将Webpy与AJAX结合使用

Question

I am relatively new to web development and am trying to get the client javascript to send GET requests to a python script running on the server and the server to return data based on that request. I have tried adapting the examples of the webpy library I found online to no avail. Whenever a GET request is sent, the responseText attribute of XMLHttpRequest() returns the text of the python file rather than the data. Any advise would be much appreciated!

The javascript function:

function sendSerialCommand(selection, command) {
    var xmlhttp = new XMLHttpRequest();

    xmlhttp.onreadystatechange = function () {
        if (xmlhttp.readyState === 4 && xmlhttp.status === 200) {
            if (command !== 5) {
                document.getElementById("output2").innerHTML = xmlhttp.responseText;
                document.getElementById("output2").style.color = "green";
            } else {
                document.getElementById("output1").innerHTML = xmlhttp.responseText;
                console.log(xmlhttp.responseText);
                document.getElementById("output1").style.color = "green";
            }
        }
    };

    xmlhttp.open("GET", pythonFileName + "?sel=" + selection + "?cmd=" + command, true);
    xmlhttp.send();
}

...and the test python script:

import web

urls = (
    '/', 'Index'
)
app = web.application(urls,globals())

#MAIN LOOP

class Index:
    def GET(self):
        webInput = web.input()
        return 'message: GET OK!'

if __name__ == "__main__":
        app.run()

Answer 1

The trick was to use the CGI library for python as such:

#!/usr/bin/python

# Import modules for CGI handling 
import cgi, cgitb 

# Create instance of FieldStorage 
form = cgi.FieldStorage() 

# Get data from fields
first_name = form.getvalue('cmd')
last_name  = form.getvalue('sel')

print "Content-type:text/html

"
print "Hello %s %s" % (first_name, last_name)

This captures the keys and data from the GET request and the print command returns data to the xmlhttp.responseText attribute on the client-side.

The script has to be placed into a file the websever is able to execute the script from. That is usually the default /cgi-bin folder located in either /var/www or /etc.