Here is the situation. A popup window contains the javascript I need to debug. It also contains a re-direct that happens so fast I can't open the Inspector fast enough to have the breakpoints fire. I start with the Inspector open and click a link which closes the Inspector and opens the popup window which contains the javascript. But the logic happens and the re-direct fires so fast I can't open the Inspector before Chrome is already off the popup with the script I need to debug.
I've read the Google documentation and setting breakpoints works great but the breakpoints only fire if the Inspector is open.
I tried using debugger; which I found from this SA answer but once again, it only fires if the Inspector is open.
Just to debug it, I also tried setting a "sleep" function (which chews up processor, is bad etc) like this:
function sleep(milliSeconds){
var startTime = new Date().getTime(); // get the current time
while (new Date().getTime() < startTime + milliSeconds); // hog cpu
}
sleep(5000);
That didn't work either.
Is there a way to get the Inspector to pop open via code? If not, what is the best way to debug this?
Thanks.
I've been struggling with this issue all day and finally hit upon a solution. Simply place an alert in your code before the debugger statenent:
alert('Time to attach the debugger');
debugger;
When the alert appears on the screen, simply click the "inspect" link in Chrome Inspector. The inspector will attach to your page and you can then click OK on the alert box to continue. It will then stop at the debugger statement
Related
I'm brand new to StackOverflow and userscripts, and I'm trying to get a fresh start!
Worthless information aside, I'm having a bit of trouble with a tiny script I recently whipped up.
(function () {
$("#enbut").click();
setTimeout(function () {
open(location, '_self');
window.close();
}, 100);
})();
What it does is clicks a button, waits a second for the website to register that I've clicked it, and then it closes the webpage.
The only issue that I am having is that it does not seem to want to close the webpage when the tab isn't the one I currently have active (Opened up so I can see it).
The script works fine if I open the webpage directly, but if I right click and open in a new tab, it's able to click the button, but the page doesn't close until I open up the tab.
Is there any reason this would be happening, or any way to fix it?
I'm using Chrome, so maybe it's just a browser security feature like what they have done with closing windows?
window.close(); throws a security issue when used as a general userscript in today's browsers. Even when using the work around ( open(location, '_self'); ), it does not seem to allow it in tabs that are not the active window.
In order to resolve this, I had to convert the userscript to a Chrome Extension, which gives the script full control over Chrome's security measures. I don't think there would be any other way to get this working as a plain userscript without messing with Chrome's internals, which would be a stupid thing to do for a simple script.
Thanks for the help, guys!
I am facing a wired scenario in Firefox 4. When I close the tab window.onbeforeunload is getting called. But when user is closing the window by the cross bar it is not getting called.
Is that a bug in Firefox or there is some other thing I need to do . Please check my code.
$(document).ready(function(){
window.onbeforeunload = function(){signout()};
});
window.onbeforeunload = function(){signout()};
Even writing this code outside document.ready is also not working. The same code is working on chrome.
The scenario get's even wired when their are more than one tabs are opened and then user closes the window (not the tab) by cross bar. In this scenario , Firefox asks the user to confirm that he is closing two tabs and after that my code works !!!. This is quite surprising my code does not work only when my page is the only tab and the user closes the window.
There's a thread on it here:
window.onunload only fires when a tab is closed in firefox, not the entire browser
It looks like it was a feature around that time to prevent unscrupulous websites from preventing browser being fully closed. I wouldn't be surprised if this is still the case, but the only way to find out is to try on a more current version of Firefox.
I'm using chrome's debugger and I'm good when it comes to setting break points once a page is running. My problem is when I do either f5 or press enter on the URL line my break points disappear. How can I set a break point in code that happens when the page first loads?
In Chrome's Developer Tools, go to the Sources tab. On the right, open up Event Listener Breakpoints, and you can set breakpoints on events.
It sounds as if you'll want to set your breakpoint on DOMContentLoaded, which is under the DOM Mutation section.
After you do this, reload the page and you'll end up in the debugger.
Try putting debugger; in your code. That also works in FF's Firebug
Later versions of Safari and Firefox should work properly with breakpoints across reloads, but one needs to be sure that the query is exactly the same between requests. ExtJS 4, for instance, adds a _dc=<epoch> that will disable the cache.
To stop that behavior, add the following:
Ext.Loader.setConfig({
disableCaching: false,
enabled: true
});
Hope that helps!
Chrome JavaScript debugger
I use the next approach that is suitable for Chrome, Safari using Charles Proxy[About] and Rewrite Tool
debugger;
or if you need to make a browser console wait
setTimeout(function(){
debugger;
console.log('gets printed only once after timeout');
}, 7000);
setTimeout is a function that will trigger after delay to give a user time to attach the console
Debugger can be set also by using XHR/fetch breakpoint
In chrome developer tools -> sources tab, in the right pane you can see XHR/fetch breakpoint using that you can set breakpoint.
Add breakpoint
Enter the string which you want to break on. DevTools pauses when this string is present anywhere in an XHR's request URL.
If breakpoint has to be set for all XHR or fetch, please check the option Any XHR or fetch
In firefox developer, tools -> debugger tab, adding to the above feature we can set debugger based on request methods.
If you would like to stop the javascript at the time it's first loaded in the browser (and not when the DOMContentLoaded event listener is triggered which happen later) simply click on pause button in chrome debugger and reload your page with F5 keyboard button.
It worked for me.
I am debugging someone else's web page. There is a link on it which tries to open itself in a popup window, the reason for this is unclear -- there is nothing obvious in the HTML (onclick=foo) to cause this.
Disabling JavaScript means the link opens normally. I have Firefox/Firebug/Dom Inspector and would like to trap whatever JavaScript event is leading to the popup. Since I can't find the code, I'm stuck.
Can Firebug create a sort of global breakpoint to trap all code? Is there some other way to hook into this behaviour and inspect it?
The page in question is http://hijinxmusic.co.uk/ and the problem link is "Green Policy" near the bottom.
Thanks for your time.
The green policy document opens a popup with itself on load:
<body onload="MM_openBrWindow('green%20policy.htm','green','width=900,height=600')">
This is inside green policy.htm
Just to add to David's answer, the function that gets executed on body load in the page at http://hijinxmusic.co.uk/green%20policy.htm essentially calls window.open()
function MM_openBrWindow(theURL,winName,features) { //v2.0
window.open(theURL,winName,features);
}
The bigger problem is that the page that you are trying to open in a new window is the same window that the user is already looking at, which doesn't make any sense. What's more is that if the popup blocker wasn't blocking window creation, you would have an infinite loop of popups (load green policy.html, open a new green policy.html, load green policy.html, etc). Where did you want the popup to happen?
Also, to add to Russ Cam's answer, you can detect when the popup fails to open by checking the return value of window.open. I have used this successfully in Firefox, IE, Opera and Safari (haven't needed to test in Chrome). Using the provided function, this is how I handle blocked popups:
function MM_openBrWindow(theURL,winName,features) { //v2.0
if ( !window.open(theURL, winName, features) ) {
// Window failed to open:
// show a HTML dialog/popover that prompts the user to allow
// popups from this site, along with a `cancel` and `try again`
// button. The `try again` button will attempt to open the
// window again with the provided parameters
dialog.popupBlockedNotice.open(arguments);
}
// Window opened successfully.
}
I have the following JavaScript code to pop up a window in Internet Explorer. The code is executed from a page within a Microsoft CRM modal dialog box. (RequestID is a string that is always the same in the test system - at the moment it contains "abcdefg" - without the quotes).
var cancelUrl = "CancelRequest.aspx?RequestID=" + RequestID;
alert("About to open a window.\n\n" + cancelUrl);
window.open(cancelUrl);
alert("Window opened");
I expect to see a message telling me that I am about to open a window. I then expect to see a window open and get another message about the window having been opened. I don't really care about the order of the last two events; the alerts are there so I know the code has been executed.
I have two PCs and a virtual PC. All running IE7. On the Windows 2003 VPC, the messages and pop-up appear every time without fail.
On the Vista PC and WinXP PC, the messages appear but the pop-up only appears intermittently. (I think this may be the case on the Vista PC too).
All three have identical settings in IE. All have the IE pop-up blocker disabled and have no other pop-up blockers installed.
Can anyone shed any light on this?
Ah, I think I got it... missed it in the description...
You are trying to open a non-modal window from a modal dialog in IE.
This AFAIK, should not work.
Try opening another modal window instead.
Effectively you are saying...
on window A, open up modal window B, now open up non-modal window C, which isn't really valid.
This code is simple. Use debugger and see what is going on.
Check that site with FireFox or Chrome, they have JS debuggers.
Edit:
Add try/catch block around window.open() and see if there is some exception there.
Edit 2:
I see now that you are sending characters as RequestId. You should check if that URL can handle that kind of value. Since name is RequestId I'd say that there is big chance that there should be numeric only parameter. If that is correct, then it can happen that server side crashes when you try to open window and then nothing happens. Reason more to set try/catch block and test.
You might want to try Firebug lite, which will work for IE.
http://getfirebug.com/lite.html
The try/catch other people have mentioned is also a good idea. I think.
Additionally, is there any chance that the pop-up is trying to use a window that is already open but minimized. So it doesn't appear to be working but it's really just reloading the minimized window?