Magritte usage pattern

[Norbert Hartl]

On Sat, 2007-03-31 at 20:07 +0200, Lukas Renggli wrote:
> Hi Norbert,
> 
> > For customization I put every little bit in a wrapper class
> > around the generated Magritte component. This is for customizing
> > the generated component as well as to do some manual html if
> > it isn't avoidable. I have the feeling that this is not the
> > right way to do but I have no better idea. To minimize the effort
> > to do a component for a model component I've built a base class
> > which should ease the customization of the component.
> 
> are your convenience classes available somewhere? I think that many  
> people could profit from these extensions and they could maybe even  
> be integrated somehow into the core package?
> 
You are right. I will finish them a little and post them here.

> > - really complex layout cases
> >   I have one case where it is necessary to put css classes to some of
> >   the components of a form. The best way I found so far (being dirty)
> >   is to use propertyAt:put: at description level and use this in a
> >   specialized renderer
> 
> You could use #attributes of the descriptions:
> 
> 	aDescription attributes class: 'foo'
> 
Oh, I should have found that :) Looks much better.

> > So far so good. I like to hear your oppions and experiences doing this
> > kind of stuff.
> 
> Your approach sounds fine to me, I also found myself doing similar  
> things.
> 
> > Another problem I have no solution til now is the mixture of models  
> > into
> > one component. Sometimes you build your data model and then page  
> > layout
> > forces you to edit two objects at the same time. I have no problem to
> > mix descriptions in a desired way. But by invoking asComponentOn: they
> > would have all the same model which is wrong for a subset of the
> > descriptions. Is there any clever way to mix descriptions, set the  
> > model
> > accordingly and then produce the component?
> 
> Indeed you can do that by modifying the accessors of the descriptions  
> of referenced objects. I am copying an example from an earlier post  
> to this mailing list, where #billingAddress and #shippingAddress are  
> weaved into the description of anOrder:
> 
> composedDescription := anOrder description copy
>      addAll: (anOrder billingAddress description collect: [ :each |
>          each copy accessor: (MACascadeAccessor
>              accessor: (MASelectorAccessor selector: #billingAddress)
>              next: each accessor) ]);
>      addAll: (anOrder shippingAddress description collect: [ :each |
>          each copy accessor: (MACascadeAccessor
>              accessor: (MASelectorAccessor selector: #shippingAddress)
>              next: each accessor) ]);
>      asComponentOn: anOrder
> 
Ok, I only imagined to carry more than one model. But to chain selector
invocation is much more clever. It will only work if the objects related
directly but I doubt you need to combine model objects often when they
are not related directly.

For further assistance please remember that you renamed
MACascadeAccessor to MAChainAccessor :) It was in Magritte-Model-206 ;)

> This looks terribly complicated, but with a simple helper function it  
> could made look much simpler.

I didn't try it but it looks not too complicated. 

thanks very much,

Norbert