Interval gets blocked with two Ajax Calls - javascript

I've got an Interval which runs a function every 3 Seconds.
intervalStepper = window.setInterval('intervalTick()','3000');
function intervalTick() {
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else {// code for IE6, IE5
xmlhttp=new ActiveXObject('Microsoft.XMLHTTP');
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status==200) {
gotResult(xmlhttp.responseText);
}
}
xmlhttp.open('GET','index.php?ajax=true',true);
xmlhttp.send();
}
function gotResult(res) {
alert(res);
}
Also, I have just another Ajax Call, which runs on button click.
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else {// code for IE6, IE5
xmlhttp=new ActiveXObject('Microsoft.XMLHTTP');
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status==200) {
agentDetailGotten(xmlhttp.responseText);
}
}
xmlhttp.open('GET','index.php?anotherPage=true',true);
xmlhttp.send();
Now, if I run the second code just in time when the interval ticks and executes the first call, the calls actually run at about the same time. But then it seems like the interval dies somehow - he doies not tick anymore.
Is this a known problem or am I just not seeing something big...
Thanks for help!

Try to clear and set your interval again:
intervalStepper = window.setInterval('intervalTick()',3000);
function intervalTick() {
window.clearInterval(intervalStepper);
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else {// code for IE6, IE5
xmlhttp=new ActiveXObject('Microsoft.XMLHTTP');
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status==200) {
gotResult(xmlhttp.responseText);
}
}
xmlhttp.open('GET','index.php?ajax=true',true);
xmlhttp.send();
intervalStepper = window.setInterval('intervalTick()',3000);
}
function gotResult(res) {
alert(res);
}

I've solved it just now.
It seems this is something like a firefox bug (found on bugzilla.mozilla.org)
NS_ERROR_NOT_AVAILABLE
This one was not shown to me, but I've just found now. It appears when Firefox tries to execute two calls at the same time.
For more Information, I found a blog entry here
I solved it that if one call is running, the other one waits.

Related

Trigger PHP function when Javascript time event activates

Is it possible to trigger a php function every minute or so using Javascript without going to another page?
You can make a loop in your PHP script and use the sleep() function.
The doc for sleep() here
Or you can do that
var milliSeconds = 6000;
setInterval( function() {
var xmlhttp;
if (window.XMLHttpRequest) // code for IE7+, Firefox, Chrome, Opera, Safari
{
xmlhttp=new XMLHttpRequest();
}
else
{
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); // code for IE6, IE5
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
console.log ( xmlhttp.responseText );
}
}
xmlhttp.open("POST","functions.php",true);
xmlhttp.send();
}, milliSeconds);
You have to load xmlhttp request object according to the browser ( xmlhttp=new XMLHttpRequest(); ), then set an event handler when the xmlhttp state changes ( xmlhttp.onreadystatechange=function() ). When it changes check if the status is 200 (success) then do whatever you want with the response. ( I printed it to console )

Combine 2 function javascript into 1 [duplicate]

This question already has an answer here:
join 2 same almost same function into 1 [closed]
(1 answer)
Closed 9 years ago.
function showRole(str,x)
{
if (str=="")
{
document.getElementById("txtHintrole"+x+"").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHintrole"+x+"").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","http://localhost/tes/index.php/form/role/"+str,true);
xmlhttp.send();
}
function showUser(str,x)
{
if (str=="")
{
document.getElementById("txtHint"+x+"").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint"+x+"").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","http://localhost/tes/index.php/form/hint/"+str,true);
xmlhttp.send();
}
can i join this 2 function into 1
because i need both of them to show data
and i dont know how to set 2 function with this
newcell.childNodes[0].setAttribute("onchange","showUser(this.value,"+xx+");");
Sure, just create a wrapper function:
var showBoth = function(str, x) {
showRole(str, x);
showUser(str, x);
};

Javascript onload two functions not returning the data

I am trying to display two javascript function when page load. But seems one is overwriting another one.
here is javascript code:
function welcome(){
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("welcome").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","php/display_welcome.php", true);
xmlhttp.send();
}
function testimonial(){
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("testimonial").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","php/display_testimonial.php", true);
xmlhttp.send();
}
window.onload = function() {
welcome();
testimonial();
};
I have 2 div id in the html page.
Also I am using IE9, when I run only one function it works fine, when run two it doesnt return the data.
Hope someone could help me.
A lot could have gone wrong:
Non-responsive server
Bad copy-pasted code
Syntax errors
etc.
Anyways, to avoid repepetive code and possible errors even if both code looks the same, I suggest you do this. Since both basically use the same operation, let's factor it out into a single reusable function:
function load(url,callback) {
var xmlhttp;
if (window.XMLHttpRequest) xmlhttp = new XMLHttpRequest();
else xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState === 4 && xmlhttp.status === 200) {
callback(xmlhttp.responseText);
}
}
xmlhttp.open('GET', url);
xmlhttp.send();
}
window.onload = function () {
load('php/display_welcome.php',function(response){
document.getElementById("welcome").innerHTML = response;
});
load('php/display_testimonial.php',function(response){
document.getElementById("testimonial").innerHTML = response;
});
};
You declared xmlhttp without var which gives it global scope, that is why it gets over written when you call the second function. Declare it locally and that will not happen. Use var and declare it locally.
var xmlhttp;

Adding data to a div called from JS

I have a simple script im testing which calls a HTML file. In that html file is a div with the id "test2".
I am then trying to add content to its innerHTML but it acts like it don't exist, even though the div shows in the browser.
This is how I have approached the idea:
<script>
function call_file(file,div_id){
var xmlhttp;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById(div_id).innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET",file,true);
xmlhttp.send();
}
window.onload = function() {
file = 'test.html';
div_id = 'test';
call_file(file,div_id);
document.getElementById('test2').innerHTML = 'Hi';
};
</script>
<div id="test" class="outer""></div>
Content of "test.html":
<div id="test2" class="inner"></div>
Why does it not find id "test2" with this error, even though i see the div with my own eyes:
Cannot set property 'innerHTML' of null
You're making an asynchronous call, so send() will return before the response is received and added into the DOM. Any code that depends on the received data should be in your onreadystatechange function, or somehow triggered by it, so that it won't execute until the response data has been received.
You Cannot set it because it doesn't exist, yet. You need to wait until it's loaded.
You can do that with a callback function.
function call_file(file,div_id, callback){
var xmlhttp;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById(div_id).innerHTML=xmlhttp.responseText;
return callback();
}
}
xmlhttp.open("GET",file,true);
xmlhttp.send();
}
window.onload = function() {
file = 'test.html';
div_id = 'test';
call_file(file,div_id, function () {
document.getElementById('test2').innerHTML = 'Hi';
});
};

how to fetch a dynamic link of rss feed?

I try to fetch a dynamic link of rss feed from skydrive using xmlhttp:
...
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
//this is the feed:
var url = "https://skydrive.live.com/feed.aspx?cid=1F8A5680599AFFF9&resid=1F8A5680599AFFF9%21120";
xmlhttp.open("GET",url,false);
xmlhttp.send();
xmlDoc=xmlhttp.responseXML;
...
but it doesn't work - what did I do wrong? and how should I fix it?
thanks
You haven't provided a callback function for the success of your ajax call. Provide one.
xmlhttp.onreadystatechange=function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
alert(xmlhttp.responseText)
}
You can also hook into the error event of XMLHttpRequest object to see what's going wrong.

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