How to filter with metadataPrefix

[cyrilpestel]

I don't see how can we retrieve the metadataPrefix from the request to the methods getItems, getIem and getItemIdentifiers.

I just want to make a query to the data source with the metadataPrefix.

[mmalmeida]

I am not sure I understand your question - what class is this, and what are you trying to do?

[cyrilpestel]

I'm trying to implement a DataProvider. So I've created a class that implements the ItemRepository interface (com.lyncode.xoai.dataprovider.repository package). In this interface, there are getItem, getItems and getItemIdentifiers methods.

So I've supposed that class where I can get metadata from my data source (a triplestore actually).

For instance, the getItem get one parameter named identifier. And there is no metadataPrefix so that I can make a SPARQL query that filter resources based on a specific metadataPrefix.

But may be I'm wrong ?

[joao-de-melo]

Hi

the metadataPrefix is used to define the format of your response. For example oai_dc. There is this assumption that not all items are displayable within the given format. As so, yes it can be used to folter out items but usually is not used.

[cgendreau]

Hi,
We also have a similar issue when implementing a DataProvider that offers more than 1 MetadataFormat.
When we implement com.lyncode.xoai.dataprovider.repository.ItemRepository, the getItem(String s) method needs to build an Item object but the metadata to use is unknown.
In other words, how do we determine the metadata to use in our Item implementation so the Metadata getMetadata() method will generate to correct format? We could probably use a Transformer but since we can generate the metadata in both format dynamically, it would be great to know the MetadataFormat that was requested so we don't have to use a Transformer.

What do you think?

https://github.com/DSpace/xoai/blob/master/xoai-data-provider/src/main/java/org/dspace/xoai/dataprovider/handlers/GetRecordHandler.java#L45