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