how can inject script in node-webkit when visit other url - javascript

I'm working with node-webkit. I want to do something when node-webkit visits some specific URL, but I don't know how to execute a script when node-webkit visits the other URL.
For example http://www.google.com. I can only execute native scripts, but how can I execute a script when I visit another URL like a chrome plugin?
<script type="text/javascript" src="">
document.getElementById('id').click();
</script>
Script like this can only execute when visit my native script. How can I get it to execute when visiting http://www.google.com?

You can always know what the current url is: window.location
For your specific example it seems you misunderstood the point of node-webkit. Nw does not use http protocol; it does use file protocol. You do not navigate from one external web page to another external web page as your application is local (desktop).
Be more specific if you want additional help.

It's better not to include or write scripts directly in the HTML. The disadvantage of this technique is that the script (from which you might want to do some background tasks) will reload (or vanish) every time you reload (or navigate to another page).
'node-main' in package.json is what you need. Here:
https://github.com/rogerwang/node-webkit/wiki/node-main. The scripts stays there even if you visit another page.

Related

How do I automate opening and downloading a webpage?

There is a website that has an HTML <video> element in it when loaded, however this element isn't present if I just download it with wget, so I guess it gets loaded by a script that's only ran when the page is opened in a browser. I need the video's direct link, in an automated fashion.
Could you please tell me if I have the right idea, and if there is a possible solution? Could I for example run a browser from the command line, let it load the page and all of the referenced content, then save the .html file?
You could use headless Chrome, potentially with Puppeteer scripting for that.
Though, depending on the details, there may be easier options that would get you what you need. It sounds like you're currently trying to scrape a third party website using wget. Instead of, or in addition to, requesting the .html content with wget, you could request the relevant javascript file and then extract the video url from there.

Detect if GWT *.nocache.js file loaded properly

In Javascript, what is the preferred way to validate if a GWT *.nocache.js file has loaded properly?
Background
My GWT application loads an *.nocache.js file within a simple shell .html page.
If a user visits the page with a stale auth cookie, the .html file loads perfectly from browser cache, but the *.nocache.js file fails to load, because the user needs a fresh auth token.
Since the .js file fails to load, it fails silently. The user sees a blank .html page with no indication that they need to refresh the page.
(note the particular failure here is that the .js file does not load due to wrong mime type. The auth layer handles stale auth cookies by redirecting to the login page. This page is a text/html document so the browser rejects loading it in a tag. Assume for this question that I cannot change this behavior in the application :)
What's the best way to detect this circumstance and, for example, force a refresh of the page.
Note a hard refresh will force a fetch of the .html page from the server, which will be redirect to the login.
One approach would be to tell the browser to not cache the .html file, but I'd prefer another solution that lets the .html file be cached.
Given that you cannot change things in your application, I will answer just to your question.
You need some javascript in your page.html in order to check whether the gwt script has been loaded after a fixed time:
<head>
<script>
setTimeout(function() {
if (!document.getElementById("my_module_name")) {
window.location.reload();
}
}, 4000)
</script>
<script language="javascript" src="my_module_name.nocache.js"></script>
</head>
In the case you use an iframe based linker (standard, xsiframe), the .nocache.js creates an iframe to load the appropriate permutation, and gives it the name of the module, so checking for the presence of that element after a while is enough to know whether the app was loaded.
You could also check for the presence of especial properties which gwt sets to the window like window.__gwt_activeModules
Typically, a GWT app loads first, then you do authentication. You can use a split point, if you want, to load only the login page. Then, after the authentication is confirmed, you load the other parts of your app.
I have never seen a scenario where authentication is done before a page loads. Maybe you can explain why you did it this way.
As for your question, you need a JavaScript to detect if another JavaScript was successfully loaded, but this solution adds an unnecessary level of complexity.

Block JS from loading on certain domains

I have a web service that works through giving users javascript to embed in their code. Users can also place that code on other sites to make it work there. However I also need to allow users to create a blacklist of sites that the JS should not function on. For example, a competitor or an inappropriate site.
Is there a way to check where our JS files are being loaded from, and block loading or break functionality on a per account basis?
Edit: The javascript loads an iframe on the site, so another solution would be to somehow block certain domains from loading an iframe from our server, or serve different content to that iframe
Edit 2: We're also trying to avoid doing this from with the JS because it could be downloaded and modified to get pass the block
Inspecting the url of the page
Yes, the javascript file, when it starts executing, can inspect window.url and see if the url of the main document is ok.
To see where the script was loaded from
It can also go through the dom, looking for the script node which brought in the javascript file itself and see from where the JS was loaded.
However
Anyone can load the javascript into a text editor, then change it to eliminate the tests, then host the modified JS on their own server. Obfuscating or minimizing the JS can slow someone down but obscurity is not security.
One thing you could do is have the javascript load another javascript file. That you serve from the server at a given url. The trick here is that that url will not go to a file but to a server end point that will return a javascript file. The you have that endpoint check for the routes for that user and decide if it will return the javascript you want to work or an error javascript of some kind.
This blog shows how to do it in php.dynamic-javascript-with-php

How to change content after page is loaded (JS)?

I would like a javascript to run after a page is loaded , like on the example below with a delay of 6seconds. Right after the page loads the rest of JS is lost (obvious)...
Got any ideea how change content after page is loaded without clicking a button?
javascript:window.location = "http://example.com";
setTimeout(function() {
document.getElementById('lightbox').style.display = 'none';
}, 6000);
Once you set window.location the original page will be unloaded before the new page is loaded by the browser. This means your script will be gone before the new page start loading and thus can't modify the new HTML anymore.
This behavior is inherent to the security model of the browser. Without it you could inject any JavaScript into any web site of your choosing, which would be a huge security risk. What you are asking for is so-called XSS (for cross site scripting), which is prevented by the browser applying a so-called SOP (for same-original policy).
There are some common ways to work around this limitation in a safe way:
Set up a proxy to serve both your JavaScript and the original site. This way both your script and the original site come from the same domain and satisfy the browser's same-original policy (SOP). You could run the original site in an iframe with your custom script occupying the top-level window. Alternatively you could inject your script into the HTML as it is being retrieved through your proxy.
Run your script as a browser add-on or user-script. If you choose to do this, the user will have to specifically grant your script the rights to run locally with elevated rights. Greasemonkey popularized client-side scripts for Firefox a few years ago, but recently they seem to have lost momentum.
Ask the site owner to include your script. I doubt this is a valid option for your situation. But if it is a valid option it is definitely the simplest one.
Ask the user to run your script after the site has loaded. This one is probably also not valid for you, but if valid it would once again be a very simple solution.
Your example shows that you are first redirecting and then attempting to hide #lightbox. This script would not work, because you are redirecting the browser to another site before #lightbox gets hidden.
In short, you cannot have Javascript of a previous page manipulate DOM of the next page if you redirect the user to another URL (or even the same URL). Only Javascript that is 'on currently open page' can manipulate currently open page and no other pages.
I have not understood what you are saying. JS is lost? Please be more clear.
I think what you are talking about is the jquery ready function which runs after the DOM is ready. Or in the other case, try using window.onload() function.
This should do the job:
$(window).bind('load', function() {
// your code here
});
Then simply add the delay to your added code with .delay("6000");
The inserted code will only run when your page is completely loaded.

How can I test JavaScript without placing it on the website?

I'm talking about something like GreaseMonkey but that would accept the script just as it would be on the website. Adding external scripts to Greasemonkey has been a pain for me so far.
So, I have a client who wanted me to write a specific script for him. Because the script reads the URL of the page visited by a user I can only test it on the website but i don't have access to the source code of the website. I'd like to make sure I deliver to the client a 100% working script so I would love to test it first.
How can I do that? Any plugins that would just allow me to copy the script and would run it every time I load a page of the website?
Obviously, if you can, you want to set up a copy of the page on which the script operates, on a local web server where you can play around with things.
If that isn't possible for whatever reason, you can inject your script directly into their site when you're looking at it with your browser using a bookmarklet. The code to do it is roughly:
var script = document.createElement('script');
script.src = "...the path to your script file, ideally on a local web server rather than a file:// path...";
document.body.appendChild(script);
Once you've tweaked the above (pretty much just supplying the src value), you can turn it into a bookmark via the Crunchinator. Once you have your bookmarket, just visit the site you're developing this for and click your bookmarklet, and your script will be added to the page (just for you, obviously, and just for that visit to the page).
Then your develop/test cycle becomes:
Modify the script file (for instance, to fix a bug)
Open their site
Click your bookmarklet to add your script file to the page
Using something like GreaseMonkey can lead to unexpected results since GM runs outside of the Browsers Sandbox and GM scripts always run after everything else has loaded.
My solution for this would probably be:
Setup a local WebServer
Use "Save page..." to get the page contents, then put them on your localhost
Now add your script to the page etc. and make it work
That gives you A) A flexible development environment and B) more "realworld" results, hell you can even edit you hosts file to use the same URL that your client's page has (of course you need to re-edit the file if you want to visit the original page) and C) you can test in IE etc. too.

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