TagHistoryProvider.browse NullPointerException?

Module Development
1

Hi,

I’m trying to implement the TagHistoryProvider.browse function to return a set of root level “folders” that contains all the actual tags. Is there a good example on how to do this somewhere?

Here is what I was thinking that the root folder code should look like. If I debug the code, then I can see that it returns a valid Results Object with a valid list of results, but it gives me a runtime error (NullPointerException) when I try to browse from Perspective.

var result = new Results<Result>();
var list = new ArrayList<Result>();
var driver = path.getPathComponent(WellKnownPathTypes.Driver);
var histProv = qualifiedPath.getPathComponent(WellKnownPathTypes.HistoryProvider);

if (null == driver) {
  var assets = new TagResult();
  var p = new QualifiedPath.Builder()
               .setProvider(histProv)
               .setDriver("Assets") // Can we use driver here? (and is there a good explanation of tag parts somewhere?
               .build();
  assets.setHasChildren(true);
  assets.setPath(p);
  list.add(assets);
   ...
}
result.setResults(list);
return result;