how to get jquery to run repeatedly - javascript

I currently have a piece of jquery code that looks for a specific URL (with an anchor at the end) and runs a function if it has a match. The code only runs once, if this is the first URL loaded. Is it possible to have the following code running until it has a match?
$(document).ready(function(){
var url = "https://s3-eu-west-1.amazonaws.com/datahealthcheck16-test/index.html#backup-section-3";
$(function(){
if (location.href==url){
paintLine();
}
})
});

It only runs the first time, because changing the hash does not fire the DOM ready handler again, it does however fire the hashchange event.
$(window).on('hashchange', function() {
if ( window.location.hash === '#backup-section-3' ) {
paintLine();
}
}).trigger('hashchange'); // fire on first load as well
Note that the window is always available, and does not need a DOM ready handler

you can use setTimeout() function to run your function, for example every second:
$(document).ready(function(){
var url = "https://s3-eu-west-1.amazonaws.com/datahealthcheck16-test/index.html#backup-section-3";
function test() {
if (location.href == url) {
paintLine();
} else {
setTimeout(test, 1000);
}
}
test();
});
but what is your idea, behind your code? I sure there is more convenient ways to do your task.

using adeneo's answer:
here is what matches your code:
$(document).ready(function(){
var url = "https://s3-eu-west-1.amazonaws.com/datahealthcheck16-test/index.html#backup-section-3";
$(function(){
if (location.href==url){
paintLine();
}
});
$(window).on('hashchange', function() {
if ( location.href == url ) {
paintLine();
}
});
});

Related

Detect Close window event function [duplicate]

I want to capture the browser window/tab close event.
I have tried the following with jQuery:
jQuery(window).bind(
"beforeunload",
function() {
return confirm("Do you really want to close?")
}
)
But it works on form submission as well, which is not what I want. I want an event that triggers only when the user closes the window.
The beforeunload event fires whenever the user leaves your page for any reason.
For example, it will be fired if the user submits a form, clicks a link, closes the window (or tab), or goes to a new page using the address bar, search box, or a bookmark.
You could exclude form submissions and hyperlinks (except from other frames) with the following code:
var inFormOrLink;
$('a').on('click', function() { inFormOrLink = true; });
$('form').on('submit', function() { inFormOrLink = true; });
$(window).on("beforeunload", function() {
return inFormOrLink ? "Do you really want to close?" : null;
})
For jQuery versions older than 1.7, try this:
var inFormOrLink;
$('a').live('click', function() { inFormOrLink = true; });
$('form').bind('submit', function() { inFormOrLink = true; });
$(window).bind("beforeunload", function() {
return inFormOrLink ? "Do you really want to close?" : null;
})
The live method doesn't work with the submit event, so if you add a new form, you'll need to bind the handler to it as well.
Note that if a different event handler cancels the submit or navigation, you will lose the confirmation prompt if the window is actually closed later. You could fix that by recording the time in the submit and click events, and checking if the beforeunload happens more than a couple of seconds later.
Maybe just unbind the beforeunload event handler within the form's submit event handler:
jQuery('form').submit(function() {
jQuery(window).unbind("beforeunload");
...
});
For a cross-browser solution (tested in Chrome 21, IE9, FF15), consider using the following code, which is a slightly tweaked version of Slaks' code:
var inFormOrLink;
$('a').live('click', function() { inFormOrLink = true; });
$('form').bind('submit', function() { inFormOrLink = true; });
$(window).bind('beforeunload', function(eventObject) {
var returnValue = undefined;
if (! inFormOrLink) {
returnValue = "Do you really want to close?";
}
eventObject.returnValue = returnValue;
return returnValue;
});
Note that since Firefox 4, the message "Do you really want to close?" is not displayed. FF just displays a generic message. See note in https://developer.mozilla.org/en-US/docs/DOM/window.onbeforeunload
window.onbeforeunload = function () {
return "Do you really want to close?";
};
My answer is aimed at providing simple benchmarks.
HOW TO
See #SLaks answer.
$(window).on("beforeunload", function() {
return inFormOrLink ? "Do you really want to close?" : null;
})
How long does the browser take to finally shut your page down?
Whenever an user closes the page (x button or CTRL + W), the browser executes the given beforeunload code, but not indefinitely. The only exception is the confirmation box (return 'Do you really want to close?) which will wait until for the user's response.
Chrome: 2 seconds.
Firefox: ∞ (or double click, or force on close)
Edge: ∞ (or double click)
Explorer 11: 0 seconds.
Safari: TODO
What we used to test this out:
A Node.js Express server with requests log
The following short HTML file
What it does is to send as many requests as it can before the browser shut downs its page (synchronously).
<html>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script>
function request() {
return $.ajax({
type: "GET",
url: "http://localhost:3030/" + Date.now(),
async: true
}).responseText;
}
window.onbeforeunload = () => {
while (true) {
request();
}
return null;
}
</script>
</body>
</html>
Chrome output:
GET /1480451321041 404 0.389 ms - 32
GET /1480451321052 404 0.219 ms - 32
...
GET /hello/1480451322998 404 0.328 ms - 32
1957ms ≈ 2 seconds // we assume it's 2 seconds since requests can take few milliseconds to be sent.
For a solution that worked well with third party controls like Telerik (ex.: RadComboBox) and DevExpress that use the Anchor tags for various reasons, consider using the following code, which is a slightly tweaked version of desm's code with a better selector for self targeting anchor tags:
var inFormOrLink;
$('a[href]:not([target]), a[href][target=_self]').live('click', function() { inFormOrLink = true; });
$('form').bind('submit', function() { inFormOrLink = true; });
$(window).bind('beforeunload', function(eventObject) {
var returnValue = undefined;
if (! inFormOrLink) {
returnValue = "Do you really want to close?";
}
eventObject.returnValue = returnValue;
return returnValue;
});
I used Slaks answer but that wasn't working as is, since the onbeforeunload returnValue is parsed as a string and then displayed in the confirmations box of the browser. So the value true was displayed, like "true".
Just using return worked.
Here is my code
var preventUnloadPrompt;
var messageBeforeUnload = "my message here - Are you sure you want to leave this page?";
//var redirectAfterPrompt = "http://www.google.co.in";
$('a').live('click', function() { preventUnloadPrompt = true; });
$('form').live('submit', function() { preventUnloadPrompt = true; });
$(window).bind("beforeunload", function(e) {
var rval;
if(preventUnloadPrompt) {
return;
} else {
//location.replace(redirectAfterPrompt);
return messageBeforeUnload;
}
return rval;
})
Perhaps you could handle OnSubmit and set a flag that you later check in your OnBeforeUnload handler.
Unfortunately, whether it is a reload, new page redirect, or browser close the event will be triggered. An alternative is catch the id triggering the event and if it is form dont trigger any function and if it is not the id of the form then do what you want to do when the page closes. I am not sure if that is also possible directly and is tedious.
You can do some small things before the customer closes the tab. javascript detect browser close tab/close browser but if your list of actions are big and the tab closes before it is finished you are helpless. You can try it but with my experience donot depend on it.
window.addEventListener("beforeunload", function (e) {
var confirmationMessage = "\o/";
/* Do you small action code here */
(e || window.event).returnValue = confirmationMessage; //Gecko + IE
return confirmationMessage; //Webkit, Safari, Chrome
});
https://developer.mozilla.org/en-US/docs/Web/Reference/Events/beforeunload?redirectlocale=en-US&redirectslug=DOM/Mozilla_event_reference/beforeunload
jQuery(window).bind("beforeunload", function (e) {
var activeElementTagName = e.target.activeElement.tagName;
if (activeElementTagName != "A" && activeElementTagName != "INPUT") {
return "Do you really want to close?";
}
})
If your form submission takes them to another page (as I assume it does, hence the triggering of beforeunload), you could try to change your form submission to an ajax call. This way, they won't leave your page when they submit the form and you can use your beforeunload binding code as you wish.
As of jQuery 1.7, the .live() method is deprecated. Use .on() to attach event handlers. Users of older versions of jQuery should use .delegate() in preference to .live()
$(window).bind("beforeunload", function() {
return true || confirm("Do you really want to close?");
});
on complete or link
$(window).unbind();
Try this also
window.onbeforeunload = function ()
{
if (pasteEditorChange) {
var btn = confirm('Do You Want to Save the Changess?');
if(btn === true ){
SavetoEdit();//your function call
}
else{
windowClose();//your function call
}
} else {
windowClose();//your function call
}
};
My Issue: The 'onbeforeunload' event would only be triggered if there were odd number of submits(clicks). I had a combination of solutions from similar threads in SO to have my solution work. well my code will speak.
<!--The definition of event and initializing the trigger flag--->
$(document).ready(function() {
updatefgallowPrompt(true);
window.onbeforeunload = WarnUser;
}
function WarnUser() {
var allowPrompt = getfgallowPrompt();
if(allowPrompt) {
saveIndexedDataAlert();
return null;
} else {
updatefgallowPrompt(true);
event.stopPropagation
}
}
<!--The method responsible for deciding weather the unload event is triggered from submit or not--->
function saveIndexedDataAlert() {
var allowPrompt = getfgallowPrompt();
var lenIndexedDocs = parseInt($('#sortable3 > li').size()) + parseInt($('#sortable3 > ul').size());
if(allowPrompt && $.trim(lenIndexedDocs) > 0) {
event.returnValue = "Your message";
} else {
event.returnValue = " ";
updatefgallowPrompt(true);
}
}
<!---Function responsible to reset the trigger flag---->
$(document).click(function(event) {
$('a').live('click', function() { updatefgallowPrompt(false); });
});
<!--getter and setter for the flag---->
function updatefgallowPrompt (allowPrompt){ //exit msg dfds
$('body').data('allowPrompt', allowPrompt);
}
function getfgallowPrompt(){
return $('body').data('allowPrompt');
}
Just verify...
function wopen_close(){
var w = window.open($url, '_blank', 'width=600, height=400, scrollbars=no, status=no, resizable=no, screenx=0, screeny=0');
w.onunload = function(){
if (window.closed) {
alert("window closed");
}else{
alert("just refreshed");
}
}
}
var validNavigation = false;
jQuery(document).ready(function () {
wireUpEvents();
});
function endSession() {
// Browser or broswer tab is closed
// Do sth here ...
alert("bye");
}
function wireUpEvents() {
/*
* For a list of events that triggers onbeforeunload on IE
* check http://msdn.microsoft.com/en-us/library/ms536907(VS.85).aspx
*/
window.onbeforeunload = function () {
debugger
if (!validNavigation) {
endSession();
}
}
// Attach the event keypress to exclude the F5 refresh
$(document).bind('keypress', function (e) {
debugger
if (e.keyCode == 116) {
validNavigation = true;
}
});
// Attach the event click for all links in the page
$("a").bind("click", function () {
debugger
validNavigation = true;
});
// Attach the event submit for all forms in the page
$("form").bind("submit", function () {
debugger
validNavigation = true;
});
// Attach the event click for all inputs in the page
$("input[type=submit]").bind("click", function () {
debugger
validNavigation = true;
});
}`enter code here`
Following worked for me;
$(window).unload(function(event) {
if(event.clientY < 0) {
//do whatever you want when closing the window..
}
});

Detect if script has already loaded or not

It seems that helloworld.js gets loaded multiple times based on the number of times I click #load. I say this because when I look at Google Chromes Developer Tools Network tab, it shows helloworld.js as many times as I click #load.
$(document).ready(function() {
$("#load").click(function(){
$.getScript('helloworld.js', function() {
hello();
});
});
});
The hello() function looks like this:
function hello(){
alert("hello");
}
Is it possible to detect if helloworld.js has already loaded?
So if it hasn't loaded, load it, and if it has loaded, don't load it.
This is what Developer Tools currently shows me if I click the #load button 4 times:
Set a flag when file loaded successfully. If flag is set then skip the file loading again.
Try this code,
var isLoaded = 0; //Set the flag OFF
$(document).ready(function() {
$("#load").click(function(){
if(isLoaded){ //If flag is ON then return false
alert("File already loaded");
return false;
}
$.getScript('helloworld.js', function() {
isLoaded = 1; //Turn ON the flag
hello();
});
});
});
So why not only fire the event once like this:
$("#load").one("click", function() {
$load = $(this);
$.getScript('helloworld.js', function() {
hello();
// bind hello to the click event of load for subsequent calls
$load.on('click', hello);
});
});
That would prevent subsequent loads and avoids the use of a global
Another option is letting .getScript() run but let it take the script from browser's cache so you won't have it reloaded each and every time.
To achieve this, add such code:
$.ajaxSetup({
cache: true
});
This is taken from the documentation page.
You could create a helper function:
var getScript = (function() {
var loadedFiles = {};
return function(filename, callback) {
if(loadedFiles[filename]) {
callback();
} else {
$.getScript(filename, function() {
loadedFiles[filename] = true;
callback();
});
}
};
})();

how do i fire an event when document readyState is complete

I want to fire and event when the DOM has completely loaded. I checked out document.readyState but it's not an event. I want to fire it when the readyState is complete. How do I do that?
Some easy googling point me to this code:
// alternative to DOMContentLoaded
document.onreadystatechange = function () {
if (document.readyState == "complete") {
initApplication();
}
}
And to this link
Handle the window.load event.
This will only fire when all external resources (including images) have loaded.
Taken from another post, however, you could do it like this:
var alreadyrunflag = 0; //flag to indicate whether target function has already been run
if (document.addEventListener) {
document.addEventListener("DOMContentLoaded", function() {
alreadyrunflag = 1;
// perform what you need to
}, false);
} else if (document.all && !window.opera) {
var contentloadtag = document.getElementById("contentloadtag");
contentloadtag.onreadystatechange = function() {
if (this.readyState == "complete") {
alreadyrunflag = 1;
// perform what you need to
}
}
}
//fallback
window.onload = function() {
setTimeout(function() {
if (!alreadyrunflag) {
// perform what you need to
}
}, 0);
}
This checks that the DOM is fully loaded, however, if it isn't, it falls back to onload. You can obviously manipulate this though.
Also, if JQuery is an option, you can achieve the same effect by using just one simple function:
$(document).ready(function() {
// Handler for .ready() called.
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js"></script>
You can do it like this:
function startupApplication(anyFunction) {
document.onreadystatechange = function () {
document.onreadystatechange = () =>
document.readyState === "complete" ? anyFunction() : undefined;
};
}
startupApplication(() => {
// Put your code here ...
});
See my FiddleJS with comments and logs for education purposes: click here
For anyone already using the jQuery library the ready function can be used to handle this.
Otherwise the solution from #Neal will achieve the same functionality without needing to add an additional dependency.

popstate HTML 5 event being fired multiple times

Hi i am using the following code to load a part of page dynamically using jquery
loadNextBackInPage_URL = null;
function callBackFunctionLoadNextBackInPage(data)
{
//alert(data);
$("#left").fadeTo(100,1);
var data = $(data).find( '#left' );
$("#left").html(data);
if(supports_history_api())
{
history.pushState(null, null, loadNextBackInPage_URL);
window.addEventListener("popstate", function(e) {
alert('s');
loadNextBackInPage(location.pathname);
});
}
else
{
}
}
function loadNextBackInPage(url,parm)
{
//alert(url);
loadNextBackInPage_URL = url;
$("#left").fadeTo(100,.2);
$.post(url,parm,callBackFunctionLoadNextBackInPage,'html');
}
The loading part and even changing the browser URL is working. but why is the PoP state function being fired multiple times?
I call loadNextBackInPage() originally through an onclick function.
I got it solved from here in codingforums
think you keep adding "popstate"
listeners over and over ...
Program logic:
Page loaded
onclick will execute loadNextBackInPage()
Start a $.post() Request and fire "callBackFunctionLoadNextBackInPage" on completion
pushState()
Register an event listener for "popstate"
When "popstate" fires, execute loadNextBackInPage() and return to step 2
So step 4 will be executed over and
over which will register new event
listeners. Every time "popstate" fires
all the event listeners will execute
Try to move the addEventListener
method call out of this loop
So from those i derived a workaround and also corrected location.pathname to location.href
The corrected code:
loadNextBackInPage_URL = null;
popEventListnerAdded = false;
function callBackFunctionLoadNextBackInPage(data)
{
//alert(data);
$("#left").fadeTo(100,1);
var data = $(data).find( '#left' );
$("#left").html(data);
if(supports_history_api())
{
history.pushState(null, null, loadNextBackInPage_URL);
if(!popEventListnerAdded) {
window.addEventListener("popstate", function(e) {
loadNextBackInPage(location.href);
});
popEventListnerAdded = true;
}
}
else
{
}
}
function loadNextBackInPage(url,parm)
{
//alert(url);
loadNextBackInPage_URL = url;
$("#left").fadeTo(100,.2);
$.post(url,parm,callBackFunctionLoadNextBackInPage,'html');
}

How to use jQuery click event to change href value asynchronously, based on a JSON query

I'm using the bit.ly url shortening service to shorten certain url's being sent to a "share on twitter" function. I'd like to load the bit.ly url only when a user actually presses the share button (due to bit.ly's max 5 parallel reqs limitation). Bit.ly's REST API returns a JSON callback with the shortened url, which makes the whole scenario async.
I've tried the following to stop the click event, and wait for the JSON call to return a value before launching the click.
I have the following simplified code in jQuery(document).ready():
Updated code (oversimplified)!
jQuery("#idofaelement").click(function(event) {
event.preventDefault(); //stop the click action
var link = jQuery(this);
bitlyJSON(function(shortUrl) {
link.attr("href", function() {
//process shortUrl
//return finalized url;
}).unbind().click();
});
});
And the following code to handle the bitly shortening (works just fine):
function bitlyJSON(func) {
//
// build apiUrl here
//
jQuery.getJSON(apiUrl, function(data) {
jQuery.each(data, function(i, entry) {
if (i == "errorCode") {
if (entry != "0") {
func(longUrl);}
} else if (i == "results") {
func(entry[longUrl].shortUrl);}
});
});
} (jQuery)
The href gets its value changed, but the final .click() event never gets fired. This works fine when defining a static value for the href, but not when using the async JSON method.
As you outlined yourself:
event.preventDefault(); //stop the click action
That means, BROWSER IS NOT GOING TO THAT URL, if you wish to actually go forward to the long-url location, simply do something like:
document.location.href = longurl;
iirc, jquery doesn't trigger "click" on A elements. I'd try old good "location.href=whatever" in the callback.
bitlyJSON(function(shortUrl) {
link.attr("href", function() {
//process shortUrl
//return finalized url;
});
location.href = link.attr("href");
});
I think what you actually want is to return false; from the click event, to prevent the actual following of the href, right?
Like:
jQuery("#idofaelement").click(function(event) {
//event.preventDefault(); //stop the click action
var link = jQuery(this);
bitlyJSON(function(shortUrl) {
link.attr("href", function() {
//process shortUrl
//return finalized url;
}).unbind().click();
});
return false;
});
#Tzury Bar Yochay pointed me in the right direction by suggesting I use location.href to update the url. Also #Victor helped with his answer.
I got things kinda working combining the answers, but had issues with the history in firefox. Seems that updating window.location indeed redirected the user, but also removed the "source page" from the history. This did not happen in chrome, safari, ie8, ie8-compatibility or ie7.
Based on this response to another question I was able to create a workaround giving the following working code + made a few changes:
jQuery("#idofaelement").one("click", function(event) {
bitlyJSON(function(shortUrl) {
jQuery("#idofaelement").attr("href", function() {
//process shortUrl
//return finalized url;
});
setTimeout(function() {
window.location = jQuery("#idofaelement").attr("href");
}, 0);
});
return false;
});
Thanks for all the help!

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