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.
Related
I have loaded a web page and now opened Chrome developers console. Now I want to read the resource files that website has loaded (like styles / images / language properties) in the web browser console. If it is possible to read what network calls made from console using Javascript code will also suffice.
(Actual implementation would be like:
I will be launching Chrome browser using Selenium and Java code and once launched I will execute Javascript code to get internationalisation file loaded over network for particular website so that I can adapt my Java selenium code base as per internationalisation language used.
URL : https://www.sapfioritrial.com/sites?helpset=trial&sap-client=001
Trying to get url of this i18n_en.properties file which can be seen in network tab but I need to get this using Javascript executed using Java Selenium code
)
Any help highly appreciated
Go to the "Resources" tab. Under the "Frames" folder in the tree view on the left, you'll find a hierarchy of the files and clicking them lets you view the contents.
The "Network" tab lets you see all the resources accessed, and shows you the HTTP status (ie: 200, 404, 500, etc...), size, how long it took to download, and in what order the resources were loaded.
The network calls are available in the network tab
I have a program where the user does some actions (i.e. clicking on several buttons). I want to record their clicks and the buttons that they click to allow the user to then download a text file with a record of their clicks when they click a separate "download" button. I looked at the File-system APIs for HTML 5, but they seemed to not have cross-browser support. I would ideally like to have this entire file generation and download scheme be entirely client-side, but I am open to server-side ideas as well.
TL;DR: Essentially I'm looking for an equivalent to Java's FileWriter, FileReader, ObjectOutputStream, and ObjectInputStream within Vanilla JS or jQuery (would like to stay away from php, but I'll use it as a last option).
Also, why don't all browsers support the filesystem api? (I'm guessing that it would make MSWord and Pages go out of business with all the open source clientside text editors that could come out.)
Unfortunately the HTML5-File-system is no longer a part of the spec, long story short FF refused to implement because they claimed everything you could do in the File-System API was doable in the HTML5 Indexeddb (which was mostly true). Please see this blog post for more on why FF didn't implement. I do not know IE's story. (I may have exagerated why FireFox didn't implement, I'm still bummed because you cannot actually do everything in indexeddb that you can do in the noew "Chrome File-system API")
Typically if two of those three browsers implement a spec, it stays in the spec. Otherwise that spec gets orphaned. However, I'm fairly certain a large reason the file-system api didn't take off is because of the IndexedDB API (caniuse IndexedDB) really took off when both specs were introduced. If you want cross browser support, check this api out.
That all said if you are still set on the file-system api some developers wrote a nice wrapper around the IndexedDB, the File-system api wouldn't actually supply you with a stream anyway. You would have to keep appending events to a given file given a fileWriter object. you'd then have to read the entire file and send to the server via an ajax request and then downloaded from the server once successfully uploaded.
The better route would be to use the IndexedDB apiwhich as stated on developer.mozilla
Open a database.
Create an object store in upgrading database.
Start a transaction and make a request to do some database operation, like adding or retrieving data.
Wait for the operation to complete by listening to the right kind of DOM event.
Do something
with the results (which can be found on the request object).
Here are a couple tutorials on the IndexedDB.
https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API/Using_IndexedDB
http://www.html5rocks.com/en/tutorials/indexeddb/todo/
As for giving the user that file, as mentioned briefly before you would have to upload the file to the server and download upon the "download" request. Unfortunately you have to trick the user into giving them the data already on their machine. Anyway, hope this all helps.
This doesn't involve coding. I am just curious on how to make a page like the one described below.
I came across a website where we can attend quiz/tests.
I tried to debug the browser so that I can see if I could hack through the codes by getting the values that are getting passed in debugger.
But to my surprise the debugger is not coming up when I click F12 in that page.
Somehow I opened debugger for that page and I clicked on the Network tab to capture requests that are sent.
But as I was proceeding through the test, not even one request is getting captured in the debugger but the answers are getting validated and scores are getting updated !! I was not even able to do inspect element
I guess its a java applet as i saw the below line in the the launch button
flagPlayerCourse = true;launchApplet(secureSessionId,courseName, courseType,winParams, use508);disablePlayButton(1, 0);
the url had SinglePassUserCmd.cfm?sessionid=3xxxxx
So my question is how can we create such a webpage in which the requests are not captured in the debugger!? I would be happy if someone could tell me how do the same in asp.net. In which language can we develop such web pages!?
Applets are completely different world. Its almost as good as running a .net application on your client machine.
What you see in the debugger are ajax requests and resources loading. If a site doesn't make them, you won't see any network requests in the browser.
That doesn't mean that you can't capture the data being send. You can always use a debugging proxy like fiddler to see what traffic is going across. Ofcourse a secure site would secure their traffic over https.
Applets require a java plugin in your browser. There are similar plugins like Silverlight, flash/shockwave(swf) that too can make network requests.
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.
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.