[Rd] Link to pdf documentation from other package ?

[Duncan Murdoch]

Ulrike Groemping wrote:
>
> Duncan Murdoch-2 wrote:
>   
>> Ulrike Groemping wrote:
>>     
>>> Dear developeRs,
>>>
>>> I have not found anything recent about how to link to a vignette or other
>>> documentation from within Rd-files. Is this now possible with the new
>>> help
>>> system ? For example, I would like to link to the file AlgDesign.pdf
>>> provided within the doc directory of package AlgDesign.
>>>
>>>   
>>>       
>> Yes, you can do it with a \url{} macro.  Use a relative link, acting as 
>> though the starting page is located in /library/AlgDesign/html/*.  So 
>> \url{../doc/AlgDesign.pdf}
>> should work from the same package, 
>> \url{../../AlgDesign/doc/AlgDesign.pdf} from elsewhere.  Please let me 
>> know if this doesn't work, I haven't tested.
>>
>> Duncan Murdoch
>>
>>     
>
> Yes, this works, thanks! Is it also possible to display an alternative text
> instead of the URL itself, like with other links (e.g. show text "Open pdf"
> that operates the link) ?
>
>   

There's no optional text in the \url{} tag, but you could embed it in an 
\ifelse tag, e.g.

\ifelse{html}{\url{ ....  }}{ [open pdf ...] }

might work.  Using the \ifelse tag will make your package depend on R >= 
2.10.0.

Duncan Murdoch
>