R devel - Jul 2006 - Post CGI forms with built-in R function?

I wrote a package that requires downloading data from an external  
server based on parameters specified by the user.

I have used RMySQL or Rcurl to accomplish this, but in the interest  
of simplicity for users of this package, I'd like this communication  
to not require installing other packages and their dependencies (e.g.  
RMySQL, Rcurl, etc.).  These dependencies are sometimes a deterrent  
to using my package.

I set up a CGI script on the server to handle data requests.  Now, is  
there a *built-in* R function that could be adapted to post forms or  
otherwise allows long URLs to be passed to this script to retrieve  
the data requested.  I tried using just "scan", but it fails with  
long URLs (sometimes a long list of parameters is required).  I think  
my only option is to use POST, but it doesn't appear it is possible  
without Rcurl.

Can anyone help or suggest a "native" solution to the problem?

Thanks.

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Hi Mike

 If you don't want to have to download any packages but stick entirely
within R, then you can mimic the code in httpRequest. But,
as far as I know, there is no function in the standard R distribution to
POST an HTTP request.

  As for using
   scan("http://....")

  what is the string you are using? Are you escaping all the characters
correctly? What's the error message?

 If what you are doing involves only relatively basic HTTP requests,
perhaps the simplest thing to do is use the httpRequest package on CRAN.
It does the basics.  You may have to handle chunked responses yourself
and escaping certain characters. But that is a pure R solution that can
be easily installed via install.packages().



Mike Schaffer wrote:
> I wrote a package that requires downloading data from an external  
> server based on parameters specified by the user.
> 
> I have used RMySQL or Rcurl to accomplish this, but in the interest  
> of simplicity for users of this package, I'd like this communication  
> to not require installing other packages and their dependencies (e.g.  
> RMySQL, Rcurl, etc.).  These dependencies are sometimes a deterrent  
> to using my package.
> 
> I set up a CGI script on the server to handle data requests.  Now, is  
> there a *built-in* R function that could be adapted to post forms or  
> otherwise allows long URLs to be passed to this script to retrieve  
> the data requested.  I tried using just "scan", but it fails with
> long URLs (sometimes a long list of parameters is required).  I think  
> my only option is to use POST, but it doesn't appear it is possible  
> without Rcurl.
> 
> Can anyone help or suggest a "native" solution to the problem?
> 
> Thanks.
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
- --
Duncan Temple Lang                    duncan at wald.ucdavis.edu
Department of Statistics              work:  (530) 752-4782
4210 Mathematical Sciences Building   fax:   (530) 752-7099
One Shields Ave.
University of California at Davis
Davis,
CA 95616,
USA
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