[Rd] Link to pdf documentation from other package ?

[Duncan Murdoch]

On 11/18/2009 7:28 AM, Ulrike Grömping wrote:
> Duncan Murdoch schrieb:
>> 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
>>>   
> Another thought: the link only works, if the two packages are installed 
> in the same library, doesn't it ? Would there be a way to make it work 
> independently of this restriction ?

With dynamic help, it doesn't matter where they are installed.  If you 
install the static HTML pages, then it matters.

Duncan Murdoch