For some reason i just cannot get this to work, the user enters a comment and it sends it to the database - I was getting so stressed that I just made the script send a straight forward line to the database -
var params = "comm=hello&subject=binny";
rather than what's in the text box, so ignore that!
Here's what i have so far
<script>
function newComment()
{
var url = "leavecomment.php";
var params = "comm=hello&subject=binny";
http.open("POST", url, true);
//Send the proper header information along with the request
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http.setRequestHeader("Content-length", params.length);
http.setRequestHeader("Connection", "close");
http.onreadystatechange = function() {//Call a function when the state changes.
if(http.readyState == 4 && http.status == 200) {
alert(http.responseText);
}
}
http.send(params);
}
1) Where is http defined? You'll have to show the code for it (also what browser are you testing in)
2) You are setting two headers I don't normally see. Content-length and Connection. Any particular reason?
Other than that at first glance it looks about right.
david_kw
Hey sorry, extremely stupic mistake, I defined http and now it works fine :)
The only thing is, It wont give me a response, this is just a call to another script where it echos all the information from the database, everything gets written to the datbase but nothing gets returned:
function createRequestObject(){
var request_o;
var browser = navigator.appName;
if(browser == "Microsoft Internet Explorer"){
request_o = new ActiveXObject("Microsoft.XMLHTTP");
}else{
request_o = new XMLHttpRequest();
}
return request_o;
}
function newComment()
{
var http = createRequestObject();
var url = "leavecomment.php";
var params = "comm=hello&subject=binny";
http.open("POST", url, true);
//Send the proper header information along with the request
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http.setRequestHeader("Content-length", params.length);
http.setRequestHeader("Connection", "close");
http.onreadystatechange = function() {//Call a function when the state changes.
if(http.readyState == 4 && http.status == 200) {
showComments();
}
}
http.send(params);
}
function showComments()
{
var http = createRequestObject();
var url = 'callcomment.php';
http.open("GET", url);
var response = http.responseText;
document.getElementById('existing_comments').innerHTML = response;
}
A couple things. One thing you could test for is the status of the response. So add this to your callback function.
if(http.readyState == 4 && http.status != 200) {
alert("Got a bad response status of " + http.status);
}
The other thing I notice in your showComments() function is that it doesn't set a call back function. I believe the default is asynchronous communication so if you want to do it without a callback you'd have to explicitly say false for the 3rd parameter of open().
http.open("GET", url, false);
david_kw
I added the alert and added the "false".
The alert doesn't give any response, any ideas?
Try this in your handler to see if the browser is getting any return and what kind.
http.onreadystatechange = function() {//Call a function when the state changes.
if (http.readyState == 4) {
alert("status = '" + http.status + "'");
alert("response = '" + http.responseText + "'");
if (http.status == 200) {
showComments();
}
}
}
That should find out if the problem is in the post or the get portion of the code.
david_kw
i get
"status = '200'"
"response = ''"
but also, from the leavecomment.php script there isn't any response, it's just a script that inserts the text into the database
Still not quite sure what to do though
Thanks for all your help so far :)
Ahh ok. So post is working as expected.
Try changing showComments()
function showComments()
{
var http = createRequestObject();
var url = 'callcomment.php';
http.open("GET", url, false);
alert("status = '" + http.status + "'");
alert("response = '" + http.responseText + "'");
var response = http.responseText;
document.getElementById('existing_comments').innerHTML = response;
}
david_kw
I added that, and I dont get any alerts at all :S
Hmm, not a good sign. :)
So are you getting a javascript error?
I wonder if the problem is you are calling to set up another http request while you are still in a handler for another one. I don't see why it would be a problem, but maybe.
how about changing the post handler again to this.
http.onreadystatechange = function() {//Call a function when the state changes.
if (http.readyState == 4) {
if (http.status == 200) {
setTimeout(showComments, 0);
}
}
}
Basically what that does is immediately generate an event to call showComments() when all other current events are handled.
What browser are you testing in again?
david_kw
Ok, I'm an idiot. I just noticed a problem. You weren't calling http.send(null); in your showComments() function.
function showComments()
{
var http = createRequestObject();
var url = 'callcomment.php';
http.open("GET", url, false);
http.send(null);
alert("status = '" + http.status + "'");
alert("response = '" + http.responseText + "'");
var response = http.responseText;
document.getElementById('existing_comments').innerHTML = response;
}