Download and save/pull from save mapping

[muschellij2]

Given how NHANES links move around, it would be nice to be able to use nhanesTranslate to download the mapping or pull from a local file if available.

[deepayan]

I think you are trying to solve two different problems with your patch. For the first one, when you have a local copy already available, you can already do

rawdata <- foreign::read.xport("/path/to/DEMO_G.XPT")
cb <- nhanesCodebookFromURL("/path/to/DEMO_G.htm")
nhanesA:::raw2translated(rawdata, codebook = cb)

Now, raw2translated() is not exported, so it would make sense to ask for the same functionality from nhanesTranslate(). The correct solution there, in my view, would be to add a new argument codebook (similar to data) so that we can call

nhanesTranslate(data = rawdata, codebook = cb)

I will be happy to implement this if @cjendres1 thinks it is reasonable.

The other problem you are trying to solve is to use nhanesTranslate() to save the downloaded file for later use. I think that's the wrong place to do it. If you want to create a mirror of the CDC website, there are better ways to do it, and then httpuv can be easily used to serve it locally. nhanesA already has tools to support local / alternative mirrors via environment variables; see here for details.

[muschellij2]

I think the codebook addition is what I'm looking for. I think running a full on http server to read in a relatively static HTML, however, seems like a bit of overkill for most users, who want to download the html. It seems like you have to download them yourselves because the internals of nhanesTranslate provides the mapping of the nh_table to the HTML correct?

[cjendres1]

Deepayan, I agree with your solution to add the codebook argument.