inspect script in chrome debug without losing ability to scroll webpage - google-chrome

When I have some breakpoints set up in a script google chrome removes the ability to scroll the webpage, saying at the top of the screen Paused in debugger. Is there a way to disable this so that I can look at elements in various parts of the page, while also looking at the script in the debugger?

Taken from here.
An easy workaround for the scrolling lock-up is to just jump to the console, and:
window.scrollTo(0, 800). (Replace 800 as needed)

You can click on the Elements tab and then hover over the HTML to the element you are interested in and right click to "Scroll into view". Not the most natural and fast, but it works...

Related

How can I inspect html element that disappears from DOM on lost focus?

I'm trying to inspect CSS properties from an input into a table cell. The input appears on click and disappears on lost focus, as when I try to inspect it.
How can I do it to don't lost focus while I move to another window (the inspector)?
In Chrome browser, open Developer Tools and select Elements tab, then
open the contextual menu of the parent node of the element you want to inspect, in the contextual menu click on Break on > Subtree modifications.
Afterwards you just need to click on the page and you'll get on the inspector without losing focus or losing the element you want to inspect.
In chrome devtools settings, there is an option named Emulate a focused page which is disabled by default. After enabling this option, if you click anywhere on the devtool window, it wouldn't cause loss of focus on any element in the DOM.
For Chrome version >= 86:
Open devtools and then press Command+Shift+P (Mac) or Control+Shift+P (Windows, Linux) to open the Command Menu. Start typing Rendering in the Command Menu and select Show Rendering. There you can enable Emulate a focused page.
After that, just click on any element to focus, and then click anywhere on the devtool window. You would see that element doesn't lose the focus. So now you can easily inspect or debug.
For Chrome version < 86
Go to devtool settings -> preferences and under Global option, enable Emulate a focused page.
You can capture the disappearing element if you pause JavaScript execution without moving the mouse. You can do so with a keyboard shortcut or by triggering a debugger statement. This works for elements whose appearance is controlled by JavaScript, rather than CSS :hover (if CSS, see Dumba F.'s answer).
Keyboard shortcut
This approach works for pages which don't use JS to trigger special behavior on keypresses. These instructions are for Google Chrome, but can be adapted to other modern browsers:
Open up Developer Tools and go to Sources.
Note the shortcut to pause script execution—F8 (there may also be another shortcut depending on your OS).
Interact with the UI to get the element to appear.
Hit F8.
Now you can move your mouse around, inspect the DOM, whatever. The element will stay there.
debugger statement
To trigger a debugger statement which executes while the hovered element is visible, use setTimeout:
Open the JS console, and enter:
// Pause script execution in 5 seconds
setTimeout(() => { debugger; }, 5000)
Cause the hover to open and wait for the script execution to be paused.
(Same as Nick Farina's answer)
If all else fails, type this in the Console:
setTimeout(() => { debugger; }, 5000)
Then you've got 5 seconds (or change the value to anything else) to make whatever you want to debug appear.
None of the other answers worked for me - the DOM tree kept getting modified (i.e. stuff I care about disappeared) right before the script paused.
Not sure if this works in your situation but normally (and in every case worth to mention in this regard as it is a great tool) in Chrome Developer Tools you can simulate element states and one is also :focus.
To do so go to the Elements tab in the Developer Tools and make sure you are in the Styles section on the right (this should be the default location when you start the Developer Tools). Now just beneth the Styles in the top right corner you have an icon Toggle Element State. When you click it you can simulate :active, :hover, :focus and :visited for the element you selected on the left in your code view.
In Chrome on the developer tools page for the page under test... click the options menu and open settings for preferences... under DevTools enable 'Emulate a focused page'
Then in the test page cause the elements to appear. This worked to keep my popup search results is focused to stay on the screen so I could work with it.
Not a real solution, but it usually works (:
Focus the element
Right click for context menu
Move down to developer tools
I had a very difficult situation and no answer was working from here (I didn't verify the answers changing the container, which is the body for me, or the original event, because I don't know that). I finally found a workaround by breaking via the Control Event Listener Breakpoints in Chrome Inspector. Maybe that is also a cross browser way of breaking for complicated situations where even F8 or right clicking mouse hide the popup again:
Click right of element in chrome devtools ;-)
Paste the following Javascript in the browser developer console:
// Delayed console log of parent element with disappearing child element(s)
// Once code is trigger, you have 3 seconds to trigger the hidden element before it snapshots.
// The hidden elements should appear in the console ready to inspect.
var timer = 3000; //time before snapshot
var parent_of_element_to_inspect = 'div.elementcontainer'; //container of element to snapshot
setTimeout(function(){
console.log(document.querySelector(parent_of_element_to_inspect).cloneNode(true));
},timer);
I have a quicker fix since I'm not very good with using tools, here's what i do.
event.originalEvent.preventDefault();
event.originalEvent.stopImmediatePropagation();
event.originalEvent.stopPropagation();
If you open Chrome DevTools and then trigger the element inspector using keyboard shortcuts, it should solve the problem.
Mac: Cmd+Opt+J and then Cmd+Opt+C
Windows: Ctrl+Shift+J and then Ctrl+Shift+C
[

"Inspect" a hover element?

Note: I've read similar threads, but none quite my issue - I can right click on it fine, it just then disappears.
I find 'Inspect Element' an invaluable tool in Chrome, however I'm having trouble using it for sub-menu for an element on my nav bar, which pops up below on hover of its parent item.
The popup (or down) isn't quite styled how I'd like, so I right-click > inspect element to see what's coming from where exactly, and get a better idea of how to achieve my desired effect.
However, as soon as I move my mouse away from the menu, it's gone; thus I can't select different elements in the inspection pane, and see which area is highlighted at the same time.
Is there a way around this, without changing the menu, so that it stays 'popped up' once activated?
If the hover element is triggered by JS (if triggered by CSS :hover, see gmo's answer), you can inspect it if you pause script execution. This is a much simpler way of freezing the DOM than the other answers suggest. You can pause script execution without losing the hover element as follows:
1. Via a keyboard shortcut
Here's how you do it in Chrome. I'm sure Firefox has an equivalent procedure:
Open up Developer Tools and go to Sources.
Note the shortcut to pause script execution—F8 (there may also be another depending on your OS).
Interact with the UI to get the element to appear.
Hit F8.
Now you can move your mouse around, inspect the DOM, whatever. The element will stay there.
2. Via a delayed debugger statement
Some web pages attach keydown / keypress / keyup event listeners which interfere with the shortcut above. In those cases, you can pause script execution by triggering a debugger statement while the hover is open:
Open the JS console, and enter:
// Pause script execution in 5 seconds
setTimeout(() => { debugger; }, 5000)
Trigger the hover and wait for the debugger statement to execute.
If the hover effect is given with CSS then yes, I normally use two options to get this:
One, to see the hover effect when the mouse leave the hover area:
Open the inspector in docked window and increase the width until reach your HTML element, then right click and the popup menu must be over the inspector zone... then when you move the mouse over the inspector view, the hover effect keep activated in the document.
Two, to keep the hover effect even if the mouse is not over the HTML element, open the inspector, go to Styles TAB and click in the upper right icon that says Toggle Element State...(dotted rectangle with an arrow) There you can manually activate the Hover Event (among others) with the checkbox provided.
If it's not clear at all, let me know and I can add a few screenshots.
Edited: screenshot added.
And finally and as I say at the begining, I only be able to do this if the hover is set with CSS:HOVER... when you control the hover state with jQuery.onMouseOver for example, only works (sometimes), the method One.
Hope it helps.
What worked for me is selecting the specific a tag I wanted to inspect and configure it to break on attribute modification:
After doing the above, I would again normally select that a tag then the dropdown will automatically stay as-is even when I mouseover to other places like Inspect Element, etc.
You can just refresh the browser when doing inspecting the menu dropdown elements to go back to normal state.
Hope this helps. :)
You can also do this in the javascript console:
$('#foo').trigger('mouseover');
An that will "freeze" the element in the "hover" state.
Here's how I do it with no CSS changes or JS pausing in Chrome (I am on a Mac and do not have a PC in front of me if you are running on Win):
have your developer console open.
do not enable the hover inspection tool yet, but instead open up your desired sub menu by moving your mouse over it.
hit Command+Shift+C (Mac) or Ctrl+Shift+C (Win/Linux)
now the hover inspection tool will apply to the elements you have opened in your sub-nav.
Open Inspect element
Now go to elements now on right side and select hover
It will show all hover effects
Not sure if it was present in previous browser revisions, but I just found out this extremely simple method.
Open the inspector in chrome or Firefox, right click on the element you are interested in, and select the appropriate option (in this case: hover).
This will trigger the associated CSS.
Screenshots from Firefox 55 and chromium 61.
I needed to do this, but the element I was trying to inspect was added and removed dynamically based on hover state of another element. My solution is similar to this one, but that didn't quite work for me.
So here's what I did:
Add simple script to enter debugger mode upon mouseover of the element that triggers the hover event you're concerned about.
$(document).on('mouseover', '[your-hover-element-selector]', function(e) {
debugger;
});
Then, with the dev console open in Chrome, hover over your element, and you will enter debugger mode. Navigate over to the sources section of the dev tools, and click the "Resume script execution" button (the blue play-like button below).
Once you do that, your DOM will be paused in the hover state, and you can use the element inspector to inspect all the elements as they exist in that state.
I found a very simple way to do this if for some reason you have problems with script pausing:
Open Dev Tools on "inspect"-tab.Hover to make the pop-up appear.Right-click on the desired element in your pop-up and press 'Q' (in Firefox) to inspect that element.Use keyboard to navigate: Arrow Up/Down: Move between elementsArrow Left/Right: Collapse/ExpandTab/Shift+Tab: Move between inspector and CSS rules and inside CSS RulesEnter: Edit CSS Rule
Excellent stuff!
Thank you to gmo for that advice. I did not know about those attribute settings massively helpful.
As a small revision to the wording I would explain that process as follows:
Right Click on the element you would like to style
Open 'Inspect' tool
On right hand side, navigate to the small Styles tab
Found above CSS stylesheet contents
Select the .hov option - This will give you all the settings
available for the selected HTML element
Click and Change all options to be inactive
Now Select the state that you would like to tweak - On activation of any of these, your Stylesheet will jump you directly to those settings:
Styles - Tweaking Filters - Interactive elements
This information was a lifesaver for me, cannot believe I have just heard about it!
Change the CSS so that the property which hides the menu isn't applied while you work on it is what I do.

Chrome 'paused in debugger' issue

I don't know what I've switched on (by accident) but every time I have the Inspect Element area open and then try to click anything on the webpage not within the Inspect Element area (especially something jQuery related like a slideshow for example) it greys the page, shows a message saying 'Paused in debugger' and then opens a jQuery file within the Sources section of Inspect Element.
Within the 'Call Stack' area, it shows a message saying 'Paused on a "click" Event Listener'.
I don't remember switching this feature on but I'm keen for it to be switched off.
I know this question has been asked before - I thought I'd found the answer when everyone suggested we look to see if the 'Pause' option is switched on (blue). However, it's not switched on, it's grey not blue or any other colour and when I hover over it, it says "Don't pause on exceptions. Click to Pause on all exceptions".
You might also check the Source tab, check under the Event Listener Breakpoints panel if you've set any breakpoints under 'Mouse'.
This can also cause the issue
Break Point icon at top left should be blue like this(For Deactivate BreakPoints)
Should not grey like this
Found solution here, if the little octagonal stop/pause sign (at lower left of Chrome "Sources") is colored (blue or purple), you need to click on it until it's black again.
It did drive me nuts for a short while.....scroll all the way to the bottom of breakpoint window and you'll find XHR Breakpoints & under it there is the Any XHR checkbox...
Goto the sources tab and check all breakpoints.
Go to Elements tab and remove all breakpoints from right pane under DOM Breakpoints
One possible cause, it that you've enabled the "pause on exceptions" (the little stop-sign shaped icon with the pause (||) symbol with in in the lower left of the window). Try clicking that back to the off/grey state (not red nor blue states) and reload the page.
For me, I resolved it by temporarily disabling the Chrome Bitwarden extension.
You could check to see in the Sources tab in the devtools panel to see what is causing this error, it could be an extension.
To open the devtools panel on Chrome, press the F12 key.
For Visual Studio Users, just go Tools>Options>Debugging and make disabled it

Chrome behaves differently when pressing reload v pressing enter in URL field

Was just trying to cobble a quick site together as a favour for my sister. It's based on a template she bought and I've just quickly bunged her copy/pictures in, so I'm aware the markup is far from perfect. That said, I can't see how it would be causing the following issue...
The template uses a jQuery plugin called jScrollPane to make the content sections scrollable. Sometimes however, in Chrome (v20) this doesn't work - it doesn't let you scroll all the way down.
What's really odd though, is the pattern I've found that seems to effect whether it works or not. Try the following
Go to http://mattandkate2012.co.uk in Google Chrome - click 'Ceremony' - can you scroll down far enough to see the map? I can't.
Press the reload icon, click 'Ceremony' - can you scroll down? I can't.
Select the URL in the browser URL bar, press enter - can you scroll down? I can now!
Does everyone else get the same results as above, and do you have any idea why pressing enter in the URL bar has a different effect to the reload button?
This functionality works fine in Firefox and even IE!
Thanks
Pete
From a very quick look I guess it's because the section contains an image and you aren't re-initialising jScrollPane once the image loads. See:
http://jscrollpane.kelvinluck.com/image.html
The difference between refreshing and pressing enter in the location bar is that the cached image is shown when you press enter in the location bar...
I would suggest moving the call to $('.content').jScrollPane({showArrows: true}); to inside the $(document).ready block - if you call it before the document is ready often images or other elements won't have loaded and so the height of the containers will be wrong.

Open a new browser window WITHOUT using target="_blank"

Every solution I've seen so far for opening a new browser window uses the target property in to set it to "_blank". This is frustrating because in some browsers it only opens a new tab AND combine that with the auto-resizing behvaiour at http://www.facebook.com/connect/prompt_feed.php?&message=test, it basically mangles my browser whenever I try updating my status from my site.
How can I be sure to open a new window when a user clicks on a link?
Thanks!
Trindaz on Fedang
Popups are windows, they just have some features disables. You can make a popup act like a regular window by enabling these features. For example, if you open a popup with
window.open('url', 'name', 'width=500, height=500, status=1, toolbar=1, location=1, menubar=1, resizable=1');
the window will have a toolbar, a URL bar, a status bar, menus, and it will be resizable. It will the same as any other window.
Keep in mind, however, that many browsers block window.open() under some conditions, and some of them will open new tabs if you specify a lot of features. Some are weird about it too; Chrome, for example, uses scroll bars on popups by default, but if you specifically tell it to use scroll bars in a popup (using scrollbars=1), it will open in a tab instead.
So basically there is no way to be completely sure that your page will always open in a new window, because browsers all handle this stuff differently, users can change settings too. The code above is probably your best bet if you have to have a new window, but you might want to look into other options.
window.open(URL,name,specs,replace)
function newwindow()
{
myWindow=window.open('','','width=300,height=300');
myWindow.document.write("<p>This should open in a popup</p>");
myWindow.focus();
}
There is a legitimate reason for using Target=_blank that everybody has completely overlooked, and that is when a website is written as a BOOK with chapters/pages and the Table of Contents must remain intact without using the BACK button to reload the previous page (Table of Contents). This way all a surfer needs to do is close the Target Page when finished reading and they will be back to the Table of Contents.
Lucky for us that HTML5 has reinstated the Target="_blank" code, but unfortunately the "Block Popups" must be unchecked for it to work.