Execute Javascript code in browser via xJavascript - javascript

I am looking for how to execute javascript code in the URL bar via xJavascript.
The standard way would be xJavascript:JAVASCRIPTCODEHERE, you would remove the "x" and it would execute the code, but that is not working.
Am I doing it wrong, or is no longer possible?
Please help!

I'm not sure what browser you are on but this is what I use:
javascript: (() => { document.title = "Hello World";})();
It also might not be working because you are running it on a new tab (which doesn't work for chrome)

If you are using this feature frequirently, make a bookmark with javascript:... code.
If you want to run some random JS while editing this JS, use Devtools (F12 or Ctrl+Shift+I in browser), Sources tab on top, Snippets tab on left. Snippets are persistent, editable, may run on any page.
If you want to run the same code on every page of a website, try https://chrome.google.com/webstore/detail/user-javascript-and-css/nbhcbdghjpllgmfilhnhkllmkecfmpld or Tampermonkey

Related

How do I able to see the source code of this website www.samy.pl?

This website (www.samy.pl) uses some technique so that no one can inspect the code (Ctrl+Shift+I) or view source (Ctrl+U). It can detect if you have opened the console or inspector the code automatically changes.
How this is possible?
You could always save the website.
In chrome open the menu -> more tools -> Save page as..
You should be able to run the html file in chrome, and use Dev Tools without it blocking you.
There is a console "clearing" API that is mentioned in this answer.
Here's what I think is happening:
First, I think Google Chrome DevTools emits an event when it is open/launched.
The page author listens for this 'launch' event with the following handler logic:
Run a chrome.devtools.inspectedWindow.eval DevTools inspection API
Set document.body.innerHTML to the winky-face div
Also, a setInterval that executes a console.clear() before the console.log() of "no source for you".
I also inspected the EventListeners tab of Chrome DevTools while reading the "no source for you"-page.
Unfortunately, the two event listeners you can view don't seem to do anything useful:
one returns false
the other wires together forms and their associated submit actions.
Hope this helped
hahaha, this is a good one, you should not expect less from samy!
Now I see why people think it is the wrong answer (the source get replaced if you do otherwise)
1.Navigate to site with inspector open there you end up with "No source for you! You found easter egg #7."
2.and then check the source to find Easter egg #2:
view-source:https://samy.pl
you will see:
/*
No source for you! Easter egg #2
*// AFTER SOME LONG WHITE SPACES HERE /.source.replace(/.{7}/g,function(w){document.write(String.fromCharCode(parseInt(w.replace(/ /g,'0').replace(/ /g,'1'),2)))});
This is the way he loads the site(by injecting js), by replacing two type of white spaces for 1 and 0 and parsing that to char code by some regex and then that to string of course :D
https://de.wikipedia.org/wiki/Whitespace_(Programmiersprache)
If you paste that part to a js console, you will get the tags that loads the page.
ps. to see the rendered source, just load the page normaly and hit F12 after disabling javascript.
Have fun!
Create an index.html somewhere, containing an <iframe src='https://samy.pl/'>. Load it in your browser and then open devtools. You will see the source inside the iframe.
Update:
Go to view-source:http://samy.pl which is the link of what the view source right click brings you to. It only works on Chrome I think.
If you are using chrome, go to the menu at the top right. Then go to more tools, and click developer tools.
After a lot of tinkering and speculating together, my roommate succeeded in the end with quite a naïve approach.
Simply open the Chrome devtools and copy out the source before it gets replaced. Giving Chrome processes low priority and doing some heavy-lifting with your CPU (compilation or other) helps.
Chop, chop.
Ah! I have found an extremely easy way to do it.
1. Open Firefox (Chrome only shows you part of it).
2. In the URL bar, type in javascript:alert(document.documentElement.outerHTML);
3. Press Enter.
4. Voilà!
New Way to find the source code! But its complicated!
Open a new tab.
Open Devtools (Inspect Tab)
Click On Toggle Device toolbar (the mobile like icon)
Click on "No Throttling" to slow down the page loading time
Select "Low - Tier Mobile"
Open the page!
When you see the icons appear on the page, you can now see the source code! :)
sorry very late
but i think i have the answer
He used this node package
to which he has contributed and forked too
the package docs say that it wont work if the devtools are undocked
You can simply use the developer tools in almost all the browsers. Just Press F12 and the developer tools section will be there.
Thanks

How to debug non-dynamic script after dynamic script loads on the same page

This answer https://stackoverflow.com/a/10929430/749227
to this question Is possible to debug dynamic loading JavaScript by some debugger like WebKit, FireBug or IE8 Developer Tool? is spot on for debugging dynamic scripts.
The issue I am facing is that I have a page that has a script on it, and after it loads an ajax request fires which returns with some HTML and a script that get put into the page. With the //# sourceURL=myDynamicDocumentFragment.html bit added, I can debug the dynamic script just fine.
But once it's loaded, then the other script that is part of the outer page that initially loaded goes off the rails. I can set breakpoints on blank lines and can't set them on legitimate lines. The debugger will stop on them but it won't be at the place in the code where I'd expect.
What it appears to be is that the dev tools window is showing the original script, and the debugger itself is running on something else - some updated version of code that includes both the outer page's script and the dynamic script that was added later. Or maybe it just hiccups with respect to line numbers it's displaying and what those map to in the code it's actually running.
I wish I had a good simple code snippet to demonstrate the issue, but I don't. Has anyone seen this, and does anyone know of a way to have Chrome 'refresh' the dev tools scripts/debugger without refreshing the page? (it has to be w/o refreshing the page since things work fine when the page loads - it's only after the dynamic script is dropped in that the wheels come off)
Note: I've tagged with Chrome since that's what I'm using (v 38). I don't know how other browsers fare.
You can find scripts injected into head or evaluated, here is a break point added on youtube evaluated (another js file).
You can find this in chrome as well, adding console.log (click on message shown), and voila you have source code you can add break points.
Here mozila print debugging/breakpoint over evaluated script on utube page:
Update
Sorry, I understand chrome was out of the scope, my engrish :)
How I did debugging on chrome over injected scripts, but there are cases when you cannot attach to execution if script is active (page load plus few milliseconds), you need to search for workarounds.
Added this at the begin of the script injected:
//# sourceURL=jseinjectedsource.js
console.log("evaluated");
and voila console:
Better check this way better than my explanation chrome developer
Check to see if your script is using a source map (if you're using TypeScript this is typically on by default for VS projects).
I've found Chrome to be really bad with source maps, often refusing to update them, or stop displaying them after the source map line is removed from the code.

How to modify javascript code at run time?

Is there a way to modify JavaScript code while debugging? Visual Studio has "Edit and Continue", and similar hot swapping of code can be done in Java and other languages. Can this be done with JavaScript, and if so, how?
Chrome, Safari, and some other WebKit-based browsers contain a feature in the Web Inspector known as Live Edit. If you go to the Scripts panel and are stopped on a breakpoint (or maybe even if not stopped on a breakpoint — I'm not sure), you can double click on a line and start editing that line. The changes you make will take effect on the script.
With Chrome Developer tools, this is super easy.
Just pop open inspector, click on the scripts tab, select which one you want from the dropdown menu and then you are free to edit the script and add in breakpoints. If you refresh the page, your breakpoints will stay there.
If you watch this talk but Paul Irish, he shows how you can edit a script on the fly
http://paulirish.com/2011/a-re-introduction-to-the-chrome-developer-tools/
also good:
http://blip.tv/jsconf/jsconf2011-paul-irish-5382827
If you're talking about while debugging, it's very easy to modify the running code. In your debugging console, you can enter in Javascript expressions and it will run in the context of the window, which contains all the objects and functions of your code, so you can swap them out by redefining them.
Because JavaScript can modify the DOM the you essentially have to change the JavaScript file, save it and reload. For me, I like IE so I run the webpage in a browser NOT IN DEBUG mode. Then you can change the script files, SAVE them. switch back to the browser and reload (F5) to see your changes. Supposedly IE 11 has this ability (probably like Chrome which is essentially what I am doing, changing saving reloading from what I can tell) but I can't get it to find, let alone open a js file. Super poor UI. I'm guessing the browser to open the file icon is but it is always grayed out.

How to write and run scripts in the Google Chrome Javascript Console?

I recently switched from Firefox to Chrome and I (probably) missed an important feature. I was used to test javascript snippets on FF from within the Firebug console this way: open the console, write the script and finally press CTRL + Return to execute the code.
It seems not possible to do the same in Chrome console, as when I type some code there and press return to start a new line the code is executed immediatly.
Is there a way to replicate the Firefox behavior on Chrome?
Thanks.
It seems that there is no explicit “multiline mode”.
But you can:
Paste code (it will preserve multiline)
Shift + Return to add a new line without executing the script
Related bugs:
https://bugs.webkit.org/show_bug.cgi?id=30553
http://code.google.com/p/chromium/issues/detail?id=72739
You can also hit Shift + Enter to start a new line without running the code in Chrome's console: https://developers.google.com/chrome-developer-tools/docs/tips-and-tricks#multiline-commands
Install Firebug Lite for Google Chrome. It has got a console.
Don't look for a full fledged Firebug. You will be disappointed :)
Oops,I didn't read properly at first. My bad!
In Firebug Lite, take Console. Then you will see a tiny red up-arrow at the right corner.
Click on it and you will get a multi-line console. Won't you?
I recommend this:
Write debugger; and hit Enter, in the console tab
This takes you to the Sources tab; if not, make sure debugger breakpoints are active
Now you can write whatever you want in the Sources tab, which acts like a full IDE with features like newline and indentation
Select any part of your code to run, and right-click, choose Evaluate in console
Better way of doing this using Chrome featue i.e Snippets where you can write javascript and save it in chrome developer console.
Its available underneath source inside developers tools while inspecting element.
More info about the snippets can be find on this link.
It was available in Chrome canary and I guess now it is available in default chrome browser also.

why does firebug debugging sometimes work and sometimes not?

I want to debug a javascript file that is embedded in the HEAD element.
I navigate to the site, see the code, and make a breakpoint:
(source: deviantsart.com)
But when I click on Reload, the script disappears and it doesn't stop at the breakpoint:
(source: deviantsart.com)
Debugging was working earlier so I know it works in general. What do I have to do so that Firebug always debugs my script?
I've noticed this behaviour before as well. It seems that it can happen if you refresh the page while the debugger is running (i.e. after you've hit your breakpoint and are stepping through code). This is far from conclusive, just something I've casually observed over time.
Also, I try to avoid having multiple tabs open with firebug active, as it seems to get confused.
Edit: just thought I'd add that I've seen this manifest itself in a few different ways:
the external script file does not appear at all in the scripts panel.
the external script file appears but firebug doesn't "see" it. You know this has happened because the line numbers beside the code where a breakpoint can be set won't be highlighted (used to be green but now appear to be just a darker shade than other lines). I've seen this happen with inline javascript on a HTML page (horrors!) as well.
the external script file is there, but you can only see a single screen full of code. Where "screen full" is the firebug panel viewport.
shut down firefox and then restart. sometimes firebug gets confused. also make sure you have the latest version.
You need activate the script tab
I'm not sure that having a <script> inside <head> (as opposed to, inside <body>) is actually legal HTML. If it's not, as I suspect, you can't fault Firebug for not supporting it well...!-)
The bugs in script processing that I know about are 1) jquery dynamic loading of scripts fails, 2) new Function() cannot be seen, 3) some kinds of document.write() cannot be seen.
Firebug processes script files in series with Firefox. This means that Firebug must be active when the page loads and it means that any exception in the path will cause the files to be mis-processed. If you opened firebug before loading and you still see problems, then the most likely fix is to install Firebug in a new Firefox profile. This causes you to get a completely fresh set of default options and you run Firebug without other extensions. As you re-add other extensions, look for problems in seeing scripts: then maybe you will discover what extension is interfering with the code path for processing scripts. I know this is a pain in the neck, but so is JS debugging without source ;-). We are working on testing with more Firebug and Firefox extensions installed to try to reduce these problems.
In our case it was the bundling of JS files.
It is not only FireFox, it is same for Chrome.
We moved the file out of the bundle and put it on the page where it needed to be referenced and it started working like charm.

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