Summary:
`copyText` is generated when building rows for table, and is typically filled by JSON stringifying the incoming data. That is a pretty expensive process that could be done lazily. As shown in later diffs, this reduces the generation of rows for tables from ~18ms to ~3ms, which makes rendering a lot smoother.
(n.b. fixing the code duplication in the managedtables is part of the component lib plan)
Reviewed By: passy
Differential Revision: D21929660
fbshipit-source-id: 67cc69945e2bb28a6462a9d9ab765e33ced89378