Selector that confirms image loaded using Selenium Python API - javascript

I am looking for a way to confirm the image has actually loaded. Maybe JavaScript is an option? I am using right now WebdriverWait to simply force the wait on all images, then the actual src, then I finally run my tests after...
wait = WebDriverWait(driver, 10)
...
albums = wait.until(EC.presence_of_all_elements_located((By.CSS_SELECTOR, ".albums .album img")))
albumslength = len(albums)-1
while albumslength > 0:
wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, ('.album:nth-child('+str(albumslength)+') img[src*="album-foo"]'))))
albumslength -= 1
...
This will at some point confirm "album-foo" exists in the <img src="http://www.album-foo/images/blah.jpg" of each album in albums. But it does not confirm that the image completed loading into view. I have searched high and low, anyone have a solution?
I am testing on Chrome and Firefox, so no phantom or IE restrictions, if the ideas grow into including JavaScript or related ideas that might have environment restrictions.

I am not that experienced with selenium, though I will give this a try.
If you want to check whether an image is loaded, I'd say use a boolean. Set the original value of this boolean let's say 'loaded' to false.
Then just call something like this, making sure it returns true the moment the image has loaded.
Boolean loaded = false;
WebDriver driver = new AnyDriverYouWant();
JavascriptExecutor js;
if (driver instanceof JavascriptExecutor) {
js = (JavascriptExecutor)driver;
}
loaded = (Boolean)js.executeScript("image.onload(function() { return true; });");

Related

Selenium : How to check whether second tab is loaded completly

We are using selenium for automation. We need to launch 2 URLs simultaneously.
I am using driver.get to load first URL , which has in-built synchronization for page load. To load second window , I am using code below -
String jscript="window.open('"+strURL+"')";
js.executeScript(jscript);
It works fine on chrome but on Edge , page takes time to load and when I try to do switchwindow to another window using title , it does not find window with that title.
if I add wait , then window loads and switchwindow works perfectly.
I don't want to use hardcoded wait .How I can check whether 2nd window is loaded completly?
I tried below , but it gives permission error on Edge-
String jscript="var win=window.open('"+strURL+"');win.onload=function(){}";
js.executeScript(jscript);
Try this to check whether page is loaded or not properly.
wait.until( new Predicate<WebDriver>() {
public boolean apply(WebDriver driver) {
return ((JavascriptExecutor)driver).executeScript("return document.readyState").equals("complete");
}
}
);
Hope it will help.

Selenium with headless chrome

I have testing environment which is perfectly working with chrome driver in desktop mode. I am using some javascript injections (everything works) f.e.:
public static void ForceFillInput(this Driver driver, string selector, string value)
{
var javaScriptExecutor = (IJavaScriptExecutor)driver.webDriver;
javaScriptExecutor.ExecuteScript($"$(\"{selector}\").val(\"{value}\")");
}
but when i want to run it in headless mode
AddArguments("--headless")
it will just fail on
"$ is not defined"
Can somebody help me how to inject js/jquery into headless solution?
M.
your Javascript snippet used jQuery api. In modern web development, we put Javascript at the end of HTML page to let browser to load javascript at last, so that static resources (like picture/image/text content) can display earlier as possible, withing this way to improve user experience when user open website.
I think your page also put jQuery at the end to load, try add some wait/sleep before ExecuteScript to wait browser complete load jQuery.
It looks like the shorthand for JQuery is not yet created at the time your script is executed.
Use a waiter to wait for JQuery and for the selector to be found:
public static void ForceFillInput(this Driver driver, string selector, string value)
{
string JS_SET_VALUE =
"var e; return !!window.$ && (e = window.$(arguments[0])).length > 0 && (e.val(arguments[1]), true);";
new WebDriverWait(driver, TimeSpan.FromSeconds(60))
.until(ctx => (bool)((IJavaScriptExecutor)ctx).ExecuteScript(JS_SET_VALUE, selector, value));
}

iframe content doesn't always load

So I have a system that essentially enabled communication between two computers, and uses a WebRTC framework to achieve this:
"The Host": This is the control computer, and clients connect to this. They control the clients window.
"The Client": The is the user on the other end. They are having their window controlled by the server.
What I mean by control, is that the host can:
change CSS on the clients open window.
control the URL of an iframe on the clients open window
There are variations on these but essentially thats the amount of control there is.
When "the client" logs in, the host sends a web address to the client. This web address will then be displayed in an iframe, as such:
$('#iframe_id').attr("src", URL);
there is also the ability to send a new web address to the client, in the form of a message. The same code is used above in order to navigate to that URL.
The problem I am having is that on, roughly 1 in 4 computers the iframe doesn't actually load. It either displays a white screen, or it shows the little "page could not be displayed" icon:
I have been unable to reliably duplicate this bug
I have not seen a clear pattern between computers that can and cannot view the iframe content.
All clients are running google chrome, most on an apple powermac. The only semi-link I have made is that windows computers seem slightly more susceptible to it, but not in a way I can reproduce. Sometimes refreshing the page works...
Are there any known bugs that could possibly cause this to happen? I have read about iframe white flashes but I am confident it isn't that issue. I am confident it isn't a problem with jQuery loading because that produces issues before this and would be easy to spot.
Thanks so much.
Alex
edit: Ok so here is the code that is collecting data from the server. Upon inspection the data being received is correct.
conn.on('data', function(data) {
var data_array = JSON.parse(data);
console.log(data_array);
// initialisation
if(data_array.type=='init' && inititated === false) {
if(data_array.duration > 0) {
set_timeleft(data_array.duration); // how long is the exam? (minutes)
} else {
$('#connection_remainingtime').html('No limits');
}
$('#content_frame').attr("src", data_array.uri); // url to navigate to
//timestarted = data_array.start.replace(/ /g,''); // start time
ob = data_array.ob; // is it open book? Doesnt do anything really... why use it if it isnt open book?
snd = data_array.snd; // is sound allowed?
inititated = true;
}
}
It is definitele trying to make the iframe navigate somewhere as when the client launches the iframe changes - its trying to load something but failing.
EDIT: Update on this issue: It does actually work, just not with google forms. And again it isn't everybody's computers, it is only a few people. If they navigate elsewhere (http://www.bit-tech.net for example) then it works just fine.
** FURTHER UPDATE **: It seems on the ones that fail, there is an 'X-Frames-Origin' issue, in that its set the 'SAMEORIGIN'. I dont understand why some students would get this problem and some wouldn't... surely it depends upon the page you are navigating to, and if one person can get it all should be able to?
So the problem here was that the students were trying to load this behind a proxy server which has an issue with cookies. Although the site does not use cookies, the proxy does, and when the student had blocked "third party cookies" in their settings then the proxy was not allowing the site to load.
Simply allowed cookies and it worked :)
iframes are one of the last things to load in the DOM, so wrap your iframe dependent code in this:
document.getElementById('content_frame').onload = function() {...}
If that doesn't work then it's the document within the iframe. If you own the page inside the iframe then you have options. If not...setTimeout? Or window.onload...?
SNIPPET
conn.on('data', function(data) {
var data_array = JSON.parse(data);
console.log(data_array);
// initialisation
if (data_array.type == 'init' && inititated === false) {
if (data_array.duration > 0) {
set_timeleft(data_array.duration); // how long is the exam? (minutes)
} else {
$('#connection_remainingtime').html('No limits');
}
document.getElementById('content_frame').onload = function() {
$('#content_frame').attr("src", data_array.uri); // url to navigate to
//timestarted = data_array.start.replace(/ /g,''); // start time
ob = data_array.ob; // is it open book? Doesnt do anything really... why use it if it isnt open book?
snd = data_array.snd; // is sound allowed?
inititated = true;
}
}
}

script to extract information from a webpage in a browser

Background
I have a network performance testing tool which after every test,displays all its results in a new results page. Below is my workflow to find the final value.(Details not relevant here but the html elements i am looking for might
1.Go to a section called "Data frame" ( which has a table with timestamp,transmit,recieve and percentage as columns) and get the time stamp when percentage first drops below 99.9
Here is a snippet of the "Data Frame" table
Data frame snippet
2.Go to another section called "Data throughput" ( table with timestamp, throughput as columns) and get the maximum value of throughput before the previously found timestamp.
After every test, i have to do this manually, but there should be someway to automate this.
Question
1.Is it possible to write a script ( maybe in javascript ) to automate my workflow for every new results page?
example algorithm
section = webpage.section_with_title("Data frames")
for each row in section
find first my_timestamp with percent < 99.9
done
section2 = webpage.section_with_title("Data Throughput")
for each row in section2
find max row.throughput if row.timestamp < my_timestamp
don
2.Once i write the script, how do i execute it in the web page?
3.Can i leverage the firefox/chrome developer console in some way ?
Note:I develop mostly in C,C++ and ruby with very basic experience in HTML and CSS. I have barely used javascript, but i have a vague idea that the browsers use it to handle the content of every page.
My thought process was to somehow execute the script through firefox console, and it will provide me with the results... is that difficult?
edit: since i am not familiar with the web development terms, ill put an a different choice of words...
1.i open up the results page
2.i open the console window of firefox/chrome
3.run my script(dont know what language).
4.i should get the result in the console. i do not want to modify the results page. i just need the result displayed to me(in the console, or to a text file).
Yes it's possible to do what you think using Javascript. Please look up XMLHttpRequest
Here is a way for you to start (in Java):
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
public class YourClass
{
private WebDriver webDriver = null;
public void open() throws Exception
{
webDriver = new FirefoxDriver();
}
public void close() throws Exception
{
webDriver.quit();
}
public void doStuff() throws Exception
{
WebElement element = webDriver.findElement(By.id(...));
...
// Alternatively, it might be easier to parse the entire
// page-source instead of searching elements in the DOM
String pageSource = webDriver.getPageSource();
...
}
}
You will need to download the following JAR files and add them in your project's class-path:
selenium-java-2.xx.0.jar (currently xx=39)
selenium-server-standalone-2.xx.0.jar (currently xx=39)

Detecting protocol handler with Javascript [duplicate]

I have created a custom URL protocol handler.
http://
mailto://
custom://
I have registered a WinForms application to respond accordingly. This all works great.
But I would like to be able to gracefully handle the case where the user doesn't have the custom URL protocol handler installed, yet.
In order to be able to do this I need to be able to detect the browser's registered protocol handlers, I would assume from JavaScript. But I have been unable to find a way to poll for the information. I am hoping to find a solution to this problem.
Thanks for any ideas you might be able to share.
This would be a very, very hacky way to do this... but would this work?
Put the link in as normal...
But attach an onclick handler to it, that sets a timer and adds an onblur handler for the window
(in theory) if the browser handles the link (application X) will load stealing the focus from the window...
If the onblur event fires, clear the timer...
Otherwise in 3-5seconds let your timeout fire... and notify the user "Hmm, looks like you don't have the Mega Uber Cool Application installed... would you like to install it now? (Ok) (Cancel)"
Far from bulletproof... but it might help?
There's no great cross-browser way to do this. In IE10+ on Win8+, a new msLaunchUri api enables you to launch a protocol, like so:
navigator.msLaunchUri('skype:123456',
function()
{
alert('success');
},
function()
{
alert('failed');
}
);
If the protocol is not installed, the failure callback will fire. Otherwise, the protocol will launch and the success callback will fire.
I discuss this topic a bit further here:
https://web.archive.org/web/20180308105244/https://blogs.msdn.microsoft.com/ieinternals/2011/07/13/understanding-protocols/
This topic is of recent (2021) interest; see https://github.com/fingerprintjs/external-protocol-flooding for discussion.
HTML5 defines Custom scheme and content handlers (to my knowledge Firefox is the only implementor so far), but unfortunately there is currently no way to check if a handler already exists—it has been proposed, but there was no follow-up. This seems like a critical feature to use custom handlers effectively and we as developers should bring attention to this issue in order to get it implemented.
There seems to be no straightforward way via javascript to detect the presence of an installed app that has registered a protocol handler.
In the iTunes model, Apple provides urls to their servers, which then provide pages that run some javascript:
http://ax.itunes.apple.com/detection/itmsCheck.js
So the iTunes installer apparently deploys plugins for the major browsers, whose presence can then be detected.
If your plugin is installed, then you can be reasonably sure that redirecting to your app-specific url will succeed.
What seams the most easy solution is to ask the user the first time.
Using a Javascript confirm dialog per example:
You need this software to be able to read this link. Did you install it ?
if yes: create a cookie to not ask next time; return false and the link applies
if false: window.location.href = '/downloadpage/'
If you have control of the program you're trying to run (the code), one way to see if the user was successful in running the application would be to:
Before trying to open the custom protocol, make an AJAX request to a server script that saves the user's intent in a database (for example, save the userid and what he wanted to do).
Try to open the program, and pass on the intent data.
Have the program make a request to the server to remove the database entry (using the intent data to find the correct row).
Make the javascript poll the server for a while to see if the database entry is gone. If the entry is gone, you'll know the user was successful in opening the application, otherwise the entry will remain (you can remove it later with cronjob).
I have not tried this method, just thought it.
I was able to finally get a cross-browser (Chrome 32, Firefox 27, IE 11, Safari 6) solution working with a combination of this and a super-simple Safari extension. Much of this solution has been mentioned in one way or another in this and this other question.
Here's the script:
function launchCustomProtocol(elem, url, callback) {
var iframe, myWindow, success = false;
if (Browser.name === "Internet Explorer") {
myWindow = window.open('', '', 'width=0,height=0');
myWindow.document.write("<iframe src='" + url + "'></iframe>");
setTimeout(function () {
try {
myWindow.location.href;
success = true;
} catch (ex) {
console.log(ex);
}
if (success) {
myWindow.setTimeout('window.close()', 100);
} else {
myWindow.close();
}
callback(success);
}, 100);
} else if (Browser.name === "Firefox") {
try {
iframe = $("<iframe />");
iframe.css({"display": "none"});
iframe.appendTo("body");
iframe[0].contentWindow.location.href = url;
success = true;
} catch (ex) {
success = false;
}
iframe.remove();
callback(success);
} else if (Browser.name === "Chrome") {
elem.css({"outline": 0});
elem.attr("tabindex", "1");
elem.focus();
elem.blur(function () {
success = true;
callback(true); // true
});
location.href = url;
setTimeout(function () {
elem.off('blur');
elem.removeAttr("tabindex");
if (!success) {
callback(false); // false
}
}, 1000);
} else if (Browser.name === "Safari") {
if (myappinstalledflag) {
location.href = url;
success = true;
} else {
success = false;
}
callback(success);
}
}
The Safari extension was easy to implement. It consisted of a single line of injection script:
myinject.js:
window.postMessage("myappinstalled", window.location.origin);
Then in the web page JavaScript, you need to first register the message event and set a flag if the message is received:
window.addEventListener('message', function (msg) {
if (msg.data === "myappinstalled") {
myappinstalledflag = true;
}
}, false);
This assumes the application which is associated with the custom protocol will manage the installation of the Safari extension.
In all cases, if the callback returns false, you know to inform the user that the application (i.e., it's custom protocol) is not installed.
You say you need to detect the browser's protocol handlers - do you really?
What if you did something like what happens when you download a file from sourceforge? Let's say you want to open myapp://something. Instead of simply creating a link to it, create a link to another HTML page accessed via HTTP. Then, on that page, say that you're attempting to open the application for them. If it doesn't work, they need to install your application, which they can do by clicking on the link you'll provide. If it does work, then you're all set.
This was a recommended approach for IE by Microsoft support
http://msdn.microsoft.com/en-us/library/ms537503%28VS.85%29.aspx#related_topics
"If you have some control over the binaries being installed on a user’s machine, checking the UA in script seems like a relevant approach:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\5.0\User Agent\Post Platform
" -- By M$ support
Every web page has access to the userAgent string and if you drop a custom post platform value, detecting this in javascript using navigator.userAgent is quite simple.
Fortunately, other major browsers like Firefox and Chrome (barring Safari :( ), do not throw "page not found" errors when a link with a custom protocol is clicked and the protocol is not installed on the users machine. IE is very unforgiving here, any trick to click in a invisible frame or trap javascript errors does not work and ends up with ugly "webpage cannot be displayed" error. The trick we use in our case is to inform users with browser specific images that clicking on the custom protocol link will open an application. And if they do not find the app opening up, they can click on an "install" page. In terms of XD this wprks way better than the ActiveX approach for IE.
For FF and Chrome, just go ahead and launch the custom protocol without any detection. Let the user tell you what he sees.
For Safari, :( no answers yet
I'm trying to do something similar and I just discovered a trick that works with Firefox. If you combine it with the trick for IE you can have one that works on both main browsers (I'm not sure if it works in Safari and I know it doesn't work in Chrome)
if (navigator.appName=="Microsoft Internet Explorer" && document.getElementById("testprotocollink").protocolLong=="Unknown Protocol") {
alert("No handler registered");
} else {
try {
window.location = "custom://stuff";
} catch(err) {
if (err.toString().search("NS_ERROR_UNKNOWN_PROTOCOL") != -1) {
alert("No handler registered");
}
}
}
In order for this to work you also need to have a hidden link somewhere on the page, like this:
<a id="testprotocollink" href="custom://testprotocol" style="display: none;">testprotocollink</a>
It's a bit hacky but it works. The Firefox version unfortunately still pops up the default alert that comes up when you try to visit a link with an unknown protocol, but it will run your code after the alert is dismissed.
You can try something like this:
function OpenCustomLink(link) {
var w = window.open(link, 'xyz', 'status=0,toolbar=0,menubar=0,height=0,width=0,top=-10,left=-10');
if(w == null) {
//Work Fine
}
else {
w.close();
if (confirm('You Need a Custom Program. Do you want to install?')) {
window.location = 'SetupCustomProtocol.exe'; //URL for installer
}
}
}
This is not a trivial task; one option might be to use signed code, which you could leverage to access the registry and/or filesystem (please note that this is a very expensive option). There is also no unified API or specification for code signing, so you would be required to generate specific code for each target browser. A support nightmare.
Also, I know that Steam, the gaming content delivery system, doesn't seem to have this problem solved either.
Here's another hacky answer that would require (hopefully light) modification to your application to 'phone home' on launch.
User clicks link, which attempts to launch the application. A unique
identifier is put in the link, so that it's passed to the
application when it launches. Web app shows a spinner or something of that nature.
Web page then starts checking for a
'application phone home' event from an app with this same unique ID.
When launched, your application does an HTTP post to your web app
with the unique identifier, to indicate presence.
Either the web page sees that the application launched, eventually, or moves on with a 'please download' page.

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