How to know that WINDOW.LOCATION load url - javascript

I need to check if iPhone Safari support specific url (lppn://playnow - that url will run Texas Poker application if its already installed) if url does not supported i want to run other link (application page in AppStore).
Are WINDOW.LOCATION return false if it can not load uri?

window.location won't return false, however you can use AJAX for this.
If jQuery is relevant, it's matter of one or two lines of code (AJAX call to the page, handle the onerror event) otherwise you'll have to build it yourself, but it's still possible.

Related

How can I cancel consecutive requests to my server? [duplicate]

What would cause a page to be canceled? I have a screenshot of the Chrome Developer Tools.
This happens often but not every time. It seems like once some other resources are cached, a page refresh will load the LeftPane.aspx. And what's really odd is this only happens in Google Chrome, not Internet Explorer 8. Any ideas why Chrome would cancel a request?
We fought a similar problem where Chrome was canceling requests to load things within frames or iframes, but only intermittently and it seemed dependent on the computer and/or the speed of the internet connection.
This information is a few months out of date, but I built Chromium from scratch, dug through the source to find all the places where requests could get cancelled, and slapped breakpoints on all of them to debug. From memory, the only places where Chrome will cancel a request:
The DOM element that caused the request to be made got deleted (i.e. an IMG is being loaded, but before the load happened, you deleted the IMG node)
You did something that made loading the data unnecessary. (i.e. you started loading a iframe, then changed the src or overwrite the contents)
There are lots of requests going to the same server, and a network problem on earlier requests showed that subsequent requests weren't going to work (DNS lookup error, earlier (same) request resulted e.g. HTTP 400 error code, etc)
In our case we finally traced it down to one frame trying to append HTML to another frame, that sometimes happened before the destination frame even loaded. Once you touch the contents of an iframe, it can no longer load the resource into it (how would it know where to put it?) so it cancels the request.
status=canceled may happen also on ajax requests on JavaScript events:
<script>
$("#call_ajax").on("click", function(event){
$.ajax({
...
});
});
</script>
<button id="call_ajax">call</button>
The event successfully sends the request, but is is canceled then (but processed by the server). The reason is, the elements submit forms on click events, no matter if you make any ajax requests on the same click event.
To prevent request from being cancelled, JavaScript event.preventDefault(); have to be called:
<script>
$("#call_ajax").on("click", function(event){
event.preventDefault();
$.ajax({
...
});
});
</script>
NB: Make sure you don't have any wrapping form elements.
I had a similar issue where my button with onclick={} was wrapped in a form element. When clicking the button the form is also submitted, and that messed it all up...
Another thing to look out for could be the AdBlock extension, or extensions in general.
But "a lot" of people have AdBlock....
To rule out extension(s) open a new tab in incognito making sure that "allow in incognito is off" for the extention(s) you want to test.
In my case, I found that it is jquery global timeout settings, a jquery plugin setup global timeout to 500ms, so that when the request exceed 500ms, chrome will cancel the request.
You might want to check the "X-Frame-Options" header tag. If its set to SAMEORIGIN or DENY then the iFrame insertion will be canceled by Chrome (and other browsers) per the spec.
Also, note that some browsers support the ALLOW-FROM setting but Chrome does not.
To resolve this, you will need to remove the "X-Frame-Options" header tag. This could leave you open to clickjacking attacks so you will need to decide what the risks are and how to mitigate them.
Here's what happened to me: the server was returning a malformed "Location" header for a 302 redirect.
Chrome failed to tell me this, of course. I opened the page in firefox, and immediately discovered the problem.
Nice to have multiple tools :)
Another place we've encountered the (canceled) status is in a particular TLS certificate misconfiguration. If a site such as https://www.example.com is misconfigured such that the certificate does not include the www. but is valid for https://example.com, chrome will cancel this request and automatically redirect to the latter site. This is not the case for Firefox.
Currently valid example: https://www.pthree.org/
A cancelled request happened to me when redirecting between secure and non-secure pages on separate domains within an iframe. The redirected request showed in dev tools as a "cancelled" request.
I have a page with an iframe containing a form hosted by my payment gateway. When the form in the iframe was submitted, the payment gateway would redirect back to a URL on my server. The redirect recently stopped working and ended up as a "cancelled" request instead.
It seems that Chrome (I was using Windows 7 Chrome 30.0.1599.101) no longer allowed a redirect within the iframe to go to a non-secure page on a separate domain. To fix it, I just made sure any redirected requests in the iframe were always sent to secure URLs.
When I created a simpler test page with only an iframe, there was a warning in the console (which I had previous missed or maybe didn't show up):
[Blocked] The page at https://mydomain.com/Payment/EnterDetails ran insecure content from http://mydomain.com/Payment/Success
The redirect turned into a cancelled request in Chrome on PC, Mac and Android. I don't know if it is specific to my website setup (SagePay Low Profile) or if something has changed in Chrome.
Chrome Version 33.0.1750.154 m consistently cancels image loads if I am using the Mobile Emulation pointed at my localhost; specifically with User Agent spoofing on (vs. just Screen settings).
When I turn User Agent spoofing off; image requests aren't canceled, I see the images.
I still don't understand why; in the former case, where the request is cancelled the Request Headers (CAUTION: Provisional headers are shown) have only
Accept
Cache-Control
Pragma
Referer
User-Agent
In the latter case, all of those plus others like:
Cookie
Connection
Host
Accept-Encoding
Accept-Language
Shrug
I got this error in Chrome when I redirected via JavaScript:
<script>
window.location.href = "devhost:88/somepage";
</script>
As you see I forgot the 'http://'. After I added it, it worked.
Here is another case of request being canceled by chrome, which I just encountered, which is not covered by any of answers up there.
In a nutshell
Self-signed certificate not being trusted on my android phone.
Details
We are in development/debug phase. The url is pointing to a self-signed host. The code is like:
location.href = 'https://some.host.com/some/path'
Chrome just canceled the request silently, leaving no clue for newbie to web development like myself to fix the issue. Once I downloaded and installed the certificate using the android phone the issue is gone.
If you use axios it can help you
// change timeout delay:
instance.defaults.timeout = 2500;
https://github.com/axios/axios#config-order-of-precedence
For my case, I had an anchor with click event like
<a href="" onclick="somemethod($index, hour, $event)">
Inside click event I had some network call, Chrome cancelling the request. The anchor has href with "" means, it reloads the page and the same time it has click event with network call that gets cancelled. Whenever i replace the href with void like
<a href="javascript:void(0)" onclick="somemethod($index, hour, $event)">
The problem went away!
If you make use of some Observable-based HTTP requests like those built-in in Angular (2+), then the HTTP request can be canceled when observable gets canceled (common thing when you're using RxJS 6 switchMap operator to combine the streams). In most cases it's enough to use mergeMap operator instead, if you want the request to complete.
I had faced the same issue, somewhere deep in our code we had this pseudocode:
create an iframe
onload of iframe submit a form
After 2 seconds, remove the iframe
thus, when the server takes more than 2 seconds to respond the iframe to which the server was writing the response to, was removed, but the response was still to be written , but there was no iframe to write , thus chrome cancelled the request, thus to avoid this I made sure that the iframe is removed only after the response is over, or you can change the target to "_blank".
Thus one of the reason is:
when the resource(iframe in my case) that you are writing something in, is removed or deleted before you stop writing to it, the request will be cancelled
I have embedded all types of font as well as woff, woff2, ttf when I embed a web font in style sheet. Recently I noticed that Chrome cancels request to ttf and woff when woff2 is present. I use Chrome version 66.0.3359.181 right now but I am not sure when Chrome started canceling of extra font types.
We had this problem having tag <button> in the form, that was supposed to send ajax request from js. But this request was canceled, due to browser, that sends form automatically on any click on button inside the form.
So if you realy want to use button instead of regular div or span on the page, and you want to send form throw js - you should setup a listener with preventDefault function.
e.g.
$('button').on('click', function(e){
e.preventDefault();
//do ajax
$.ajax({
...
});
})
I had the exact same thing with two CSS files that were stored in another folder outside my main css folder. I'm using Expression Engine and found that the issue was in the rules in my htaccess file. I just added the folder to one of my conditions and it fixed it. Here's an example:
RewriteCond %{REQUEST_URI} !(images|css|js|new_folder|favicon.ico)
So it might be worth you checking your htaccess file for any potential conflicts
happened to me the same when calling a. js file with $. ajax, and make an ajax request, what I did was call normally.
In my case the code to show e-mail client window caused Chrome to stop loading images:
document.location.href = mailToLink;
moving it to $(window).load(function () {...}) instead of $(function () {...}) helped.
In can this helps anybody I came across the cancelled status when I left out the return false; in the form submit. This caused the ajax send to be immediately followed by the submit action, which overwrote the current page. The code is shown below, with the important return false at the end.
$('form').submit(function() {
$.validator.unobtrusive.parse($('form'));
var data = $('form').serialize();
data.__RequestVerificationToken = $('input[name=__RequestVerificationToken]').val();
if ($('form').valid()) {
$.ajax({
url: this.action,
type: 'POST',
data: data,
success: submitSuccess,
fail: submitFailed
});
}
return false; //needed to stop default form submit action
});
Hope that helps someone.
For anyone coming from LoopbackJS and attempting to use the custom stream method like provided in their chart example. I was getting this error using a PersistedModel, switching to a basic Model fixed my issue of the eventsource status cancelling out.
Again, this is specifically for the loopback api. And since this is a top answer and top on google i figured i'de throw this in the mix of answers.
For me 'canceled' status was because the file did not exist. Strange why chrome does not show 404.
It was as simple as an incorrect path for me. I would suggest the first step in debugging would be to see if you can load the file independently of ajax etc.
The requests might have been blocked by a tracking protection plugin.
It happened to me when loading 300 images as background images. I'm guessing once first one timed out, it cancelled all the rest, or reached max concurrent request. need to implement a 5-at-a-time
One the reasons could be that the XMLHttpRequest.abort() was called somewhere in the code, in this case, the request will have the cancelled status in the Chrome Developer tools Network tab.
In my case, it started coming after chrome 76 update.
Due to some issue in my JS code, window.location was getting updated multiple times which resulted in canceling previous request.
Although the issue was present from before, chrome started cancelling request after update to version 76.
I had the same issue when updating a record. Inside the save() i was prepping the rawdata taken from the form to match the database format (doing a lot of mapping of enums values, etc), and this intermittently cancels the put request. i resolved it by taking out the data prepping from the save() and creating a dedicated dataPrep() method out of it. I turned this dataPrep into async and await all the memory intensive data conversion. I then return the prepped data to the save() method that i could use in the http put client. I made sure i await on dataPrep() before calling the put method:
await dataToUpdate = await dataPrep();
http.put(apiUrl, dataToUpdate);
This solved the intermittent cancelling of request.

How can I get the url of a page that didn't load with javascript?

I am trying to code an add-on for Firefox that redirects you to another website if the URL includes any given string. This works for pages that load correctly, but say if a page didnt load(could be blocked etc.) my code doesn't get the URL.
I tried window.location.href but this does not work on unloaded pages.
For pages that load, window.location.href works.
I expect to get the URL even on pages that failed to load.
Long story short, I want to know how can I get the URL of this page with javascript?
http://www.randomrandomrandomrandom.com/
I think you might want to look into the tabs.getCurrent function from the Mozilla docs. As you said, window.location.href only works once the page is loaded, so what you want to do is check for the URL before the page is even loaded since you are not sure whether it will load or not.
function getURL(tabInfo) {
console.log(tabInfo.url);
}
function logError(error) {
console.log(`Error: ${error}`);
}
var gettingCurrent = browser.tabs.getCurrent();
gettingCurrent.then(getURL, logError);
The URL option is only present if the extension has the "tabs" permission. (Source)

Force (or ask nicely) to refresh the browser

So I run a site that uses a lot of javascript and ajax. I understand how to make users refresh their browser when the browser loads. But what happens if I need them to refresh their browser after they have loaded the site?
I want to change the ajax that is served to the client to speed up things up, but this is going to cause errors for the users who have not yet refreshed their browser.
The only solution I can come up with is that when a new version of the JavaScript file is required, the site uses a popup that asks the users to force refresh their browsers. (This won't really fix the current version, but would prevent future issues.)
I hate to use a popup for something that I could do automatically. Is there a better way to force updates for the client?
window.location.href = "http://example.com"
replaces the current page with the one pointed to by http://example.com.
You sound like you are having trouble with your JavaScript getting an updated version of the data it loads through Ajax methods, is that correct? For instance, if two Ajax calls try to load 'data.txt', then the second call merely uses the cached version.
You also may be having trouble with loading new versions your script itself.
The way around both of these problems is to add a randomly-generated query string to your script source and your Ajax source.
For example, make one script that loads your main script, like this:
/* loader1.js */
document.write('<script src="mainjavascript.js?.rand=', Math.random(), '"></script>');
And in your HTML, just do
<script src="loader1.js"></script>
The same method works for JavaScript Ajax requests as well. Assuming that "client" is a new XMLHttpRequest() object, and has been properly set up with a readystatechange function and so on, then the you simply append the same query string, like this:
request = client.open('GET', 'data.txt?.rand=' + Math.random(), true);
request.send();
You may be using a library to do your Ajax requests, and so it's even easier then. Just specify the data URL as 'data.txt?.rand=' + Math.random() instead of merely 'data.txt'

Authenticate a facebook user in a Firefox plug-in

I'm trying to write a Firefox plug-in that accesses data from facebook.
Now I'm not sure how to get an access token.
I tried to implement the client side flow for desktop apps (with the fixed redirect uri), but the big problem I encounter there, is that JavaScript doesn't allow me to wait for the redirect to happen.
Any idea how this could be done?
As far as I understood it, because I don't have a webpage, the JavaScript API doesn't help much, right?
I guess that you are opening https://www.facebook.com/dialog/oauth in a browser tab to let the user log in and give you access. You don't need to pass a working redirect URL here, you can rather use something that will definitely not work, like http://my.extension.local/. Then you only need to detect when the tab gets redirected to that URL. If you have a classic extension, you register a progress listener on the <browser> element of that tab and look at onLocationChange() calls - once you see a location starting with http://my.extension.local/ you can cancel the request and close the tab, the necessary data is in the URL. If you use the Add-on SDK you can attach a ready event listener to the tab, something along these lines:
var tabs = require("tabs");
tabs.open({
url: "https://www.facebook.com/dialog/oauth?...",
inBackground: false,
onReady: function(tab)
{
if (tab.url.indexOf("http://my.extension.local/") == 0)
{
...
}
}
});

load page and execute javascript in a url

Hello wonderful stackoverflow users.
I have a question about url loading.
In many browsers and web viewers, there is the functionality to load a url to a website, but also a url to execute javascript.
Load a website: http://www.google.com
Load a script: javascript:alert("Hello!");
My question is, is there a way to load an http request as well as a javascript.
The answer is most likely no, but I want to confirm because I can't find any resources that describe this.
I was thinking it would be something like:
http://www.google.com&&javascript:alert("Hello!");
but the problem is, of course, this is not correct.
The reason why I am doing this is to provide a url that once it is clicked, it will also execute a certain javascript function. This will be in Android.
I appreciate any response, and understand that the answer may be no.
It all depends on whether you have control of the page being linked to. If you cannot modify the source of the linked page, then the answer is quite simply, no.
But, if it is your page, you can pass arguments in the hash, and then read the hash when the page loads and execute script accordingly.
window.onload = function () {
if (location.hash.indexOf("doSomething") > -1) {
// do something
}
};
You can execute javascript when a page loads using Browser plugins, such as GreaseMonkey for Firefox, or TamperMonkey for Chrome.
https://addons.mozilla.org/en-us/firefox/addon/greasemonkey/
http://tampermonkey.net/index.php?version=3.11&ext=dhdg&updated=true

Categories

Resources