Re: complex components

thanks for the response. I think this will help me figure it out.

AFAIK, Tiles does not have a true component model as Tapestry does. 
Doing the presentation is rather easy, but creating truly independent 
components (with behavior and resources) seems impossible.


[email protected] wrote:
> Please check the documentation about "informal parameters".  Basically, these 
> are a back door that allow you, for most components, to specify additional HTML 
> attributes as either static or dynamic properties.
> 
> In your case, you can create a component that subclasses AbstractComponent and 
> provides a render method:
> 
>   public void render(IMarkupWriter write, IRequestCycle cycle)
> 
> This is how all the primitive components (Insert, Foreach, TextField, etc.) are 
> written.
> 
> You can also mix and match (you can always mix and match in Tapestry).
> 
> The render method isn't defined in IComponent, it's defined in IRender.  If you 
> want, you can have other classes do some of the response rendering.
> 
> There's a Delegator component.  Its delegate parameter must implement IRender.  
> Doesn't have to be a component, just implement IRender and the render() method.
> 
> In your Calendar component case, the table(s) for the calendar itself might be 
> easier to write in Java code than as HTML templates.
> 
> You'll notice that IMarkupWriter is like a PrintWriter (mostly) with some 
> additional improvements related to writing out XML style tags and attributes.  
> You won't have to worry about quotes and such.
> 
> 
> 
> --
> [email protected]
> 
> http://tapestry.sf.net
> 
>>Hello,
>>
>>Being a newbie to Tapestry I chose to get my feet wet by implementing a 
>>little, however reasonably complex component - a calendar which should 
>>be fully localized and provide a way to move forward and backward 
>>monthwise, etc. I already have it implemented in struts/tiles, and 
>>wanted to see how Tapestry fares.
> 
> 
> I haven't looked at Tiles but those who have (and whose opinions I trust) 
> tell me that they vastly prefer Tapestry.
> 
> 
>>As a first resume, I must say that Tapestry has a rather steep learning 
>>curve - mostly caused by the multiple files one has to handle for each 
>>and every little item (like implementing a foreach loop or a conditional 
>>branch). Tiles tags are  definitely simpler to handle - and scripting a 
>>JSP (or Velocity) is the easiest.
> 
> 
> I think you'll like 2.4 ... it's a best of all worlds situation.  Less in the
> page specification ... maybe no page specification at all.  You'll be able 
> to do things like:
> 
>    <span jwcid="foreach:@Foreach" source="[[ itemsToDisplay ]]">
>    <li><span jwcid="@Insert" value="[[ components.foreach.value ]]"/>
>    </li>
>    </span>
> 
> The [[ ... ]] surround an OGNL expression, much like a <binding> 
> in a page specification.  The "@Type" syntax replaces the <component> entry in
> the page specification.  You can leave many components anonymous.
> 
> It's a bit less of the "perfect, clean separation", but it's more practical
> for many, especially those moving in from other environments.
> 
> 2.4 is in active development, even as we try and roll out 2.3.
> 
> 
> 
>>To some extent I can see this is due to the complex logic involved in 
>>the problem. The calendar cannot be layed out statically in HTML, with 
>>individual items replaced by business logic results - it requires a 
>>nested loop with conditionals inside. Expressing this type of logic in a 
>>template language is simply a pain (after all, this is what we have 
>>programming languages for).
>>Doing this in a html template language like Tapestry has almost only 
>>drawbacks - the HTML becomes completely unmaintainable, both for humans 
>>and for design tools, and runtime efficiency is also questionable.
>>
>>OK, after ranting, heres my immediate questions:
>>
>>1. Is there a recommendation for situations as the above? Is there a way 
>>to directly write parts of the component to the response stream from a 
>>Java method when the logic becomes too complex?
>>
>>2. I need to also dynamically determine some tag attributes (i.e., 
>>"class=" style attributes). In a JSP, I can write something like <td 
>>class="<%=byBean.getStyle()%>">. How is this done with tapestry?
>>
>>thanks,
>>Christian Sell
>>
>>
> 
> 





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