How to inject JavaScript into a website through the URL bar? - javascript

Here is the JavaScript code I inject into the page:
javascript:{document.head.innerHTML+='<script>function inject(){alert("hello");}</script>';
document.body.innerHTML+='<button onclick="inject()">Run</button>';}
After running this code in the URL bar, I inspect the source code of the website. Both the button and the function definition are present, however pressing the button does not run the alert as one would expect.
What could be the problem?

some browsers no longer accept javascript: directly from the location bar, they need you to call the script from a bookmarklet
your syntax smells of wishful thinking. What you try here would never work that way
This syntax:
javascript:(function() { var s = document.createElement("script"); s.src="somejsurl.js";document.getElementsByTagName("head")[0].appendChild(s)})()
might be a better start
To get this to execute, you would need to create an html page with
Exec
using single quotes inside the href code and load and drag the "Exec" to the bookmarks
While testing, Chrome and Firefox has a command line you can use
If you want to create the script and not load it, you would need to inline the script in the button you created:
javascript:(function() { var b = document.createElement("button"); b.onclick=function() { alert('hello')}; b.innerTHML='Hello';})()

Some browsers have decided to limit javascript use in the URL bar for security purposes...

Related

Chrome Extensions: Use a content script to modify existing scripts on a web page?

I'm creating a chrome extension that needs to hook into another script that already exists on my target web page. For simplicity's sake, I'm trying to find the following existing script element on a page and add a console.log() to it.
<script type="text/javascript">
var viewModel = new ScenePlayViewModel('', 'Ace', false);
viewModel
.load('jgWJJ2qsxx')
.then(function () {
sceneDOM = new SceneEditDOM2(viewModel.scene());
sceneDOM.init();
viewModel.isSubmitViaShareUrl(false);
viewModel.isSubmitViaUnityPackage(false);
console.log("HOOK INJECTED"); <--------------------------------------------- line to add
});
</script>
I've tried a number of solutions but none of them have seemed to work. For example, I've tried using a content script to find the script and replace the text, but it appears to run the pre-change script instead of my modified code.
// replaces javascript on website, but doesn't run new version
var scriptLoadScene = $("script:contains('new ScenePlayViewModel')"); // find the script
scriptLoadScene.text("console.log('Hello World')"); // change the text
What should I do? Basically, I'm just trying to change/add scripts to the web page to add more features.
This doesn't exactly answer your question, but hopefully will help you find a solution.
First - hopefully someone with more knowledge than me will confirm or discredit this - from my understanding, the script code is only run once, on page load, unless otherwise triggered by some event. Since Chrome extensions are triggered after the page has loaded, this script will have already been run, and anything inserted after won't run unless triggered.
I suppose you could always call the function again after you've edited it, but I don't have the knowledge or experience to predict what would happen then.
In my experience, I've just added my own '' tags with the code I wanted to run by writing them into the DOM, either into the '' or '' element.
Best of luck.
-brent

How To Access and Click Button PhantomJS

I am trying to automatically download a plugin on my wordpress site by implementing phantomJs. For some reason, I cannot seem access the download button (shown below)
This is the HTML code to the image (with domain sensitive information blurred out for security purposes)
So far, I have tried accessing this element by using the following code:
function() {
page.evaluate(function() {
let mainLink = document.querySelector('a[data-slug="better-wp-security"]')
mainLink.click()
})
}
Some things to mention:
This function, as it is part of a larger file, will NOT execute until the page has finished loading.
PhantomJS is executing correctly, there are no problems with permissions
The script before-hand is properly accessing the install plugins page, which I verified by capturing screenshots before trying to click.
I have defined click earlier int he file, it works perfectly.
Any ideas how I can accomplish this? Thanks all!
ADDED INFORMATION:
It seems as if the path from the main div element is as follows:
#the-list .plugin-card plugin-card-better-wp-security .plugin-card-top .action-links .plugin-action-buttons .install-now button
I imagine the solution to this question has something to do with this sequence.
I was able to accomplish this by now going after the data-slug attribute, but rather going after the href element itself. Although I can't generate my own wponce value without the use of the Rest API, I was able to search the document to find an href that contained certain parts of the url. This is the final code below:
document.querySelector('a[href*="action=install-plugin&plugin=better-wp-security"]').click()
That's it! Simple and easy!

How to make a JS script run in all tabs from a given window in Firefox?

I am a newbie and a Firefox user.
I want to change the tab's titles to something that's easier for me to read. On a given tab, I can easily modify in the console document.title to a name output by my script.
Is there a way to make this script run in all tabs opened in a given window, or must I open the console in each tab and run the script there?
If possible, I'd prefer answers that don't need SDK, that can only use the regular console/options from Firefox.
#Arber Sylejmani is right, I think it's not possible even via console (in contrast to an embedded JS). But #Alexander O'Mara nailed it, I just had to install a Greasemonkey addon. Then you can do the scripts you like and apply it to all tabs.
Example:
Greasemonkey's icon -> "New user script" -> name: "Change title" -> namespace: "Change title" -> include: (here comes a list of URLs that will trigger the script if the tab uses one of those URLs. For example, if I want to make the script run only on tabs from stackoverflow, then:) " https://stackoverflow.com/* " (without quotes)
Then comes a regular JS script. Say: document.title = document.location.href; . Or whatever. This is a good tutorial: http://www.techradar.com/news/internet/the-beginner-s-guide-to-greasemonkey-scripting-598247

Link that opens a NEW page and runs javascript

I would like to know how to open a page, and then on that page, run javascript (that is set by the link on the first page). I have tried this:
LINK DISPLAY NAME HERE
Does anyone know how to achieve this?
If the new page is a page whose code you control, then you can pass a query parameter to the new page via the link and you can have the javascript in the new page check for that query parameter and, if found, run some code in the page upon page load.
LINK DISPLAY NAME HERE
And the startup javascript in the new page would check for the runOnStartup query parameter and run some code based on its value.
If the new page is in the same origin as your current page, then you could open the new page in a new window and then after it opened, you could call a function in that new window. But, your previous page would have to still be running in order to do that.
If the new page is in a different origin and you do not control the code in that new page, then you cannot do what you're asking for browser security reasons.
This is possible, no problem.
Note that IE has weird incompatibilities in this area of the DOM.
<!DOCTYPE html>
<html>
<head></head>
<body>
<a id="foo" href>Click me!</a>
<script>
document.getElementById('foo').onclick = onFooClick;
function onFooClick(e) {
var scriptToInject, popUp, node, importedNode;
scriptToInject = 'document.body.innerHTML = "Hello from the injected script!";';
popUp = window.open('about:blank');
node = document.createElement('script');
node.textContent = scriptToInject;
importedNode = popUp.document.importNode(node, true);
popUp.document.body.appendChild(importedNode);
}
</script>
</body>
</html>
The above works in Chrome, Firefox and Safari on a Mac.
Warning: Do not use the following code in any remotely-production related machine. It is trivially susceptible to XSS and allows anybody to run any JS code on your website. This means that a malicious website could trivially steal your users' identities and other sensitive data. I highly recommend I recommend against using the method described in this answer in any form/
Page 1
Page 2
<script>
var javascript = <?=$_GET['javascript'] ?>;
eval(decodeURIComponent(javascript));
</script>
If you don't have PHP, use:
var javascript = window.location.href.match(/[^?=]+$/)[0];
*I haven't tested this code so it may need some fixing. I am also assuming you own both pages. If the target page isn't yours, you can't run JavaScript on it for security reasons.
to URL encode your JavaScript, go here, type your JavaScript, and hit encode.

Is possible to debug dynamic loading JavaScript by some debugger like WebKit, FireBug or the IE8 Developer Tool?

From my recent question, I have already created some JavaScript functions for dynamic loading of a partial view. But I can't debug any dynamic loading JavaScript. Because all of the loaded JavaScript will be evaluated by the "eval" function.
I found one way to create new JavaScript by using the following script to dynamically create the script into the header of current document. All loaded scripts will be displayed in the HTML DOM (and you can use any debugger to find it).
var script = document.createElement('script')
script.setAttribute("type","text/javascript")
script.text = "alert('Test!');";
document.getElementsByTagName('head')[0].appendChild(script);
By the way, most debuggers (IE8 Developer Toolbar, Firebug and Google Chrome) can’t set breakpoints in any dynamic script. Because debuggable scripts must be loaded the first time after the page is loaded.
Do you have an idea for debugging when using dynamic script content or a dynamic file?
Update 1 - Add source code for testing
You can use the following xhtml file for trying to debug someVariable value.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Dynamic Loading Script Testing</title>
<script type="text/javascript">
function page_load()
{
var script = document.createElement('script')
script.setAttribute("id", "dynamicLoadingScript");
script.setAttribute("type","text/javascript");
script.text = "var someVariable = 0;\n" +
"someVariable = window.outerWidth;\n" +
"alert(someVariable);";
document.getElementsByTagName('head')[0].appendChild(script);
}
</script>
</head>
<body onload="page_load();">
</body>
</html>
From answer, I just test it in FireBug. The result should be displayed like below images.
Please look at the "dynamicLoadingScript" that is added after page load.
But it is not found in the script tab of FireBug
Update 2 - Create Debug Breakpoint in dynamic loading script
Both of the above images show inserting "debugger;" statement in some line of the script can fire a breakpoint in the dynamic loading script. However, both debuggers do not show any code at breakpoint. Therefore, it is useless to this
Thanks
It would also be possible to use chrome for the same. Chrome has a feature where you can specify a parser attribute and make the piece of dynamic JS appear as a file which can then be browsed to and break points set.
the attribute that needs to be set is
//# sourceURL=dynamicScript.js
where dynamicScript.js is the name of the file that should show up in the script file browser.
More information here
Paul Irish also talks about it briefly in his excellent talk on Tooling & The Webapp Development Stack
Try adding a "debugger;" statement in the javascript you're adding dynamically. This should cause it to halt at that line regardless of breakpoint settings.
Yes, It is (now) possible to debug dynamically loaded JavaScript using Google Chrome!
No need to add extra debugger; or any other attribute for dynamically loaded JS file. Just follow the below steps to debug:
Method 1:
My tech lead just showed a super-easy way to debug dynamically loaded Javascript methods.
Open Console of chrome and write the name of the method and hit enter.
In my case, it is GetAdvancedSearchConditonRowNew
If the JS method has loaded then it will show the definition of the method.
Click on the definition of the method and the whole JS file will be opened for debugging :)
Method 2:
As an example, I'm loading JS file when I click on a button using ajaxcall.
Open network tab in google chrome dev tools
Click on a control (ex. button) which loads some javascript file and calls some javascript function.
observe network tab and look for that JS function (in my case it is RetrieveAllTags?_=1451974716935)
Hover over its initiater and you'll find your dynamically loaded JS file(with prefix VM*).
Click on that VM* file to open.
Put debugger whereever you want in that file :D
I'm using google chrome for that purpose.
In chrome at scripts tab you can enable 'pause on all exceptions'
And then put somewhere in your code line try{throw ''} catch(e){}. Chrome will stop execution when it reaches this line.
EDIT: modified image so it would be clearer what I'm talking about.
I think you might need to give the eval'd code a "name" like this:
http://blog.getfirebug.com/2009/08/11/give-your-eval-a-name-with-sourceurl/
If you do, I think it's likely the debugger approach from "update 2" should work then.
UPDATE: the syntax for sourceUrl has been changed (# is replaced by #) to avoid errors on unsupported browsers (read: IE). Details
Using Chrome(12.0.742.112) with the code you provided plus a debugger statement like this
script.text = "debugger;var someVariable = 0;\n" +
"someVariable = window.outerWidth;\n" +
"alert(someVariable);";
works for me.
I need to modify some JavaScript (limiting scope of all jQuery selector to current partial >view div) before execute it.
May its more tangible if you bind the selector change to an event on your partial view instead of creating script elements in the html body ( doesnt feel right ).
You could do something like this
(function(j)(
var limiting_selector = '';
j(".partial_views").bind('focusin over',function(e){
limiting_selector = j(this).attr('someattr') // or j(this).data('limiting-selector')
}).bind('focusout out',function(e){
limiting_selector = '';
});
// And then go on with
// j(limiting_selector+' .someclass')
))(jQuery)
This code would always add a limiting selector to all jQuery select operations done while the mouse is in a certain element given the HTML isnt to messed up.
(Still seems hackerish, may be someone has a better solution)
cheers
In Firebug, you should be able to see that script after the page is loaded and the script is injected. When you do, you can set a breakpoint in the appropriate place, and it'll be preserved when you refresh the page.
Dynamicly loaded Javascript still has to be parsed by the browser this is where WebKit, or FireBug debugger is sat so it's subject to the debugger no matter what, i think this is the same for the developer tools in IE8,
So your code is subject is to the debugger so where your getting a problem will not be in that file or text if it does not error
The other thing is script.text = "alert('Test!');"; is not valid so it wont work in all browsers what you want is script.innerHTML = "alert('Test!');";
even though its innerHTML it means code inside the HTML Tags not the HTML inside just the most use people use it for this so it gets explained wrong
EDITED FOR UPDATE TWO
And on Second update using Chrome i did this
go to about:blank
Open the console up and past in
var script = document.createElement('script')
script.setAttribute("type","text/javascript")
script.innerHTML = "alert('Test!');debugger;";
document.getElementsByTagName('head')[0].appendChild(script);
then it will break and open the script tab with about:blank shown (nothing to see)
Then on the right hand side show the call stack list, then click on the second (anonymous function) and it will show you.
So on your file you will have a (anonymous function) that is the code your running and you will see the break point in there. so you know your in the right one.
Using Google Chrome (or Safari) Developers Tool, you can run JavaScript line by line.
Developer Tool > Scripts > Choose which script you want to debug > pause sign on the right side
Or set breakpoints by click the line number
One option I like to use it adding a console.log('') statement in my code. Once this statement appears in the console a line number is associated with it. You can click that number to go to the location in the source and set a breakpoint. The drawback to this approach is that breakpoints are not preserved across page reloads and you have to run through the code before you can add a debugger.

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