I quickly solved it with some kind of hack for those interested, but I'm
still curious if the kind of binding I described is possible at all.
Cheers,
Geert-Jan
A hack that's working:
introduced 2 extra fields: facetmaxInc and FacetOld;
public void setFacetCounter(int facetCounter)
{
this.facetCounter = facetCounter;
if(facet!=null && facet.equals(facetold))
{
facetMaxInc = facetMax;
facetold = facet;
}
if(facet!=null && facet.getFacet().isSelected())
{
facetMaxInc++;
}
}
and check on facetMaxInc.
Britske wrote:
>
> I need a bit of introduction to lay down the problem, so please bare with
> me:
>
> I have a component which renders lists of items. A parameter
> (childcounter) keeps track of the number of rendered items in the current
> List.
>
> I have the requirement. to be able to define on a per-page basis how many
> items are rendered at max. I implemented this by simply binding
> childcounter param and checking it against a field (say: maxitems) on the
> page. Depending on that I can decide on a per-page basis what to do with
> items that exceed the maxitems-threshold. (render different blocks, etc)
> So far so good.
>
> Currenly Im using this component to render facets
> (http://en.wikipedia.org/wiki/Faceted_classification) as part of a
> navigation menu. The requirement is to (for each list) render all SELECTED
> facets first and then render x (say 5) UNSELECTED facets per list, where x
> is defined by maxitems.
>
> The problem:
> the component doesn't know (and shouldnt know) that it is rendering
> facets. So it doens't know if a facet is selected or unselected. Based on
> that the childcounter is incremented each time a selected or unselected
> facet is rendered, and the maxitem-treshold is reached when 5 facets per
> group are rendered (independent whether they are selected or unselected).
> Obviously thats not what I want.
>
> The solution (so I thought)
> 1. The component doens't know that it's rendering facets, but the page
> knows. Moreover, the component outputs the item that it is currently
> rendering. (the facet in this case).
> 2. the param childcounter of the component is bound to the page field
> 'facetCounter'
>
> since as I understand it a param-binding is bi-directional I did the
> following:
>
> Page:
> --------------------------
> @Component(parameters = {"result=facetdsText",
> "row=gGroup","childrow=facet","ulClass=literal:facets",
> "childcounter=facetcounter"})
> private CompositeFlexLi facetBlock;
>
> public void setFacetCounter(int facetCounter)
> {
> if(facet==null || !facet.getFacet().isSelected())
> {
> this.facetCounter = facetCounter;
> }
> }
>
> What it does is obvious:
> 1. the component renders and updates childcounter, which in effect calls
> setFacetCounter(int facetCounter), since its bound to facetCounter.
> 2. facetCounter is only updated when the current item is a UNSELECTED
> facet (which it knows in contrast to the component)
>
> The actual problem now is that facetCounter indeed is only updated when a
> facet is unselected, but the parameter 'childcounter' is still updated,
> although it is bound to the field facetCounter which is not updated (they
> aren't in sync).
> The behavior now is the following: (say i have 2 selected facets)
> childcounter: 1,2,3,4,5
> facetfield: 0,0,3,4,5
>
> while i figured it would be:
> childcounter: 0,0,1,2,3,4,5
> facetfield: 0,0,1,2,3,4,5
>
> Was I expecting to much 'binding-magic' to happen here, or am I missing
> something?
> If not, what would be your suggestion to tackle this issue? (making the
> component aware that its rendering facets is as I explained no option)
>
> Thanks in advance,
> Geert-Jan
>
>
>
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