Safe version of glue

[jimhester]

It would be useful to have a safe version of glue that did not evaluate arguments, only looked them up with get(). This way glue could be used in shiny apps and similar places without concern. It is of course possible to do this already with a custom transformer, but it seems a common enough case we should probably have a new function for it.

[jcheng5]

@rich-iannone and I ended up needing something like this for a package that needs "safe glue" in a bunch of places, and discovered that .transformer = base::get actually works nicely!

However, I totally agree that a first-class glue function that works this way would be fantastic--the idea that people might be using regular glue::glue with Shiny is terrifying!

[jimhester]

I didn't realize the pos argument to get() also takes environments, so yeah .transformer = base::get seems like a solution. I also didn't see this response until after posting my reply in the other thread, apologies for telling you something you had already done!

[jimhester]

I will add a glue_safe() function using get() in the next CRAN release of glue.

[jcheng5]

Along similar lines, can I also request for glue_data to treat envir = NULL like envir = emptyenv()? (Not sure what you'd want to do with glue(envir = NULL).)

Because the other "gotcha" we've had with glue for package development is intending to operate on user data (i.e. glue_data(.x = ...)) but accidentally including local/lexical scope (i.e. the variables belonging to the package).

[jimhester]

Closed by 46a3ee3