I am working on a site, which loads 100 of javascripts. In one page, I have a "iframe" which loading a youtube video. I see the "title" tag of the iframe is reset by some javascript. By doing some test, I see that javascript, find and replacing the iframe attribute by the tag name "iframe".
Can anyone help me, how to find who is replacing this iframe attribute?
<iframe src="/en-us/media/oembed?url=https%3A//youtu.be/C5oQYNDZtpI&max_width=500&max_height=281&hash=7G5DUR_fZxyPVcv3Js9TxsId_i6OkO8HjHIRYH650Jo" frameborder="5" allowtransparency="" width="500" height="281" class="media-oembed-content" title="iframe"></iframe>
Simply open Chrome-Developer tools, find the desired iframe in the DOM-Tree (or open it via context-menu Inspect element), right-click the element and select Break on -> attribute modification. After reloading the page, whenever an attribute of the DOM-node is changed, the developer tools will jump to the sources tab and show you the exact line in the causing javascript file.
In case the file is minified, you can click the {} icon in the bottom left in Sources-tab to formate the code for better readability.
I have a javascript file that was accidentally added to the admin side of our site. The javascript is below,
<script>
if (document.getElementById("errorTitle") != null && document.getElementById("errorTitle").innerHTML === "Insufficient Privileges") {
window.location.replace("/portal/InsufficientPrivileges");
} else {
window.location.replace("/portal/FileNotFound");
}
</script>
The problem is that this code runs on the admin pages so we are unable to remove it. If we disable javascript on the browser the page never renders, dynamic content. How can we disable this from running so we can upload the proper file?
You might be able to edit the page that contains the reference to the problem file. If you can just edit the page to jump over where that code is called with an if statement or goto.
If you can't edit the other pages then you can Use the debugger to change the code executed on the fly. Chrome and Firefox have debuggers that should be able to do this.
Specifically for Chrome you go into the object inspector (available via menus or right clicking on the page). Then you can see the HTML on the left window. You select the script tag of interest, you can right click and select delete or select "Edit HTML"
If the page redirects you before you're even able to edit anything, you can use automated tools.
Fiddler (Windows)
Fiddler lets you see all pages downloaded, and then you can have it send your browser a different page when it tries downloading any page you specify (AutoResponder feature). This way you can temporarily edit a page while you can fix it in the admin panel.
Greasemonkey (Firefox) or Tampermonkey (Chrome)
These plugins let you run JavaScript code on a page as soon as it gets to your browser. This will let you do things such as removing the script tag programmatically.
I am dynamically adding the content of "div" in jquery it is added in DOM. but in view page source i can't see dynamic content of an element
<div id="pdf"></div>
("#btn").click(function(){
$("#pdf").html("ffff");
});
how can i get updated page source after made dynamic changes. it is added in DOM but page source doesn't have the content ? why ?
Thanks,
Siva
The page source is the page source - a raw text file which cannot be changed. It is hosted on the server and it's obvious you can't made any changes to it. Once you visit a web page, your browser queries to read that text file and then it parses it to the DOM. When you do any javascript/jQuery magic like adding new html elements, you do it on the DOM.
that's just normal behavior, the source is allways the original source of the page and it doesn't show changes made after page load. If you want to check the source after changes use a tool like firebug or chrome developer tools.
EDIT:
As Johannes H stated you no longer require firebug since major browsers all include developer tools.
If you use Firefox you can get the "web developer" plugin, then view "generated source". This will show the jQuery added div.
When You are viewing the page source the javascript will not run, so the dynamic elements will not be added.
To get the sources you can use your browser developer tools:
click f12
choose the top element and press copy as html.
When I right click on the icon for my extension-in-development and click Inspect Popup (or when I click the icon and choose "Inspect Element") and look under the "Sources" tab, my .js file is nowhere to be seen - only a long list of inspect-able files like apitest, devtools, json_schema, etc. I can, however, find the code through the Elements tab by following the link in the .html file, but that doesn't bring to anywhere where I can actual debugging.
I've also loaded the "Hello, world" extension that Google's tutorial provides, and when I Inspect that one, its .js file is right there. I can't imagine what I've done differently from the tutorial example to cause this.
It's Chrome version 22.0.1229.94 run in a Linux VM. If there's any more information I should be providing, please let me know.
Type location.reload(true) in the console.
http://developer.chrome.com/extensions/tut_debugging.html
If I understand your question right,
Under the sources tab, there are two more tabs, one says Sources and the other says Content scripts. You need to click on the content scripts tab, and there you will find what you are looking for.
Okay So I figured it out, simply click on you extension icon, and a little dialog will pop up, then right click on it and click on inspect element. You can figure it out from there I reckon. (My other answer would be good if it was a content script, but this is a popup script.)
How do I "dynamically" edit JavaScript code in the Chrome debugger? It's not for me, so I don't have access to the source file. I want to edit code and see what effects they have on the page, in this case stopping an animation from queuing up a bunch of times.
I came across this today, when I was playing around with someone else's website.
I realized I could attach a break-point in the debugger to some line of code before what I wanted to dynamically edit. And since break-points stay even after a reload of the page, I was able to edit the changes I wanted while paused at break-point and then continued to let the page load.
So as a quick work around, and if it works with your situation:
Add a break-point at an earlier point in the script
Reload page
Edit your changes into the code
CTRL + s (save changes)
Unpause the debugger
You can use the built-in JavaScript debugger in Chrome Developer Tools under the "Scripts" tab (in later versions it's the "Sources" tab), but changes you apply to the code are expressed only at the time when execution passes through them. That means changes to the code that is not running after the page loads will not have an effect. Unlike e.g. changes to the code residing in the mouseover handlers, which you can test on the fly.
There is a video from Google I/O 2010 event introducing other capabilities of Chrome Developer Tools.
You can use "Overrides" in Chrome to persist javascript changes between page loads, even where you aren't hosting the original source.
Create a folder under Developer Tools > Sources > Overrides
Chrome will ask for permission to the folder, click Allow
Edit the file in Sources>Page then save (ctrl-s). A purple dot will indicate the file is saved locally.
This is what you are looking for:
1.- Navigate to the Source tab and open the javascript file
2.- Edit the file, right-click it and a menu will appear: click Save and save it locally.
In order to view the diff or revert your changes, right-click and select the option Local Modifications... from the menu. You will see your changes diff with respect to the original file if you expand the timestamp shown.
More detailed info here: http://www.sitepoint.com/edit-source-files-in-chrome/
Chrome Overrides
Open the JS file in the sources panel.
Right Click on script src URL > Reveal in Sources panel
Make sure "Enable Local Overrides" is checked.
Right Click anywhere in the JS file > Save for overrides
All Set!
Just edit the file, and save with CMD/CTRL + S. Now whenever you refresh the page, it'll use the modified file. (As long as the filename remains the same)
You'll know it's working if you see a purple dot in the file icon.
Place a breakpoint
Right click on the breakpoint and select 'Edit breakpoint'
Insert your code. Use SHIFT+ENTER to create a new line.
Pretty easy, go to the 'scripts' tab. And select the source file you want and double-click any line to edit it.
If its javascript that runs on a button click, then making the change under Sources>Sources (in the developer tools in chrome ) and pressing Ctrl +S to save, is enough. I do this all the time.
If you refresh the page, your javascript changes would be gone, but chrome will still remember your break points.
As this is quite popular question that deals with live-editing of JS, I want to point out another useful option. As described by svjacob in his answer:
I realized I could attach a break-point in the debugger to some line of code before what I wanted to dynamically edit. And since break-points stay even after a reload of the page, I was able to edit the changes I wanted while paused at break-point and then continued to let the page load.
The above solution didn't work for me for quite large JS (webpack bundle - 3.21MB minified version, 130k lines of code in prettified version) - chrome crashed and asked for page reloading which reverted any saved changes. The way to go in this case was Fiddler where you can set AutoRespond option to replace any remote resource with any local file from your computer - see this SO question for details.
In my case I also had to add CORS headers to fiddler to successfully mock response.
Now google chrome has introduce new feature. By Using this feature You can edit you code in chrome browse. (Permanent change on code location)
For that Press F12 --> Source Tab -- (right side) --> File System - in that please select your location of code. and then chrome browser will ask you permission and after that code will be sink with green color. and you can modify your code and it will also reflect on you code location (It means it will Permanent change)
Thanks
Just like #mark 's answer, we can create a Snippets in Chrome DevTools, to override the default JavaScript. Finally, we can see what effects they have on the page.
here's a gentle introduction to the js debugger in chrome that i wrote. Maybe it will help others looking for info on this: http://meeech.amihod.com/getting-started-with-javascript-debugging-in-chrome/
you can edit the javascrpit files dynamically in the Chrome debugger, under the Sources tab, however your changes will be lost if you refresh the page, to pause page loading before doing your changes, you will need to set a break point then reload the page and edit your changes and finally unpause the debugger to see your changes take effect.
I was looking for a way to change the script and debug that new script. Way I managed to do that is:
Set the breakpoint in the first line of the script you want to change and debug.
Reload the page so the breakpoint is being hit
Paste your new script and set desired breakpoints in it
Ctrl+s, and the page will refresh causing that breakpoint in first line to be hit.
F8 to continue, and now your newly pasted script replaces original one as long as no redirections and reloads are made.
Chrome DevTools has a Snippets panel where you can create and edit JavaScript code as you would in an editor, and execute it.
Open DevTools, then select the Sources panel, then select the Snippets tab.
https://developers.google.com/web/tools/chrome-devtools/snippets