So I'm playing a game online on my laptop and it is a pretty simple html5 game but the optimization is nonexistant. The game with a few circles on my screen is using 85% of my cpu.
Logically, I started profiling the game and was trying to figure out if I could optimize it for my laptop. Now, what I'm wondering is how could I run the game but with a tweaked version of the JS script that is running.
If I try to save the page and run it from my laptop it of course has CORS issues so I can not access the server.
Can I somehow change the script a bit which is executing in my browser but while still staying "inside the webpage" which is running so that I may normally make XHR requests to the server?
Also, although this is not in the title of the question, can I somehow proxy the XHR request to my script but while not breaking the CORS rule?
Why is it so different if I run the same thing from my browser and from a saved HTML on my desktop? I have the same IP and am doing the same thing but from the url it "feels like" I'm running it from somewhere else. Can I somehow imitate that I'm running "from the webpage" but instead run it from a modified saved html?
You could proxy, given there isn't a cross domain protection mechanism or some sort of logging in (which complicates stuff).
What you could very well do is use a browser extension which allows you to add CSS, HTML and JavaScript.
I'm not entirely savvy on extensions so I'm not sure you can modify existing code but I'm guessing that if you can add arbitrary JS code you may very well replace the script tag containing the game for a similar personally modified script based on it. It's worth a try...
Link to getting started with chrome extensions
Update:
If you're set on doing it, proxying ammounts to requesting an URL with your application and do something with the page (html) instead of the original source. I assume you want to change the page and serve it to your browser.
With this in mind you will need the following, I dont know C# so you'll have to google around for libraries and utilities:
a way to request URLs (see link at bottom)
a way to modify the page, you need a DOM crawler
a way to start said process and serve it to your browser by hitting your own URL, meaning you need some sort of web server
I found the following question specifically on proxying with C#
Related
Apologies if this is a roundabout way of asking this question, but I am a little confused about how the web and javascript work.
What I want to do: execute javascript on all pages of a list of urls I have found. (Specifically use jquery to pull info from them)
Problem I can't execute Javascript on these pages because they aren't mine and don't have the Access-Control-Allow-Origin header. So I can't load them (with AJAX) in order to use JQuery on them.
BUT Google Chrome can both load pages and execute javascript on them (with their developer's console). So if I wanted too, I could go to each page, open the developers console, and pull the information from there. If there's nothing stopping Chrome from accessing these, then why am I stopped? And, is there a way around this?
Thank you, and I hope my description makes sense. I've been researching this for a while but have found nothing that explains how seemingly inconsistent CORS is.
I could go to each page, open the developers console, and pull the information from there. If there's nothing stopping Chrome from accessing these, then why am I stopped?
You're not stopped. You, the human at the keyboard, can do exactly as you say, by visiting each page as a top-level page.
What is stopped -- happily -- is any and all scripts on the Web you happen to run having the same level of visibility that you do. Based on your cookies and your network topology, you have a unique view into the Web. You can see your home router's control interface (on 192.168.1.1 or similar). You can see any local web server you're running on 127.0.0.1. No one else can see these. If the same-origin policy were not in place, then any script that you loaded on the Web could inspect these.
And, is there a way around this?
If you have some scripts that you trust absolutely (hopefully a significant subset of "all scripts that exist on the Web") that you want to be able to bypass the same-origin policy and see your full, cross-domain view of the Web, you could load them as an extension, which can act with elevated permissions beyond the abilities of normal web pages. (See How does Same Origin Policy apply to browser extensions?)
I'm going to assume that you are looking to grab data from these pages that aren't yours and store it somewhere. I have done this before with curl using php. If you are looking to display these sites for users to interact in a different way, but starting from a page that is yours, you may be able to render these pages by grabbing the source html using curl and rendering it as a sort of proxy.
I've used this tutorial for something similar https://www.youtube.com/watch?v=_kQN-3aNCeI . Hopefully this gives you a start. I think you should be a little more detailed in your question though to get more help.
I wrote code for dropdown Menu and want to insert that code in other html files.
DropDown Menu code.
http://jsfiddle.net/techspartan/49Bpb/
For inserting the above HTML code into other HTML files I am using this code:
<html>
<head>
<script src="jquery-2.0.3.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$('#topdiv').load('index.html');
});
</script>
</head>
<body>
<div id="topdiv">
</div>
</body>
</html>
Basically I want to declare my DropDownMenu code at one location so that if I make changes in menu code than I don't have to edit every HTML file that has the DropDown.
The above code is working in Firefox but nothing is shown in Chrome and IE-10.
Are you working locally on your machine, without any webserver? Chrome does not allow loading files via AJAX from your file system (see bugreport).
You may use XAMPP or something similar to serve your files via a local webserver.
If you are on Windows, XAMPP is probably the easiest way to get your local webserver up and running: http://www.apachefriends.org/en/xampp.html
On Mac, you may also use MAMP http://www.mamp.info/en/index.html
You may also force Chrome to allow local file access on Windows if you are starting it with --allow-file-access-from-files, more information in this stackoverflow question
For what it's worth, I have code that uses jQuery().load() to inject content into a page, and it work just fine.
If this is static content that is meant to be a standard part of your page, then the other answers/comments saying to do it on the server are probably right; stuff like that is generally better to be included on the server, because it will make your site perform a lot better than doing it on page load via Javascript. (in fact, loading a static menu this way is likely to give your site a noticable performance problem when users load the page; be warned!).
However in general the technique of dynamically adding content to a page using Javascript is perfectly valid, and commonly used, so I'll answer the question based on that.
There's nothing that I can see that's specifically wrong with the minimal example you provided, except for a missing Doctype, so I'm going to guess that's probably your issue:
If you don't have a doctype, the browser will render the page in Quirks mode. And jQuery is not designed to work in quirks mode.
Solution: Add the following line to the top of your code and try it again:
<!DOCTYPE html>
You may also want to check that IE isn't showing your page in compatibility mode as well, because that might also cause problems. If it is, you could also add an X-UA-Compatible meta tag to your page's <head> section to force IE into standards mode:
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
Finally, if you need to support IE8 or earlier, you should switch from jQuery v2 back to the latest release of jQuery v1 (currently 1.10.2), as jQuery v2 does not work with IE8 and earlier.
Hope that helps.
The issue you are having is not due to anything wrong with your code, but with security policies of modern browsers. Here's what happens on your development machine:
Your browser loads your local HTML file.
Your browser executes the javascript, which tries to access a file on your machine.
Your browser says, "NO!" Because this is a huge security error - without this policy websites could read through every file on your hard drive or silently send copies of any of your private information to their servers, just because you visited a site with javascript enabled. BAD!
There are some ways to try to tell your browser "No, it's ok, I want to allow this..."...but you know, this has become exceedingly difficult as it often silently breaks with new browser versions. I've slammed my head against the wall way too often, so I might suggest you skip trying to make your browser OK with what you are trying to do.
Now, why does this work on a live site? Here's what happens.
Your browser loads a website.
Your browser executes the javascript.
The script asks for a file to be loaded/accessed from a website.
Your browser says..."well, we're already on this website, so sure! Load all the files you want from that web server!" And your browser kindly gets the file, and returns it to your script, where you can painlessly include the HTML to your hearts content.
To make this work on your development machine, you have ultimately 3 choices:
1) Upload the files to a web server, then do your testing there.
2) Make your own "localhost" web server. You then access your site with something like localhost/index.html - etc. This is just enough to prevent the browser from shutting down your file load requests, because you are requesting an HTTP operation, note a FILE operation.
3) Try to force your browser to allow these requests. Details vary by browser, some browsers won't let you do this at all, and I've given up on doing this myself.
The hidden 4th choice is using HTML5 File System features, but with such poor support for technology I suggest you not even try it - the bug you are facing is purely with your development machine, so changing the technology you are using purely for a minor development convenience seems silly.
Severin provides links to the excellent XAMPP and MAMP software packages, which are the easiest way of getting yourself a good development localhost server.
We have a node.js app that displays content on partner websites. Our partners include some javascript code in their HTML templates, pointing to our server, and we then use the URL of the page which loads our code to figure out what content to show. Being a third-party script, we mostly rely on document.referrer to get the URL of the including page, but sometimes we are included in an iframe, which complicates things. We are looking to make this code more robust by writing a comprehensive test suite.
Is there a good way to test this type of functionality on the server? We’d need to emulate a browser with javascript support, and it would need to report the referrer like a normal browser would. We’d also need to be able to test cross-origin issues on the server, by simulating domain names, ports etc.
It would be preferable to use node.js for this, but that’s not a requirement.
This has been asked a lot of times already: I need to get the full file path via a web-page. The use case is an application running on the same machine as the browser (i.e. the application starts a local HTTP server and fires up the browser.) File-paths are of course valid and the same for both client/server now. The use case it that the user selects a file and then the server process does some computation on it, and the input files are typically large (read: several GiB in size.)
The easiest thing would be to directly access the path using , but for security reasons, this is disabled. I'm looking now for the least intrusive workaround to this problem. The target browser in question is Chrome. I'm fine if the user has to click "accept" once on some security warning, as long as I can ensure that it won't appear again.
Do I have to write an extension, NSPlugin, can I use some special header magic to mark my page as "local", is there some security setting I can set? The less the client has to do the better, and I would prefer some "click here to allow access ..." solution above everything else. Can I directly install an extension from the server process that would do this (after the user clicks accept?)
Is it possible to do this with a Java applet/Flash? That would be the easiest solution, and clients are guaranteed to have Flash installed (as it is bundled in Chrome...)
You can create Java applet for tasks like this and self-sign it. User will have to allow it to run, but then you will be able to access applet's function that will return file path string via Javascript.
Clearly file io on the client's system is forbidden from JavaScript. If this wasn't the case it would be absolutely trivial to hack every web browser that visits your website.
Battlefiled 3 is controlled though the browser. To do this EA wrote a browser extension for the top three browsers. But that's resource intensive. If you just care about chrome you can use an addon, and for that i suggest using the NPAPI.
And as MOleYArd said, Java is a good solution and probably more common than an extension or addon.
I need to build a small "monitoring" scraper for a 3rd party website (it's an external website that has stats about our visitors).
Unfortunately, this website is very hard to scrape through the normal "wget" mechanism, because it uses a ton of sophisticated JS, part of it generated by GWT. So my workaround was to create a GreaseMonkey script and then have this script call a PHP page that would log the scraped data. Then as soon as Firefox starts with this webpage-to-scrape, the script goes to work.
This works well, but now I am trying to make it more robust as far as monitoring tools go. I want it to run on the server using a cron job. As far as I understand such things, this requires a DISPLAY variable to be set and for an X session to exist (Firefox is refusing to run for me). Is there any nice way to allow it to run from the batchuser account as a cron job?
I've done something similar to get Selenium running headless on a server. I used Xvfb.
http://en.wikipedia.org/wiki/Xvfb
This article has some tips for using Xvfb with Firefox:
http://semicomplete.com/blog/geekery/xvfb-firefox.html
The best way to do that is to build Firefox in the headless mode: http://hg.mozilla.org/incubator/offscreen