Simple Python and Ajax Example How to Send Response with Python?
I am testing out some code with Python and Javascript trying to get an Ajax system set up. Basically I just want to input a word and have the python code send it back. Here is my html/javascript:
<html>
<head>
<title>Simple Ajax Example</title>
<script language="Javascript">
function xmlhttpPost(strURL) {
var xmlHttpReq = false;
var self = this;
// Mozilla/Safari/Chrome
if (window.XMLHttpRequest) {
self.xmlHttpReq = new XMLHttpRequest();
}
// IE
else if (window.ActiveXObject) {
self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
}
self.xmlHttpReq.open('POST', strURL, true);
self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
self.xmlHttpReq.onreadystatechange = function() {
if (self.xmlHttpReq.readyState == 4) {
updatepage(self.xmlHttpReq.responseText);
}
}
self.xmlHttpReq.send(getquerystring());
}
function getquerystring() {
var form = document.forms['f1'];
var word = form.word.value;
qstr = 'w=' + escape(word); // NOTE: no '?' before querystring
return qstr;
}
function updatepage(str){
document.getElementById("result").innerHTML = str;
}
</script>
</head>
<body>
<form name="f1">
<p>word: <input name="word" type="text">
<input value="Go" type="button" onclick='JavaScript:xmlhttpPost("/ajaxtest")'></p>
<div id="result"></div>
</form>
</body>
</html>
and here is my python:
class AjaxTest(BlogHandler):
def get(self):
user = self.get_user()
self.render('ajaxtest.html', user = user)
def post(self):
user = self.get_user()
word = self.request.get('w')
logging.info(word)
return '<p>The secret word is' + word + '<p>'
#having print instead of return didn't do anything
When I do logging the word shows up correctly and when I hardcode str in:
function updatepage(str){
document.getElementById("result").innerHTML = str;
}
It displays that correctly but right now without hardcoding it shows nothing. How am I supposed to send the response? I am using webapp2 as my Python framework and Jinja2 as the templating engine, though I don't think that has much to do with it. Do I need to send the HTTP headers?
Answer
If your problem is having difficulty returning a string from your post method, without rendering a template you can use the write method to accomplish that:
self.response.write('')
I believe you can change headers by just modifying self.response.headers