#396 interactive computation

[Lee Worden]

What would it take to do calculations on demand, for instance having a form for users to provide parameters and get the result of a simulation in-page?

[Lee Worden]

R-Tools does a nice job with a jQuery interface - apparently it passes the parameter values from the form to the R program by defining them on the R command line in some way.

[Lee Worden]

We can do this in principle but there are unanswered design questions. We need to somehow:

• make some kind of HTTP request when the form button is pushed, which includes the parameter names and values for whatever is being submitted.
  • This might be a special form of call to Special:GetProjectFile or might be to a different target URL
• communicate the parameter names and values into the project before calling make
  • They could be exported as environment variables into the call
  • Or placed in a file of some name
  • Or something else?
• Somehow make sure the computation will happen (i.e. make won't think everything is up to date) and will have access to the values submitted
• Might there be a need to make sure the thing we just made doesn't show up later, in other places, without its context?
• Or even a privacy issue where the result of someone's computation shouldn't be visible to anyone else?

I think that I like putting the request data into a file. This works well to trigger make to redo the computation, and there can easily be make rules to transform the request data file into various formats if needed.

Right now I think the things about hiding results are probably not important, but I could be wrong about that. If needed, maybe it could be done by creating special sessions, pretty much like preview sessions, which are similarly private.