I have seen this excellent firefox extension, Screengrab!. It takes a "picture" of the web page and copies it to the clipboard or saves it to a png file. I need to do so, but with a new web page, from an url I have in javascript. I can open the web page in a new window, but then I have to call the extension -not to press the control- and saves the page once the page is fully loaded.
Is it possible?
I am pretty certain that it is not possible to access any Firefox add-on through web page content. This could create privacy and/or security issues within the Firefox browser (as the user has never given you permission to access such content on their machine). For this reason, I believe Firefox add-ons run in an entirely different JavaScript context, thereby making this entirely impossible.
However, as Dmitriy's answer states, there are server-side workarounds that can be performed.
Does not look like ScreenGrab has any javascript API.
There is a PHP solution for Saving Web Page as Image.
If you need to do it from JavaScript (from client side) - you can:
Step 1: Create a PHP server app that does the trick (see the link), and that accepts JSONP call.
Step 2: Create a client side page (JavaScript) that will send a JSONP request to that PHP script. See my answer here, that will help you to create such request.
Related
in the context you access a website, the browser dowload all required files (static files : CSS, scripts) or via AJAX. OK. You can see the dowload process in realtime using the Network tab in your devtools browser.
My question is : is it possible to "listen" to a file being dowloaded using JavaScript as the browser does in the Network tab ?
A concrete example would be to show the user what the browser is being dowloaded in from my website.
While searching over the Internet, I'v seen it's possible to overload xhr native functions : Add a "hook" to all AJAX requests on a page
Nevertheless, I don't think images and CSS download will trigger xhr function because the browser processes in it's own way.
I'm keen to hear the community about it.
Thanks in advance !
If you are explicitly downloading resources in your JavaScript code, you can inject hooks to track the AJAX requests, as per your message above. You can alternatively use the Resource Timing API to track network timing information of your requests, which is nice.
However, it is not possible to see the Network information of resources out of your control, as it requires access to the browser engine.
It is possible to get such information using a Chrome Extension, as an API exists that opens you up to this information. See chrome.devtools.network.
Well met!
I am working on a project similar to the Windows 8 tile-interface, only for Websites.
The idea is that, when a tile is clicked, it grows to fill the site (leaving a menu-bar on the top free) and the user can reguarly browse the loaded site. When he clicks a button on the menu-bar, the tile grows back.
My approach was to use IFrames. But those can be disabled through a HTTP-option by the visited site, or by using some javascript to test window toplevel.
Therefore I need some kind of alternative to IFrames. The best thing I was able to find was the JQuery .load(url), which only displays the content of the site, not making it regulary useable. It was very slow in my tests, too.
Is there something I can use, or do I have to drop the idea?
Thanks in advance!
Loading resources from different origins is very limited on the client side. Your best bet is probably a proxy on the server side (which isn't a perfect solution as it's used by scammers, read about it carefully) - I remember this iPad simulator has a fake Mobile Safari browser which uses php simple proxy.
Using Client Side Technology ...
jQuery's .load() will fetch the resource using AJAX and is constrained by the same-domain origin policy (security sandbox) that is inherent to the XMLHttpRequest object.
an iFrame will load the resource but as you pointed out it has drawbacks.
Using Server Side Technology ...
if you have only a few websites in the tiles that will need to be opened, you could preload them using a server side technology (php, jsp, asp) and hide them in a container object (like a div element) and then programmatically show them when the user activates the tile though a hover or click event.
Using java for example, you could use the java.net library to open a string buffer, read and save the contents of the website, and then add the variable to the servlet response. Using JSTL you would output the variable from the response object.
There's this website which has a javascript method in it that downloads a file. To call this method you have to set what language and serial number you're looking for and when that's done, the file is being generated according to the specified information you've just stated and then the file is being downloaded. Does anyone know how to specify this information, then send it and then download the file without going to this website?
Thanks in advance, Steve-O
If you use any tool that shows you what actual networking happens, you can discover the specific web requests that downloads the file. Chrome has those tools built in. The Firebug add-on adds those tools into Firefox. There are also apps that record all networking to/from the browser such as Fiddler which can be used to sleuth on the networking being done.
Of course, there may also be some authentication going on (a log-in, some cookies, etc...) that might be required, but all of that is visible with the right developer tools. Once you see exactly what is being sent over the wire, it's usually not hard to send that same request without a browser or without visiting that web page. If login credentials are required, that will still be required, but even that can be provided without a browser (e.g. from a server-side script).
JavaScript, as of the moment, can't download files. So how files gets downloaded? Well, the developer redirects the browser to a URL using
location.href = 'http://site.com/download.zip';
When the browser is redirected to this URL, it can't open the file, so it downloads it.
You need to determine that URL the browser redirects to. There are many ways to do that. One that comes to mind is the Fiddler app that records each HTTP request and thus can give you the URL.
My guess, however, is that the URL is generated on the fly. You need to study the JavaScript in this case and see the required mechanism to make the server generates the URL.
Can Javascript cause browsers generally (and Chrome for Mac in particular) to invoke an external helper application for a URI without opening a new tab/window, or navigating away from the current page?
The context is that I am developing an extension for Chrome that occasionally needs to invoke particular actions outside of the browser. Using the rather neat trick described here, the extension only need open particular URIs to invoke suitable AppleScript.
However, how should one open such URIs from a script running in an extension's background page? I don't think XMLHttpRequest will help, as Chrome won't (shouldn't?) attempt to use an external helper application for XHR; nor does it appear that setting window.location.href has any effect on such a background page (it is not a problem if the background page is unloaded).
My current solution is to open a new window, but it's unnecessary and rather distracting for the user.
There are a few options here:
You could write an NPAPI plugin.
You can use a WebSocket client in the browser, and run a local server on your desktop. That way you establish a tunnel to your local machine to do pretty much anything you want there.
I did this for relaying global media key presses to control web-based music players and wrote it up. Source here.
I just realised I can do this with an <iframe/> in the background page. Très simple!
I apologize if this has been asked before. I searched but did not find anything. It is a well-known limitation of AJAX requests (such as jQuery $.get) that they have to be within the same domain for security reasons. And it is a well-known workaround for this problem to use iframes to pull down some arbitrary HTML from another website and then you can inspect the contents of this HTML using javascript which communicates between the iframe and the parent page.
However, this doesn't work on the iPhone. In some tests I have found that iframes in the Safari iPhone browser only show content if it is content from the same site. Otherwise, they show a blank content area.
Is there any way around this? Are there other alternatives to using iframes that would allow me to pull the HTML from a different domain's page into javascript on my page?
Edit:
One answer mentioned JSONP. This doesn't help me because from what I understand JSONP requires support on the server I'm requesting data from, which isn't the case.
That same answer mentioned creating a proxy script on my server and loading data through there. Unfortunately this also doesn't work in my case. The site I'm trying to request data from requires user login. And I don't want my server to have to know the user's credentials. I was hoping to use something client-side so that my app wouldn't have to know the user's credentials at the other site.
I'm prepared to accept that there is no way to accomplish what I want to do on the iPhone. I just wanted to confirm it.
You generally can NOT inspect the contents of an iframe from another domain via JavaScript. The most common answers are to use JSONP or have your original server host a proxy script to retrieve the inner contents for you.
Given your revisions, without modification or support from the secondary site, you are definitely not going to be able to do what you want via the iPhone's browser.
"In some tests I have found that iframes in the Safari iPhone browser only show content if it is content from the same site"
I found the same thing. Is this documented somewhere? Is there a workaround? This sounds like broken web standards to me, and I am wondering if there is a solution.