I use newLISP as local http server on Windows platform:
newlisp.exe -c -d 1235
It is possible send some string (like "(+ 2 3)") from Javascript to newLISP session
for evaluate and get back answer?
Don't know. Wouldn't that be a security problem?
It should be possible to do this from JavaScript. Connect to port 1235 and send the string "(+ 3 4)n", then wait for an answer which should be "7n" (7 plus line-feed). And yes, there is a big potential for security problems; so carefully check each string received for evaluation.
Thanks you for reply.
I am beginner in newLisp and Javascritp.
Please, give me an example.
I try run newlisp:
newlisp.exe. -c -d 8080
and open in browser this document:
<html>
<body>
<h3>newLISP server and JS demo</h3>
<script type="text/javascript" language="javascript">
if (window.XMLHttpRequest) {
xmlHttp = new XMLHttpRequest();
} else if (window.ActiveXObject) {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
function newLispEval(expr) {
xmlHttp.open("GET", "http://localhost:8080", false);
try {
xmlHttp.send(expr);
} catch (e) { alert(e.message); }
return xmlHttp.responseText;
}
var answer = newLispEval("(+ 3 4)n");
document.write(answer);
document.write("<BR>ok.");
</script>
</body>
</html>
<!-- end of file -->
but get NS_ERROR_FAILURE for "xmlHttp.send(expr);"
Sorry, misprint:
I run newLISP with line:
newlisp.exe -c -d
Sorry again :)
newlisp.exe -c -d 8080
newLISP when started: newlisp -c -d 8080, answers to two different protocols. What I was demonstrating is the simple command line protocol, but xmlHttp.open() is using the HTTP protocol.
So with: newlisp -c -d 8080, the newLISP server handles the HTTP protocol too. But you would need to initiate some kind of CGI process and pass the expression to evaluate as a parameter in a GET or POST request.
Cormullion is doing this here:
http://unbalanced-parentheses.nfshost.com/lambdalator/index
If your emphasis is on asynchronous update then look at this example:
http://www.newlisp.org/index.cgi?page=AJAX_and_newLISP
You could merge both approaches passing the expression to evaluate as parameter in the xmlHttp GET request.
Sorry for long silent.
I create file "eval.cgi":
#!/usr/bin/newlisp
(define (url-translate str)
(replace "%([0-9A-F][0-9A-F])" str (format "%c" (int (append "0x" $1))) 1))
(print "Content-type: text/htmlrnrn")
(print (eval-string (url-translate (env "QUERY_STRING"))))
(exit)
# end of file
and file "test1.html":
<html>
<body>
<h3>newLISP server and JS demo</h3>
<script type="text/javascript" language="javascript">
if (window.XMLHttpRequest) {
xmlHttp = new XMLHttpRequest();
} else if (window.ActiveXObject) {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
function newLispEval(expr) {
xmlHttp.open("GET", "eval.cgi?" + expr, false);
try {
xmlHttp.send(null);
} catch (e) { alert(e.message); }
return xmlHttp.responseText;
}
var answer;
answer = newLispEval("(+ 3 4)");
document.write(answer);
document.write("<BR>ok.");
</script>
</body>
</html>
<!-- end of file -->
then I run
and open browser for location:
and... it's work!
Thanks you.
But I still have some small problems:
1. Newlisp session not saved between requests:
after
evaluation of
give me error "ERR: value expected in function + : x".
It is possible work form Javascript with one newlisp session?
2. Newlisp in server mode not support names with spaces?
Location like:
Quote
not work for me.
3. It is possible explicit specify Windows drive letter in location?
Location like:
Quote
not work for me.
Sorry, misprint:
instead
"newLispEval("(+ 'x 4)");"
must be
"newLispEval("(+ x 4)");"
Quote
You could save the session doing a (save "session.lsp") in the CGI program after evaluating and doing (load "session.lsp") at the beginning of each CGI process.
But a better/faster solution would be to start a second newlisp server process, which stays in memory, and use 'net-eval' to connect from it from the CGI process. newLISP processes use very little memory, so starting just another one is the preferred solution. It is also the more secured solution, because you could preload the serve with statements disabling all dangerous commands. E.g:
Quote
Currently not supported. newLISP server mode is not meant to be a full featured web server, it doesn't do any URL back translation.
Quote
Drive switching works like this on Windows:
If D would be the current drive, you could do:
This is suitable for me.
Many thanks!