Develop Reference

Ajax function with a Form variable

What is wrong with this ajax function.
<script>
function loadDoc() {
var a=document.data.fitem.value;
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("demo").innerHTML = this.responseText;
}
};
xhttp.open("GET", "master_find.jsp?val="+a) ;
xhttp.send();
}
</script>
I tried so many ways to supply a variable to the master_find.jsp script to retrieve the main item from a table., no success.

Multiple Ajax calls sometimes fail

I have a PHP script which queries a database and returns a table, depending on the input, e.g.results.php?f=1.
I am trying to call it multiple times from JavaScript:
function go(n,divid) {
document.getElementById(divid).innerHTML = "<img src=\"load.gif\">";
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById(divid).innerHTML = xmlhttp.responseText;
}
}
xmlhttp.open("GET", n, true);
xmlhttp.send();
}
Call later
go('results.php?print=1&nh=1','d1');
go('results.php?print=2&nh=1','d2');
go('results.php?print=3&nh=1','d3');
go('results.php?print=4&nh=1','d4');
The PHP code connects to a SQLite3 database. The problem with the above is that sometimes it works, but sometimes one of the queries fails to be prepared by SQLite3::prepare().
What could be wrong? A sqlite race condition? A javascript issue?
When results.php is called just once, the query always succeeds.
Thanks.

Use xhttp instead of xmlhttp.
function go(n,divid) {
var xhttp = new XMLHttpRequest();
document.getElementById(divid).innerHTML = "<img src=\"load.gif\">";
xhttp.onreadystatechange = function () {
if (xhttp.readyState == 4 && xhttp.status == 200) {
document.getElementById(divid).innerHTML = xhttp.responseText;
}
}
xhttp.open("GET", n, true);
xhttp.send();
}
go('results.php?print=1&nh=1','d1');

DIV changing onclick with external page as a variable

I have this code that is changing the content of the DIV based on an external page:
external page
and
function loadexternalPage() {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById('main_frame').innerHTML =
xmlhttp.responseText;
}}
xmlhttp.open("GET", "externalpage.html", true);
xmlhttp.send();
}
How can I update this code in the way the function get a variable as an external page instead?
something like this??
Link to external page
function loadexternalPage(externalpage) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById('main_frame').innerHTML = xmlhttp.responseText;
} }
xmlhttp.open("GET", externalpage, true);
xmlhttp.send();
}
or with method:
$(document).ready(function () {
loadxtPage("popup.html");
$("#main_frame").click(loadxtPage("externalpage.html"));
})

You can use the href attribute:
Pass the event here:
Link to external page
Use the events' attribute to get the URL:
function loadexternalPage(event) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById('main_frame').innerHTML = xmlhttp.responseText;
}
}
xmlhttp.open("GET", event.target.href, true);
xmlhttp.send();
}
This is one possible solution. It really depends on where you need to specify the URL.

Timeout method after hitting the url

We have the following method to invoke the URL using ajax.
Currently after hitting the url we are using the response.
So we want to put a timeout for reposne.So when we invoke the url if the response didn't came after 2sec then call one more method and if resp comes within two seconds call other mehtod.
We have tried using the timeout,but unable to made it working with the code.
function ajaxCall(url1) {
var ajaxresp = null;
var xmlhttp;
if (window.XMLHttpRequest) {
xmlhttp = new XMLHttpRequest();
} else {
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.open("GET", url1, true);
xmlhttp.send();
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4) {
if (xmlhttp.status == 200) {
ajaxresp = xmlhttp.responseText;
//function call
getAdResponse(ajaxresp);
}
}
}
}
Please advice me how to proceed.

Try smth like this
xmlhttp.open("GET",url1,true);
xmlhttp.onreadystatechange= function (){
if (xmlhttp.readyState==4){
if (xmlhttp.status == 200){
ajaxresp = xmlhttp.responseText;
}
}
xmlhttp.send();
setTimeout(function() {
if(ajaxresp) {
dosmth(ajaxresp);
} else {
dosmthelse();
}
}, 2000);

ajax error only first request is send

$('#show_mess').click(function (){
$('#dropdown_mess').slideToggle("slow");
$('#arrow_mess').slideToggle("slow");
$('#arrow_not').hide("slow");
$('#dropdown_not').hide("slow");
function recall(){ setTimeout(function () {
xmlhttp = new XMLHttpRequest();
xmlhttp.open("GET", "http://localhost/ajax/mess_data.php", true);
xmlhttp.onreadystatechange = function () {
if(xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById('dropdown_mess').innerHTML = xmlhttp.responseText;
}
}
xmlhttp.send();
document.getElementById('dropdown_mess').innerHTML = "<img class='non_auto' id='ajax_loading' src='img/ajax_loading.gif'></img>";
recall();
}, 2000);
};
recall();
});
this function works fine but when each ajax call is done i need to colse and re-oper chrome in order to work, works fine in firefox

You are already using Jquery so why don't you try it's ajax function like below
$.ajax({
url: "test.html",
context: document.body
}).done(function() {
....
});
You can find more information on the manual