R v2.10.0: Doc clarification for cross references and where are we heading?

On 09/24/2009 12:04 PM, Duncan Murdoch wrote:

 >
 > On 24/09/2009 5:42 AM, Romain Francois wrote:

 >> On 09/24/2009 11:28 AM, Duncan Murdoch wrote:

 >>> On 23/09/2009 11:21 PM, Gabor Grothendieck wrote:

 >>>> On Wed, Sep 23, 2009 at 10:54 PM, Duncan Murdoch
 >>>> <murdoch at stats.uwo.ca> wrote:

 >>>>> - Ways to link from man pages to vignettes. The reverse would be
 >>>>> nice, but
 >>>>> it's not possible with the current design, so that would be far off.
 >>>>>

 >>>> If feasible I would like to be able to link to any text, html or pdf
 >>>> file in the package. For example, it would be nice to be able to link
 >>>> to the NEWS file and pdf files that are included in the package even
 >>>> if they are not vignettes, etc.

 >>> The \Sexpr mechanism probably allows this, though there are 

currently no

 >>> built-in support functions to help you get there. As I mentioned, that
 >>> could all be done by code in a contributed package.
 >>>
 >>> One way would be to have one help page which contains only
 >>>
 >>> \Sexpr[stage=render, results=rd]{generatePage()}
 >>>
 >>> and it will be 100% generated at render time, containing whatever you
 >>> want it to contain. (Presumably you'll have some way to communicate 

what

 >>> you want through variables that generatePage() can see.) Each time you
 >>> link to it you'll see something different.
 >>>
 >>> Duncan Murdoch

 >>
 >> Brilliant. Thanks. That solves my question as well.
 >>
 >> I did not see results = documented in ?Rd2HTML, what is allowed ?
 >> Is \Sexpr ignored when rendering other formats (tex, ...) ?
 >> or is there a way (similar to #ifdef) to only provide some content to
 >> some renderers ?

 >
 > As of yesterday, it's documented in Writing R Extensions. \Sexpr is
 > format-agnostic: it doesn't output HTML, it outputs plain text which is
 > wrapped in the appropriate HTML/LaTeX/whatever, or Rd input which is
 > processed by the whole system. So the generator would currently have to
 > use sneaky methods to figure out the format, looking at which function
 > called it, etc. I imagine in the long run we'll define some state
 > variables which the code can look at, but I'd rather see use-cases
 > before deciding what those should be.
 >
 > Duncan Murdoch

Sure. One last thing, can the \Sexpr trigger some code that redirects to 
some other page ? I suppose one could just call browseURL, but this 
would bring another tab, ...

Do I need to depend on R >= 2.10.0  if I use \Sexpr ?

Gabor, would you like to team up to generate some sort of incubator 
package to take advantage of the new system ?

Romain