How to get document datasource in another Custom Control? - lotus-notes

Question

I have an xPage with this content:
<div class="lotusFrame">
<xc:layoutCommonBanner />
<xp:callback facetName="facetTitleBar" id="callbackTitleBar" />
<xc:layoutDiscrepancyPlaceBar />
<div class="lotusMain">
<div class="lotusColLeft">
<xp:callback facetName="facetColLeft" id="callbackColLeft" />
</div>
<div class="lotusColRight">
<xp:callback facetName="facetColRight" id="callbackColRight" />
</div>
<div class="lotusContent">
<xp:callback facetName="facetContent" id="callbackContent" />
</div>
</div>
<xc:layoutCommonFooter />
<xc:layoutCommonLegal />
</div>
As you can see, there are several custom controls in it composing layout. In the facetContent, there is a document with document datasource. It's the only document in the page. I need to get this document somehow in the layoutDiscrepancyPlaceBar custom control.
I found some old articles on the web with undocumented feature called currentDocument. It should be on every page with document datasource. But it doesn's work. I have Domino 8.5.2 and currentDocument seems to be no longer supported.
Can you help me out? How can I get document datasource from one custom control in another custom control. Is it even possible?
Thanks in advance, Jiří
EDIT: OK, it is still supported, but it only works in custom control, that is included inside the one with document datasource. In the case scenario above it doesn't work.

Answer 1

Your best option is to hand over the binding name in a custom property. (lets call it bindto. Then you bind your field to
"${#{"+compositeData.bindto+"}}"
See details here (inside the prezi)
P.S. currentDocument is documented somewhere.

Answer 2

You can also pass a handle on the data source directly to the custom control, as well as the name of the item to bind to on the data source. Because EL supports array syntax as well as dot syntax, this allows you to define expressions like this:
#{compositeData.dsn[compositeData.fieldName]}
(where "dsn" is the property being passed the handle on the data source, and "fieldName" is the property being passed the name of the item to bind to on that data source.)
More details on this approach can be found here.