This feature was requested in this thread: Is it possible to hide common rows under a spoiler?
There are two ideas how it could be implemented:
1. Group rows by single or multiple fields (similar to SQL’s
GROUP BY). Demo
Pros: easier for use (no need to prepare data in special way like in variant 2).
Cons: less flexibility comparing to variant 2.
item ID -
parent ID relation. Demo
Pros: very flexible.
Cons: user will need to prepare data to reflect relations between records. But since it’s quite common pattern of storing hierarchies in database - the data may be already in right format.
Also, we could implement both variants and add a setting to choose right one.