# A chat-like program for R.
library('websockets')
library('RJSONIO')
htmldata = 'R Chat
R Chat
Console:
'
port = 7681
w = create_server(webpage=static_text_service(htmldata), port=port)
f = function(DATA,WS,...)
{
d = tryCatch(rawToChar(DATA),error=function(e) "")
jpeg(file=itmp, width=400,height=400,quality=100)
devAskNewPage(ask=FALSE)
sink(file=ctmp,split=TRUE)
ans = tryCatch(capture.output(eval(parse(text=d),envir=globalenv())),
error = function(e) cat(as.character(e),file=ctmp))
dev.off()
sink()
ans = paste(ans,collapse="\n")
if(file.exists(itmp)) {
p = base64encode(readBin(itmp,what="raw",n=1e6))
p = paste("data:image/jpg;base64,\n",p,sep="")
msg = sprintf("Client %d says: %s\n%s",WS$socket,d,ans)
websocket_broadcast(toJSON(list(msg=msg, fig=p)),WS$server)
} else {
msg = sprintf("Client %d says: %s\n%s",WS$socket,d,ans)
websocket_broadcast(toJSON(list(msg=msg)),WS$server)
}
}
set_callback("receive",f,w)
ctmp = tempfile()
itmp = tempfile()
cat(sprintf("Direct browsers to http://%s:%s\n",Sys.info()["nodename"],port))
while(TRUE) service(w)