I would like to test if the ajax request is identical so it can be aborted or some other alert action taken?
In reality clients can change the request via a few form elements then hit the refresh button.
I have made a poor attempt at catching the identical request. Need to keep the timer refresh functionality.
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript">
var current_request_id = 0;
var currentRequest = null;
var lastSuccessfulRequest = null;
function refreshTable() {
$('#select').html('Loading');
window.clearTimeout(timer);
//MY CATCH FOR DUPLICATE REQUEST NEEDS WORK
if (lastSuccessfulRequest == currentRequest)
{
//currentRequest.abort();
alert('Duplicate query submitted. Please update query before resubmission.');
}
var data = {
"hide_blanks": $("#hide_blanks").prop('checked'),
"hide_disabled": $("#hide_disabled").prop('checked'),
};
json_data = JSON.stringify(data);
current_request_id++;
currentRequest = $.ajax({
url: "/calendar_table",
method: "POST",
data: {'data': json_data},
request_id: current_request_id,
beforeSend : function(){
if(currentRequest != null) {
currentRequest.abort();
}
},
success: function(response) {
if (this.request_id == current_request_id) {
$("#job_table").html(response);
$("#error_panel").hide();
setFixedTableHeader();
}
},
error: function(xhr) {
if (this.request_id == current_request_id) {
$("#error_panel").show().html("Error " + xhr.status + ": " + xhr.statusText + "<br/>" + xhr.responseText.replace(/(?:\r\n|\r|\n)/g, "<br/>"));
}
},
complete: function(response) {
if (this.request_id == current_request_id) {
$("#select").html("Refresh");
window.clearTimeout(timer);
stopRefreshTable();
window.refreshTableTimer = window.setTimeout(refreshTable, 10000);
lastSuccessfulRequest = currentRequest;
}
}
});
}
//TIMER STUFF TO refreshTable()
//THIS SECTION WORKS FINE
var startDate = new Date();
var endDate = new Date();
var timer = new Date();
function startRefreshTable() {
if(!window.refreshTableTimer) {
window.refreshTableTimer = window.setTimeout(refreshTable, 0);
}
}
function stopRefreshTable() {
if(window.refreshTableTimer) {
self.clearTimeout(window.refreshTableTimer);
}
window.refreshTableTimer = null;
}
function resetActive(){
clearTimeout(activityTimeout);
activityTimeout = setTimeout(inActive, 300000);
startRefreshTable();
}
function inActive(){
stopRefreshTable();
}
var activityTimeout = setTimeout(inActive, 300000);
$(document).bind('mousemove click keypress', function(){resetActive()});
</script>
<input type="checkbox" name="hide_disabled" id="hide_disabled" onchange="refreshTable()">Hide disabled task<br>
<br><br>
<button id="select" type="button" onclick="refreshTable();">Refresh</button>
I'd use the power of .ajaxSend and .ajaxSuccess global handlers.
We'll use ajaxSuccess to store a cache and ajaxSend will try to read it first, if it succeeds it will trigger the success handler of the request immediately, and abort the request that is about to be done. Else it will let it be...
var ajax_cache = {};
function cache_key(settings){
//Produce a unique key from settings object;
return settings.url+'///'+JSON.encode(settings.data);
}
$(document).ajaxSuccess(function(event,xhr,settings,data){
ajax_cache[cache_key(settings)] = {data:data};
// Store other useful properties like current timestamp to be able to prune old cache maybe?
});
$(document.ajaxSend(function(event,xhr,settings){
if(ajax_cache[cache_key(settings)]){
//Add checks for cache age maybe?
//Add check for nocache setting to be able to override it?
xhr.abort();
settings.success(ajax_cache[cache_key(settings)].data);
}
});
What I've demonstrated here is a very naïve but functional approach to your problem. This has the benefit to make this work for every ajax calls you may have, without having to change them. You'd need to build up on this to consider failures, and to make sure that the abortion of the request from a cache hit is not getting dispatched to abort handlers.
One valid option here is to JSON.Stringify() the objects and compare the strings. If the objects are identical the resulting serialised strings should be identical.
There may be edge cases causing slight differences if you use an already JSONified string directly from the response so you'll have to double check by testing.
Additionally, if you're trying to figure out how to persist it across page loads use localStorage.setItem("lastSuccessfulRequest", lastSuccessfulRequest) and localStorage.getItem("lastSuccessfulRequest"). (If not, let me know and I'll remove this.)
i am try to load B.php from A.php after execution in the function and pass some data using a post array from A.php to B.php within same time.
code list as follows
A.php
<script type="text/javascript">
alert_for_the_fucntion();
window.location.href = "B.php";
function alert_for_the_fucntion() {
$.post("B.php", {action: 'test'});
}
</script>
B.php
<?php
if (array_key_exists("action", $_POST)) {
if ($_POST['action'] == 'test') {
echo 'ok';
}
}
?>
for testing purpose i tried to echo something in the B.php. but currently this is not working. have i done any mistakes? or is there any possible method to do this.
Your code does this:
Tells the browser to navigate to B.php (using a GET request)
Triggers a POST request using XMLHttpRequest
The POST request probably gets canceled because the browser immediately leaves the page (and the XHR request is asynchronous). If it doesn't, then the response is ignored. Either way, it has no effect.
You then see the result of the GET request (which, obviously, doesn't include $_POST['action']) displayed in the browser window.
If you want to programmatically generate a POST request and display the result as a new page then you need to submit a form.
Don't use location. Don't use XMLHttpRequest (or anything that wraps around it, like $.ajax).
var f = document.createElement("form");
f.method = "POST";
f.action = "B.php";
var i = document.createElement("input");
i.type = "hidden";
i.name = "action";
i.value = "test";
f.appendChild(i);
document.body.appendChild(f);
f.submit();
If you want to process the results in JavaScript then:
Don't navigate to a different page (remove the line using `location)
Add a done handler to the Ajax code
e.g.
$.post("B.php", {action: 'test'}).done(process_response);
function process_response(data) {
document.body.appendChild(
document.createTextNode(data)
);
}
Try this:
Javascript:
<script type="text/javascript">
window.onload = alert_for_the_fucntion;
function alert_for_the_fucntion() {
$.post("B.php",
{
action: 'test'
},
function(data, status){
if(status=="success"){
alert(data);
}
}
);
}
</script>
PHP
<?php
if(isset($_POST['action'])){
echo $_POST['action'];
}
?>
So i have written a function that is called onclick in my html file that uses AJAX, but i would like for this post to go to a specific table in mysql.
$('#submitIFC').click(function(e) {
var request;
if (window.XMLHttpRequest) {
request = new XMLHttpRequest();
} else {
request = new ActiveXObject("Microsoft.XMLHTTP");
}
var opinionIFC = $('ul.sort').sortable('toArray').join(',');
request.onreadystatechange = function() {
if ((request.readyState===4) &&(request.status===200)) {
var return_data = request.responseText;
document.getElementById('rank_ul').innerHTML= 'return_data';
// Preventing the default action triggered by clicking on the link
e.preventDefault();
e.preventDefault();
}//end of if
}//end of onreadystatechange function
//send requested movie to php file which will send to the external server
request.open("POST", "results.php", true);
request.send(opinionIFC);
document.getElementById('rank_ul').innerHTML='<img src="ajax-loader.gif">';
});
however there seems to be an issue with connecting this to my php if conditional, i tried copying the contents on my request.send(), like so
if($_POST['opinionIFC'])
{echo
// The data arrives as a comma-separated string,
// so we extract each post ids:
$data=explode(',',str_replace('li','',$_POST['sortdata']));
// Getting the number of objects
list($tot_objects) = mysql_fetch_array(mysql_query("SELECT COUNT(*) FROM sort_objects"));
if(count($data)!=$tot_objects) die("Wrong data!");
foreach($data as $k=>$v)
{
// Building the sql query:
$str[]='('.(int)$v.','.($tot_objects-$k).')';
}
$str = 'VALUES'.join(',',$str);
// This will limit voting to once a day per IP:
mysql_query(" INSERT INTO `sort_votes` (ip,date_submit,dt_submit)
VALUES ('".$_SERVER['REMOTE_ADDR']."',NOW(),NOW())");
// If the user has not voted before today:
if(mysql_affected_rows($link)==1)
{
mysql_query(' INSERT INTO `sort_objects` (id,votes) '.$str.'
ON DUPLICATE KEY UPDATE votes = votes+VALUES(votes)');
}
}
why isnt the ajax post request filtering through to my php file?
thank you so much, any help is much appreciated.
You're not sending opinionIFC parameter, try:
request.send('opinionIFC=' + opinionIFC);
You also need to set Content-type
request.setRequestHeader("Content-type","application/x-www-form-urlencoded");
Basically, I want to have an interactive button on my website, that, when clicked, sends some data to the server in order to be checked and display the response (without form sending / page reload).
I thought it would be something like:
function checkData()
{
var req = new XMLHttpRequest();
var conf = document.getElementById('my_text_area').value;
req.open("GET", 'check_data', true);
req.onreadystatechange = function ()
{
var pre = document.getElementById('check_data_out');
pre.innerHTML = req.responseText;
}
req.send(conf);
return false;
}
And on the server side:
#get('/check_data')
def check_data():
# Process the content and answer something...
content = str(request.is_ajax) + ' - ' + str(request.GET) + ' - ' + str(request.POST)
return content
But this obviously doesn't work. Either it is not the right way to send data via javascript or not the right way to access it in bottle.py.
Showing me how it works is highly appreciated.
You can use dojo for client side logic.
var button = dojo.byId('button_id'); // button_id refers to the id of the button you want to click
dojo.connect(button,'onclick',dojo.xhrGet({
url: '/check_data',
handleAs : 'text',
load : function(response){
dojo.byId('button_id').innerHTML = response;
}
}));
I'm making a web app that requires that I check to see if remote servers are online or not. When I run it from the command line, my page load goes up to a full 60s (for 8 entries, it will scale linearly with more).
I decided to go the route of pinging on the user's end. This way, I can load the page and just have them wait for the "server is online" data while browsing my content.
If anyone has the answer to the above question, or if they know a solution to keep my page loads fast, I'd definitely appreciate it.
I have found someone that accomplishes this with a very clever usage of the native Image object.
From their source, this is the main function (it has dependences on other parts of the source but you get the idea).
function Pinger_ping(ip, callback) {
if(!this.inUse) {
this.inUse = true;
this.callback = callback
this.ip = ip;
var _that = this;
this.img = new Image();
this.img.onload = function() {_that.good();};
this.img.onerror = function() {_that.good();};
this.start = new Date().getTime();
this.img.src = "http://" + ip;
this.timer = setTimeout(function() { _that.bad();}, 1500);
}
}
This works on all types of servers that I've tested (web servers, ftp servers, and game servers). It also works with ports. If anyone encounters a use case that fails, please post in the comments and I will update my answer.
Update: Previous link has been removed. If anyone finds or implements the above, please comment and I'll add it into the answer.
Update 2: #trante was nice enough to provide a jsFiddle.
http://jsfiddle.net/GSSCD/203/
Update 3: #Jonathon created a GitHub repo with the implementation.
https://github.com/jdfreder/pingjs
Update 4: It looks as if this implementation is no longer reliable. People are also reporting that Chrome no longer supports it all, throwing a net::ERR_NAME_NOT_RESOLVED error. If someone can verify an alternate solution I will put that as the accepted answer.
Ping is ICMP, but if there is any open TCP port on the remote server it could be achieved like this:
function ping(host, port, pong) {
var started = new Date().getTime();
var http = new XMLHttpRequest();
http.open("GET", "http://" + host + ":" + port, /*async*/true);
http.onreadystatechange = function() {
if (http.readyState == 4) {
var ended = new Date().getTime();
var milliseconds = ended - started;
if (pong != null) {
pong(milliseconds);
}
}
};
try {
http.send(null);
} catch(exception) {
// this is expected
}
}
you can try this:
put ping.html on the server with or without any content, on the javascript do same as below:
<script>
function ping(){
$.ajax({
url: 'ping.html',
success: function(result){
alert('reply');
},
error: function(result){
alert('timeout/error');
}
});
}
</script>
You can't directly "ping" in javascript.
There may be a few other ways:
Ajax
Using a java applet with isReachable
Writing a serverside script which pings and using AJAX to communicate to your serversidescript
You might also be able to ping in flash (actionscript)
You can't do regular ping in browser Javascript, but you can find out if remote server is alive by for example loading an image from the remote server. If loading fails -> server down.
You can even calculate the loading time by using onload-event. Here's an example how to use onload event.
Pitching in with a websocket solution...
function ping(ip, isUp, isDown) {
var ws = new WebSocket("ws://" + ip);
ws.onerror = function(e){
isUp();
ws = null;
};
setTimeout(function() {
if(ws != null) {
ws.close();
ws = null;
isDown();
}
},2000);
}
Update: this solution does not work anymore on major browsers, since the onerror callback is executed even if the host is a non-existent IP address.
To keep your requests fast, cache the server side results of the ping and update the ping file or database every couple of minutes(or however accurate you want it to be). You can use cron to run a shell command with your 8 pings and write the output into a file, the webserver will include this file into your view.
The problem with standard pings is they're ICMP, which a lot of places don't let through for security and traffic reasons. That might explain the failure.
Ruby prior to 1.9 had a TCP-based ping.rb, which will run with Ruby 1.9+. All you have to do is copy it from the 1.8.7 installation to somewhere else. I just confirmed that it would run by pinging my home router.
There are many crazy answers here and especially about CORS -
You could do an http HEAD request (like GET but without payload).
See https://ochronus.com/http-head-request-good-uses/
It does NOT need a preflight check, the confusion is because of an old version of the specification, see
Why does a cross-origin HEAD request need a preflight check?
So you could use the answer above which is using the jQuery library (didn't say it) but with
type: 'HEAD'
--->
<script>
function ping(){
$.ajax({
url: 'ping.html',
type: 'HEAD',
success: function(result){
alert('reply');
},
error: function(result){
alert('timeout/error');
}
});
}
</script>
Off course you can also use vanilla js or dojo or whatever ...
If what you are trying to see is whether the server "exists", you can use the following:
function isValidURL(url) {
var encodedURL = encodeURIComponent(url);
var isValid = false;
$.ajax({
url: "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22" + encodedURL + "%22&format=json",
type: "get",
async: false,
dataType: "json",
success: function(data) {
isValid = data.query.results != null;
},
error: function(){
isValid = false;
}
});
return isValid;
}
This will return a true/false indication whether the server exists.
If you want response time, a slight modification will do:
function ping(url) {
var encodedURL = encodeURIComponent(url);
var startDate = new Date();
var endDate = null;
$.ajax({
url: "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22" + encodedURL + "%22&format=json",
type: "get",
async: false,
dataType: "json",
success: function(data) {
if (data.query.results != null) {
endDate = new Date();
} else {
endDate = null;
}
},
error: function(){
endDate = null;
}
});
if (endDate == null) {
throw "Not responsive...";
}
return endDate.getTime() - startDate.getTime();
}
The usage is then trivial:
var isValid = isValidURL("http://example.com");
alert(isValid ? "Valid URL!!!" : "Damn...");
Or:
var responseInMillis = ping("example.com");
alert(responseInMillis);
const ping = (url, timeout = 6000) => {
return new Promise((resolve, reject) => {
const urlRule = new RegExp('(https?|ftp|file)://[-A-Za-z0-9+&##/%?=~_|!:,.;]+[-A-Za-z0-9+&##/%=~_|]');
if (!urlRule.test(url)) reject('invalid url');
try {
fetch(url)
.then(() => resolve(true))
.catch(() => resolve(false));
setTimeout(() => {
resolve(false);
}, timeout);
} catch (e) {
reject(e);
}
});
};
use like this:
ping('https://stackoverflow.com/')
.then(res=>console.log(res))
.catch(e=>console.log(e))
I don't know what version of Ruby you're running, but have you tried implementing ping for ruby instead of javascript? http://raa.ruby-lang.org/project/net-ping/
let webSite = 'https://google.com/'
https.get(webSite, function (res) {
// If you get here, you have a response.
// If you want, you can check the status code here to verify that it's `200` or some other `2xx`.
console.log(webSite + ' ' + res.statusCode)
}).on('error', function(e) {
// Here, an error occurred. Check `e` for the error.
console.log(e.code)
});;
if you run this with node it would console log 200 as long as google is not down.
You can run the DOS ping.exe command from javaScript using the folowing:
function ping(ip)
{
var input = "";
var WshShell = new ActiveXObject("WScript.Shell");
var oExec = WshShell.Exec("c:/windows/system32/ping.exe " + ip);
while (!oExec.StdOut.AtEndOfStream)
{
input += oExec.StdOut.ReadLine() + "<br />";
}
return input;
}
Is this what was asked for, or am i missing something?
just replace
file_get_contents
with
$ip = $_SERVER['xxx.xxx.xxx.xxx'];
exec("ping -n 4 $ip 2>&1", $output, $retval);
if ($retval != 0) {
echo "no!";
}
else{
echo "yes!";
}
It might be a lot easier than all that. If you want your page to load then check on the availability or content of some foreign page to trigger other web page activity, you could do it using only javascript and php like this.
yourpage.php
<?php
if (isset($_GET['urlget'])){
if ($_GET['urlget']!=''){
$foreignpage= file_get_contents('http://www.foreignpage.html');
// you could also use curl for more fancy internet queries or if http wrappers aren't active in your php.ini
// parse $foreignpage for data that indicates your page should proceed
echo $foreignpage; // or a portion of it as you parsed
exit(); // this is very important otherwise you'll get the contents of your own page returned back to you on each call
}
}
?>
<html>
mypage html content
...
<script>
var stopmelater= setInterval("getforeignurl('?urlget=doesntmatter')", 2000);
function getforeignurl(url){
var handle= browserspec();
handle.open('GET', url, false);
handle.send();
var returnedPageContents= handle.responseText;
// parse page contents for what your looking and trigger javascript events accordingly.
// use handle.open('GET', url, true) to allow javascript to continue executing. must provide a callback function to accept the page contents with handle.onreadystatechange()
}
function browserspec(){
if (window.XMLHttpRequest){
return new XMLHttpRequest();
}else{
return new ActiveXObject("Microsoft.XMLHTTP");
}
}
</script>
That should do it.
The triggered javascript should include clearInterval(stopmelater)
Let me know if that works for you
Jerry
You could try using PHP in your web page...something like this:
<html><body>
<form method="post" name="pingform" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<h1>Host to ping:</h1>
<input type="text" name="tgt_host" value='<?php echo $_POST['tgt_host']; ?>'><br>
<input type="submit" name="submit" value="Submit" >
</form></body>
</html>
<?php
$tgt_host = $_POST['tgt_host'];
$output = shell_exec('ping -c 10 '. $tgt_host.');
echo "<html><body style=\"background-color:#0080c0\">
<script type=\"text/javascript\" language=\"javascript\">alert(\"Ping Results: " . $output . ".\");</script>
</body></html>";
?>
This is not tested so it may have typos etc...but I am confident it would work. Could be improved too...