[Metafacture] how to access a specific value (index/occurrence) after applying a filter in an entity

[Thomas Gängler]

Hi,

we would like to implement the following use case:

1. we have a kind of mabxml, excerpt:

<?xml version="1.0" encoding="UTF-8"?>
<datei xmlns="http://www.ddb.de/professionell/mabxml/mabxml-1.xsd" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://files.dnb.de/standards/formate/mabxml-1.xsd">
     <datensatz typ="h" status="n" mabVersion="M2.0">
         <feld nr="001" ind=" ">06978834</feld>
         ...
         <feld nr="076" ind="v">5</feld>
         <feld nr="077" ind="p">00872805<tf/>Roll, Gernot</feld>
         <feld nr="077" ind="p">00872284<tf/>Thomas, Eugen</feld>
         ...
     </datensatz>
</datei>

2. with a filter statement we can access values for specific mab keys, 
e.g., 076v (note a pre-processing-step in our workflow is the RDFization 
of the data source (that's why the uris and rdf:value properties ;) ))

<?xml version="1.1" encoding="UTF-8" standalone="no"?>
<metamorph xmlns="http://www.culturegraph.org/metamorph"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" entityMarker="&#30;"
	version="1" xsi:schemaLocation="http://www.culturegraph.org/metamorph 
metamorph.xsd">
	<meta>
		<name>mapping1</name>
	</meta>
	<rules>
		<combine name="ok" value="${out}" sameEntity="true" reset="false">
			
			<!-- filter elements -->
			<data
			 
source="http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#feld&#30;http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#nr">
				<equals string="076" />
			</data>
			<data
			 
source="http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#feld&#30;http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#ind">
				<equals string="v" />
			</data>

			<!-- value of attribute path that should be selected for further 
processing -->
			<data name="out"
			 
source="http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#feld&#30;http://www.w3.org/1999/02/22-rdf-syntax-ns#value" 
/>

		</combine>
	</rules>
</metamorph>

3. with a filter statement + occurrence function we can access specific 
values for specific mab keys (until the key is a repeatable element), 
e.g., 077p (note therefore we modified the example and deleted the 
second occurrence of the 077p field)

<?xml version="1.1" encoding="UTF-8" standalone="no"?>
<metamorph xmlns="http://www.culturegraph.org/metamorph"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" entityMarker="&#30;"
	version="1" xsi:schemaLocation="http://www.culturegraph.org/metamorph 
metamorph.xsd">
	<meta>
		<name>mapping1</name>
	</meta>
	<rules>
		<combine name="@ok" value="${out}" sameEntity="true" reset="false">
			<data
			 
source="http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#feld&#30;http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#ind">
				<equals string="p" />
			</data>
			<data
			 
source="http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#feld&#30;http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#nr">
				<equals string="077" />
			</data>

			<data name="out"
			 
source="http://www.ddb.de/professionell/mabxml/mabxml-1.xsd#feld&#30;http://www.w3.org/1999/02/22-rdf-syntax-ns#value" 
/>

		</combine>
		<data name="ok2" source="@ok">
			<occurrence only="2" />
		</data>
	</rules>
</metamorph>

====================================================

So now we would like to enable this functionality also for repeatable 
elements (as the 007p key in the example above is one of). Therefore we 
need to ensure to collect all values of an entity that match the filter 
criteria (nr = 077 and ind = p) and apply the occurrence function in 
context of the entity boundary. We tried to experiment with nested 
combines (and with various variants of the parameters for reset, 
flushWith and sameEntity). However, so far without any success ... we 
always got none or all values back that match the filter criteria :\

Thanks a lot in advance for all your help.

Cheers,


Thomas