Index with Map and Reduce that Looks at Internal Types

[mfonnesbeck]

I have an object that contains a history array. The base type of history items is TicketHistoryItem which contains a Timestamp value of when the history change was made, but this history item in the array could be either of the following descendant classes: TicketStatusHistoryItem holding a change in statuses of the original object, a TicketCategoryHistoryItem holding changes in the category of the original object, or a two other types of changes. Internal in the stored document it has a $type value storing the actual class this history item is and lists the fully qualified namespace and class name.

There is a need for querying these objects and grouping them by the TicketStatusHistoryItem history types and getting a count of them based upon the dates (Timestamp) that the changes were made. In order to count how many were a particular status on a date.

Is there a way to create an index that looks at the $type property and filters those objects that contain a TicketStatusHistoryItem with a particular status in the history array? I've tried various ways of accessing this array and filtering/grouping without success and not found any examples as complicated as this in the docs.

[ayende]

Remember that on the server side, you don't actually have your types. It is all JSON.

What you can do is use a JS index, and just operate over the json structure directly