Mark -
I was able to confirm that neither the syntax ${FieldName[idx]} nor ${Fieldname}[idx] appear to work with the 10.2.1 product release when attempting to configure an SMS or E-mail output to pull values out of a list added to a GeoEvent by a GeoTagger processor.
I think I'm able to do what you're trying to do, however, if I incorporate a Field Calculator. I reconfigured the GeoTagger processors in my service to use the 'List' GeoTag Format rather than the default DelimitedValue format. Then, before the enriched event is sent to the Output connector, I configured a Field Calculator (see illustration below) to extract a String element from the List into a new field. Then I reference the new field in the email-text-out Output, to avoid having to combine the square-brackets required for indexing with the curl-brackets used to indicate in the Output's configuration that we are inserting a value from an event field.
[ATTACH=CONFIG]30413[/ATTACH]
You might recognize that a GeoTagger processor is really a specialized implementation of a Field Enricher processor and a spatial filter and consider exactly what you are trying to accomplish with the event enrichment being performed by the GeoTagger. If you were to configure the GeoFences property of your GeoTagger with ".*/.*" the processor would consider all GeoFences in all GeoFence Categories. In this case, I don't think you'll be guaranteed that enrichment will occur in the same order every time. That is to say, if you always pull the 0th item from the GeoTags field (assuming that field is a List) you may not always get the name of a GeoFence from the same category (assuming that you have GeoFences in more than one category). Multiple GeoFences, which may or may not overlap, which are organized in multiple categories, might necessitate you take a specific approach when designing your GeoEvent Service.
We will look into addressing the apparent syntatic limitation when working with event fields which are Groups and Lists in the different Notification output connectors.
Hope this information helps -
RJ
