Caching callbacks

[cpsievert]

• Implement

  • https://github.com/ropensci/drake seems like a promising solution to handle more than just pure functions
  • If drake doesn't pan out, use https://github.com/r-lib/memoise
  • Could more be done to support this in dash-renderer (i.e., keep a hash table of md5 sums of R/python objects)?

• Document a complement to https://plot.ly/dash/performance

[rpkyle]

@alexcjohnson Is this something that should be on the roadmap once hot reloading and index customization have been implemented?

[alexcjohnson]

Interesting idea to build support for this into renderer - it would need to be opt-in for each callback that knows caching is OK, but I can see it being a big help in certain cases. If you want to make an issue in the main dash repo for this feel free.

Other than that, I don't think we want to build this functionality into the back end for now. Figuring out the R equivalent of https://plot.ly/dash/performance would be nice though.