Aida mailing list
> [hidden email]
> http://lists.aidaweb.si/mailman/listinfo/aida
>

> Edward Stow wrote:
>
>  > #doesNotUnderstand:  should come with a warning about the consequences
>  > for its use.  I'm sure that smalltalkers much wiser than me have
>  > expressed similiar sentiments.
>
>  In Aida we use two such tricks and both you discover immediately :) One
>  is #dnu to connect Apps with WebStyle, other is so called "climbing on
>  the stack" (my term) which finds a reference to the App or session on
>  which you are currently building the page, in case you don't have other
>  means to find it. #app method is such one. More below.