Find out redirected location of Javascript source - javascript

My HTML page has a <script> tag, which embeds a Javascript source file indirectly through a PHP script, e.g.
<script src="http://my.server.com/myjs.php?version=1"></script>
Based on the parameters to myjs.php (version only being an example) the PHP file simply sets the location
header("Location: version/1/mynewfile.js");
and the browser then automatically loads mynewfile.js.
Unfortunately mynuewfile.js needs to know the URL where it is loaded from, e.g. http://my.server.com/version/1/mynewfile.js.
Without using redirection, the globally executed code in mynewfile.js simply inspects the src property of the first element. Unfortunately, this only returns http://my.server.com/myjs.php?version=1. How can mynewjsfile.js get the real (redirected) URI of the script?
Of course, the PHP file could "simply" read the JS file and set a global variable to the JS file, but redirection is a really elegant solution and should be kept if possible.

Related

Phantomjs: Modifying html dom before opening it as webpage

I need to process html files that have corrupted script files that are added to it via tag.
Im planning to remove all script tag present in the webpage via phantomjs.
But on opening the webpage via webpage.open(), phantomjs parse error is thrown since it cannot parse the JS content within the script tag.
Here is an example:
<html>
<head>
<script>
corrupted JS
if(dadadd
;
</script>
<body>
some content
</body>
</html>
Can someone help me on suggesting the right way to clean this webpage using phantomjs ?
It's not (easily) possible. You could download (not through opening the page, but rather making an Ajax request in page.evaluate()) the static html, then change according to your needs, then assign it to page.content.
This still might not work, because as soon as you assign it to page.content, you're saying that PhantomJS should interpret this source as a page from an unknown domain (about:blank). Since the page source contains all kinds of links/scripts/stylesheets without a domain name, you'll have to change those too in order for the page to successfully load all kinds of resources.
It might be easier to just have a proxy between PhantomJS and the internet with a custom rule to adjust the page source to your needs.

Executing a JavaScript file directly from the browser

This sounds like a trivia question but I really need to know.
If you put the URL of an HTML file in the Location bar of your browser, it will render that HTML. That's the whole purpose of a browser.
If you give it a JPG, or a SWF, or even PDF, it will do the right things for those datatypes.
But, if you give it the URL of a JavaScript file, it will display the text of that file. What I want is for that file to be executed directly.
Now, I know that if you use the javascript: protocol, it will execute the text of the URL, but that isn't what I need.
I could have the URL point to an HTML file consisting of a single <script> tag that in turn points to the JavaScript file, but for occult reasons of my own, I cannot do that.
If the file at http://example.com/file.js consists entirely of
alert("it ran");
And I put that URL in the Location bar, I want "it ran" to pop up as an alert.
I'm skeptical that this is possible but I'm hoping-against-hope that there is a header or a MIME type or something like that that I can set and miraculously make this happen.
This is not possible. The browser has no idea what context the JavaScript should run in; for example, what are the properties of window? If you assume it can come up with some random defaults, what about the behavior of document? If someone does document.body.innerHTML = "foo" what should happen?
JavaScript, unlike images or HTML pages, is dependent on a context in which it runs. That context could be a HTML page, or it could be a Node server environment, or it could even be Windows Scripting Host. But if you just navigate to a URL, the browser has no idea what context it should run the script in.
As a workaround, perhaps use about:blank as a host page. Then you can insert the script into the document, giving it the appropriate execution context, by pasting the following in your URL bar:
javascript:(function () { var el = document.createElement("script"); el.src = "PUT_URL_HERE"; document.body.appendChild(el); })();
Or you can use RunJS: https://github.com/Dharmoslap/RunJS
Then you will be able to run .js files just with drag&drop.
Not directly, but you could make a simple server-side script, e.g. in PHP. Instead of
http://example.com/file.js
, navigate to:
http://localhost/execute_script.php?url=http://example.com/file.js
Of course, you could smallen this by using RewriteRule in Apache, and/or adding another entry in your hosts file that redirects to 127.0.0.1.
Note that this is not great in terms of security, but if you use it yourself and know what you're downloading, you should be fine.
<html>
<head>
<script>
<? echo file_get_contents($_GET['url']); ?>
</script>
</head>
<body>
</body>
</html>
In the address bar, you simply write
javascript:/some javascript code here/;void(0);
http://www.javascriptkata.com/2007/05/01/execute-javascript-code-directly-in-your-browser/
Use Node.js.
Download and install node.js and create a http/s server and write down what you want to display in browser.
use localhost::portNumber on server as url to run your file.
refer to node js doc - https://nodejs.org/dist/latest-v7.x/docs/api/http.html
Run - http://localhost:3000
sample code below :
var http = require("http");
var server = http.createServer(function(req,res){
res.writeHead(200,{'Content-Type':'text/html'});
res.end("hello user");
}); server.listen(3000);`
you can write your own browser using qt /webkit and do that.
when user enters a js file in url location you can read that file and execute the javascript .
http://code.google.com/apis/v8/get_started.html is another channel.
not sure if it meets ur need.

External Javascript File - QueryString Info Available?

On an HTML page I have a reference to an external Javascript file like this:
<script src="http://MyServer.com/js/myscript.js?Happy=True"></script>
Inside the myscript.js when it runs, can I get the Happy=True QueryString-like part of the js source URL?
Note I do not want the URL of the HTML page, I need to get the URL of the js file.
My Guess is no.
You will be able to detect the src-attribute of the script-element(would be easier to locate if the <script> has an ID). Out of that URL you could extract the Query-String.

URL Hash modification after document.write()

I download via jQuery AJAX a whole html webpage. I want to replace the content of the current page with the one downloaded via ajax. I do it with document.write(). It doesn't work correctly because whenever I try to modify the hash, the webpage is reloaded.
I know in IE it it necessary an iframe, but that is not the problem, because I use jQuery History plugin. The problem is due to the use of document.write(), but I don't know why.
Update:
index.php -> main entry point, which downloads JS code to parse URL after hash and invoke request.php.
request.php -> request entry point. It returns the webpage.
It works OK when I simulate a direct request to request.php and the downloaded webpage updates the hash.
It doesn't work (in FFox only) when I simulate a original request to index.php, which downloads the webpage via request.php and the downloaded page modifies the hash.
I use document.write() to write the content of the webpage to the current window. So the problem is about the modification of the hash in a document "being written".
don't use document.write().
instead use $('your selector').html(your_html_fetched_via_ajax);
I thinkg that you can't modify the whole html object because it means erasing the reference to the javascript script tag. I would say your best bet is to either just link to the request.php page or just change the body tag
$('body').html(response_html);
And I agree with harshath.jr, don't use document.write().
The individuals pointing you towards an iframe are correct. Add the iframe, and simply set the src attribute to the page you're fetching...you won't even need request.php.
If you really want to try to load in the html without an iframe, you'd have the parse out the elements in the head and add them to your documents , and also parse the contents of the and add them to the current pages body. Its not guaranteed to display correctly, though. I think an iframe is really what you're looking for.

Follow a URL using JavaScript

Is there any way to follow a URL in JavaScript without setting the document.location.href?
I have a page that displays a list of objects and each object may have a file download associated with it, which is accessed via a hyperlink. Clicking the link initiates an AJAX request that ultimately leads to a transient file being generated that can be referenced by a unique and temporary URL.
At the moment when the AJAX call completes, it simply sets the document.location.href to the temporary URL and the file download is initiated. Of course this has the side effect of changing the URL in the browser's address bar, so if the page is refreshed the file is downloaded again rather than the object listing page itself getting refreshed. I guess I could set the URL back to what it was before, but that feels a bit hacky.
Incidentally, I'm using the Prototype JavaScript framework.
you could open a new window with the new url? or try setting an iframe's url to the new url, both should present a file download (the latter being the better option)
You could use a hidden iframe - set the src of that to the file to download.
If you're doing all this just to trigger a file download, it sounds like a good application for using a hidden Iframe. Set the SRC of the Iframe instead, so you don't have to mess with the main page.

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