How can i make my code wait until the page load completely in Nodejs?
I use selenium-webdriver version 4.0.0
const driver = new Builder().forBrowser("firefox").build();
await driver.get("http://www.tsetmc.com/Loader.aspx?ParTree=15131F");
// here we should wait but how?
There are 2 concepts here - there is:
Page Load time - time for the page and content to download (...this downloads the scripts), then....
Script load time - time for scripts to run, get more data and populate the page
Page load time is relatively easy - but this is enabled by default and might not help much if you're already experiencing issues.
For script load time, you need an object to synchronise on.
The selenium docs give a good outline of different wait strategies and provide code examples for different languages.
Looking at your page, you will mostly likely want to try the explicit wait. In Javascript this is:
await driver.wait(until.elementLocated(By.id('foo')), 30000);
You can update the By identifier to be the LAST item on the page or, use this approach for each item you need to interact with.
The same pages also lists other expected conditions too depending on the state you need.
A quick final note, if you're not aware selenium 4 is still in alpha. You can access it if you need the new features but they're still being testing and it is subject to frequent change. If you don't need selenium 4's new features, you might want to roll back to latest stable version.
Related
I have a small application with two pages: the login page and the main page. My problem is that when I use just one main JavaScript file for both pages (like it's recommanded) I get a lot of ReferenceError because some variables on a page are not defined on the other one...
e.g:
Line of code for the login page
copyrightYear.textContent = new Date().getFullYear();
Main page complains
Uncaught TypeError: Cannot set property 'textContent' of null
How can I fix that? Don't tell me I have to say if(copyrightYear) { do stuff } everytime, it's just a nightmare if I have to do that for every variable
Two answers for you:
The recommendation isn't a dictate
My problem is that when I use just one main JavaScript file for both pages (like it's recommanded)
That's a very general recommendation. It doesn't apply to every situation. There's no point in loading code in a page that won't use that code.
If you have code that you use in both pages, and also page-specific code, it's absolutely fine to have a file that both pages share and also page-specific files:
<script src="main.js"></script>
<script src="page1.js"></script>
If you're really worried about the extra HTTP request (much less of an issue these days than it used to be), use modules and a bundler like Webpack or Rollup that will create a bundle combining the main module with page 1's module for page 1 and another bundle combining the main module with page 2's module for page 2.
But even then, the extra HTTP request may be better for your users, if you expect them to go from page1 to page2 in a reasonable timeframe. The reason is that if you have main.js and page1.js/page2.js and you allow caching of them, when the user goes to page1 they get main.js and page1.js, and then when they go to page2 main.js comes out of their local cache and they only have to load page2.js. In contrast, if you had a single bundle file for each page, they'd have to re-download all of that common code when going from page1 to page2 (or vice versa). But if you expect a visitor to visit either page1 or page2 but not the other one, you save the HTTP request by using page-specific bundles.
There's really no one-size-fits-all solution. :-) There are all sorts of considerations.
Note that HTTP/1.1 made additional HTTP requests more efficient and is nearly universally supported, and HTTP/2 makes them a lot more efficient, effectively eliminating the case for reducing the number of HTTP requests as part of the page startup. All major modern browsers support HTTP/2 as do up-to-date web servers.
Put the code for each page in a function
If you really want to keep a single page, put the code that's specific to each page in functions for those pages, and then have code in the main part of the file call the appropriate function based on location.pathname.
You figured it out, you have to check this for every variable. But generally it's much more convenient to use functions and only call these functions when you need them.
So for example, say you want to set some copyrightYear (even tough this shouldn't be set via JS, you should generate this on Backend side to have it in the source code)
You have something like this:
function updateYear() {
// here you do your magic of selecting the element, setting the year, whatever.
}
// another function, totally unrealted to updateYear()
function toggleMenu() {
// some function where you toggle the menu if you click somewhere
// like: button.addEventListener('click', () => {} );
}
And in your JS file you have one block where you call all these functions:
if (document.querySelectorAll('.elementForYear') {
updateYear(); // here we call it because we are sure this element exists... so everything inside function must work
}
if (document.querySelector('.myMenu') {
toggleMenu(); // if the element myMenu exists, we know we can add these toggle Functionality.
}
You can also add these if inside the function and call the function regardless of if it's needed or not, that's up to you and up to coding guidelines.
Generally I find it makes sense to have one function only rely on one (or max two to three elements if it's some toggling of other elements) ... And then you just check for one element. And if this one element exists you can go ahead and call the function.
Can you give some tips of what and where to check in order to improve my Meteor app loading performance? Currently my app is taking almost 15 seconds to load completely, which is insane.
I see the major loading time is in scripting (yellow) and the XHR bar is taking almost 6 seconds.
When I click on the scripts I can't get to my script names in order to review loops and indexes. All I see are function calls with function names not related to my own code, probably related to packages. Function names are like:
s.xhr.onreadystatechange # afaec39….js?meteor_js_resource=true:60
I have checked my subs/pubs and all of them are available on client within the first second.
#Ruben, let us know what you learned, if you were able to reduce meteor load time.
You are absolutely right with your assumption for Meteor build - it will perform the JavaScript code minification.
You should try running the performance recorder on localhost and - in the best case - it should give you a more detailed insight on how things really are.
Edit: Note that I found the root of my problem after help from #ernst-zwingli, so if you have this same error one of his noted fixes might help you out. My problem is a known issue with Protractor itself, if you think this may be you, I've expanded on my steps to pinpoint the root of the problem after my original question.
I'm trying to use Protractor in an Angular2 (just Angular) application built using angular-cli.
My problem: Elements on an Angular app page are not being found when browser.waitForAngularEnabledis at it's default setting of true (as in 'I believe I am on an angular page and would like for Protractor to do it's magic'). They are being found just fine if I set browser.waitForAngularEnabledto false (as in 'I am not on an angular page and would like to handle this myself, take a seat Protractor'). How do I track down what's causing this on my definitely Angular pages?
I have a product with a non-Angular Auth0 login page that gates access to the rest of the product that is written in Angular (Angular 4.3.2 to be exact). I have successfully traversed logging in on the non-Angular login page. I flipped the waitForAngularEnabled switched to false to facilitate the non-Angular login. I turned it back to true at the point where I expected my initial landing page (Angular) to be loaded, after clicking the submit button. Code is as follows:
browser.waitForAngularEnabled(false);
browser.driver.get('https://dashboard.net/projects');
browser.driver.sleep(10000);
browser.driver.findElement(By.css("[type='email']"));
browser.driver.findElement(By.css("[type='email']")).sendKeys("email#example.com");
browser.driver.findElement(By.css(".auth0-label-submit")).click();
browser.driver.findElement(By.id("passwordInput")).sendKeys("password");
browser.driver.findElement(By.id("submitButton")).click();
browser.driver.sleep(5000); // needed if not waiting for Angular
//browser.waitForAngularEnabled(true); // Back to Protractor land we go
let elementToFind = element(by.className("header-text"));
elementToFind.isDisplayed().then(function() {grabTheDarnLocalStorage()});
expect(elementToFind.isDisplayed()).toBeTruthy();
If I uncomment the browser.waitForAngularEnabled(true); line to state that I'm back in Angular code I get the error trace as follows:
Failed: Timed out waiting for asynchronous Angular tasks to finish after 30 seconds. This may be because the current page is not an Angular application. Please see the FAQ for more details: https://github.com/angular/protractor/blob/master/docs/timeouts.md#waiting-for-angular
While waiting for element with locator - Locator: By(css selector, .header-text)
ScriptTimeoutError: asynchronous script timeout: result was not received in 30 seconds
(Session info: chrome=61.0.3163.100)
(Driver info: chromedriver=2.32.498550 (9dec58e66c31bcc53a9ce3c7226f0c1c5810906a),platform=Windows NT 10.0.14393 x86_64)
at WebDriverError (C:\Users\c-shouston\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\error.js:27:5)
at ScriptTimeoutError (C:\Users\c-shouston\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\error.js:203:5)
at Object.checkLegacyResponse (C:\Users\c-shouston\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\error.js:505:15)
at parseHttpResponse (C:\Users\c-shouston\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\http.js:509:13)
at doSend.then.response (C:\Users\c-shouston\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\http.js:440:13)
at process._tickCallback (internal/process/next_tick.js:109:7)
From: Task: Protractor.waitForAngular() - Locator: By(css selector, .header-text)
I've referenced the FAQ: https://github.com/angular/protractor/blob/master/docs/timeouts.md#waiting-for-angular
I have my devs stating that they don't use $timeout (they use (Edit: NOT $interval) Observable Interval thank you very much) and they're not sure about $http.
I found this solution about the canonical way to debug protractor Angular sync issue issue: Canonical way to debug Protractor-to-Angular sync issues
but I'm not sure the solution works without access to modifying the dev code to run the programmatic tracker. (Edit: I never did figure out how to get this to work)
I also found this about a long timeout you add before each test, but I feel this is unnecessary overhead that makes your overall test execution take longer than it should without understanding the root cause of the problem: https://stackoverflow.com/a/37217167/2718402 (Edit: yeah, this is a bad idea and adds unnecessary time to your tests, please don't do this)
The frustrating bit is that this seems to be a common occurrence and there doesn't seem to be a streamlined documentation on how to deal with it. Logging in with a non-Angular page only to transition to an Angular page. Angular pages not being picked up properly by Protractor. All of the examples I find online are bits of code that I don't have a reference for where they should be at in my overall test framework. I would kill for a full example of someone testing a non-Angular login that transitions to a fully Angular website, with a setup config and real world test cases. (Edit: This is still true, but I can't make one myself as my application is in a bad grey area, note my RCA below for more details.)
I just want the ability to do my login and then successfully transition over to my Angular pages and be able to rely on Protractor to work with my Angular pages. I need to know what to look for that may be a long running asynchronous process (What specifically can I check for in the Chrome dev tools?). I would love to understand what Protractor needs as defaults in order to successfully work with the Angular parts of my app/website (Is there something beyond the presence of <app-root _nghost-c0="" ng-version="4.3.2"> in the HTML?). Before this job I worked in Java, so all of this asynchronicity and Angular is new to me, so I know I'm missing the known things that a seasoned Javascript dev is aware of.
My Solution/Root Cause Analysis
Starting down the list suggested by #ernst-zwingli:
for Angular(2) Check if the object window.getAllAngularRootElements returns at least one value.
It returned at least one value, so I moved on.
useAllAngular2AppRoots: true,
I tried this and still ran into the async timeout.
And if $interval or other long lasting asynchronous tasks are used, there can be issues, because of the zones
Previously #ernst-zwingli also mentioned looking at the testability method, except it was the old way. Through research and testing I found the window object also has a getAllAngularTestabilities method. This led down an interesting rabbit hole. An example output from the Chrome console (put window.getAllAngularTestabilities() in the Chrome console window, look at the resulting list) is as follows:
t:
_callbacks:...,
_didWork:true,
_isZoneStable: true (this looks promising, but why isn't Protractor working then?!?)
_ngZone:
hasPendingMacrotasks: true,
hasPendingMicrotasks: false,
isStable: true
I would think isZoneStable would be enough, but apparently not so for Protractor. Then looking at Macrotasks being true, I had to look up what the heck a Macrotask was: What does hasPendingMacrotasks and hasPendingMicrotasks check for?.
A macrotask can be:
i.e. setTimeout, setInterval, setImmediate
Thus #ernst-zwingli's note about interval's causing problems in the zones was remembered and something finally clicked.
First github issue, about zone instability
Another github issue complaining about the necessity of using browser.driver to get things done along with browser.waitForAngularEnabled. Apparently this is expected behavior, it led me to issue #3349
Issue #3349 - The actual root cause of my issue. My developers do not actively jump in and out of zones around observables. Even though these observables only have one subscriber. Since they live in the angular zone at this time, they are a long running "Macrotask" that Protractor waits infinitely on.
I can't rewrite the code with these wrappers as I am not currently versed enough in Angular to do it safely and we are currently hurtling toward a November deadline. I think I'll have to deal with using browser.driver for the time being and hope I can't get it fixed later. Hopefully my RCA was helpful for you.
In the following I list a set of potential causes and possibilities to fix/resolve them.
How does AngularJS and Angular(2) Work / What can I check in the Browser Dev Mode
I can't explain it as well as Andrey Agibalov in his Blog here, so check it out (also for developers).
Basically, the objects required by Protractor you can check in your Chrome Dev.
for AngularJS
Check if the object window.angular is properly defined, i.e. lookup window.angular.version and also try window.angular.getTestability of your Root element
for Angular(2)
Check if the object window.getAllAngularRootElements returns at least one value.
Root Element (AngularJS)
Potentially your Angular App is somewhere wrapped within the Body as something like <div ng-app="my-app">.
In that case, you must adjust your rootElement: body inside config.ts. Check this answer for details.
Angular(2)
If you're using Angular (aka Angular2), then there are ngZone's introduced. In this case your config.js should additionally contain this:
exports.config = {
framework: 'jasmine',
seleniumAddress: 'http://localhost:4444/wd/hub',
specs: ['spec.js'],
useAllAngular2AppRoots: true,
// rootElement: 'root-element'
};
check in your browser for window.getAllAngularRootElements as the additional line in conf.js is about this.
If you can, maybe use the advantage of multiple zones possible. Create a 2nd zone, configure rootElement: 'root-element'
to only focus on one zone and then move some asynchronous tasks into the other zone until you found, which task(s) lead to timeout. Keep those tasks (if possible) in the separate zone, so Protractor ignores those tasks.
And if $interval or other long lasting asynchronous tasks are used, there can be issues, because of the zones. Repeatedly or long lasting tasks should be started outside the zone and then be moved into the zone as else Protractor could run into timeouts. There is a workaround for developers to apply, in order to avoid these problems for Protractor.
read all about it here
browser.driver. - side remark
browser.driver.get() works as if ignoreSynchronization = true, since you directly assign the Browser Driver and you kind of bypass the synchronization logic of Protractor.
Read more about it in this answer here.
Hope I could give you some more input and you can solve your issue. Please let me know the results.
Could you please set
browser.ignoreSynchronization = true;
and try
i want to use SCORM (ver. 2004) using multiple html pages and i need to switch them using location.href
when im using only 1 html file its working as intended.
when using multiple files and switching them off with location.href, we get no connection on the new page and cannot initialize new connection because its already initialized.
Thank you very much for your help.
So the connection being Initialized isn't a big deal. But, each page loading and trying to initialize just generates a SCORM warning/error. That technically is a non-actionable error.
Cons of this approach
JavaScript has to instantiate on each page - each time. This means it has to pull back down (depending on the features your using) bookmarking, suspend data, etc...
So this is where mitigating all this becomes problematic.
When do you terminate?
How can you bookmark or support bookmarking?
What happens if curriculum adds or removes a page later?
Can I limit the number of times I try to initialize?
Will the LMS even allow this (since sometimes they salt and pepper values in the query string)?
The share-ability barometer on doing this I'd say is ripe with failure and I'd caution against it. Some LMS systems even detect the unload. Can you over come some of the above - sure. But will you be over taken by the rest... absolutely.
SCO = Shareable content object. And anything that diminishes the shareable part will hurt downstream.
Alternative
Use a single page SCO collection defined in a imsmanifest.xml. See https://github.com/cybercussion/SCOBot/wiki/Single-Pages-Managed-by-LMS-Navigation
Comment
Hope that helps. I was involved with a project a very long time ago where a architect wanted to do things simple like this, and it really requires some added elbow grease to either support single pages managed by the LMS, a AJAX or IFRAME approach to do it right.
I've set up a simple testbed for WatiN (ver 2.1) which reads:
var browser = new IE();
browser.GoTo("http://www.google.co.il"); // webpage doesn't matter really
browser.RunScript("alert(123)");
This works only if KB3025390 is not installed. Installing it breaks the above test with an UnAuthorizedAccessException which has HRESULT set to E_ACCESSDENIED. What gives? Is there any workaround?
Update: Using IWebBrowser2.Navigate2 along with "javascript:console.log(123)" type of scripts works however
it makes me feel uneasy using such a backchannel
the scripts run through this back-channel of .Navigate2() may only have a max length of about 2070 chars (give or take) otherwise they get forcibly truncated to this length leading to javascript errors upon attempting to run them
using .Navigate2(), even with the most trivial script, will clog the ready state of Internet Explorer for good in the sense that it will be set to READYSTATE_LOADING without any hope of getting rid of it. In simple terms this means that once you use this hack, you either have to perform every single subsequent operation in WatiN in a "dont-wait-for-webpage-to-load" fashion (GoToNoWait, ClickNoWait etc) lest your code freezes upon waiting for the browser to turn back to READYSTATE_COMPLETE (which will never come about ofcourse as already mentioned).
there appears to be a much broader issue here in the sense that I can't even access the properties of an IHtmlWindow2 object p.e. window.document throws an unauthorized exception again making it virtually impossible to transfer over to the C# world the return-values of the scripts I'm running (using Expando etc) for documents other than window.top.document (for the window.top.document window there is IWebBrowser2.Document which does the trick)
Update#2: The folks over at the selenium project have also noticed this issue:
https://code.google.com/p/selenium/issues/detail?id=8302
A bug report has been created as well:
https://connect.microsoft.com/IE/feedback/details/1062093/installation-of-kb3025390-breaks-out-of-process-javascript-execution-in-ie11
Update#3: IHTMLWindow2.setInterval and IHTMLWindow2.setTimeout also throw UnauthorizedAccess exceptions. These methods are not marked as deprecated in:
http://msdn.microsoft.com/ko-kr/library/windows/desktop/aa741505%28v=vs.85%29.aspx
yet they have wounded up suffering from the same cutbacks all the same.
Update#4: I gave the approach recommended in this post a shot:
https://stackoverflow.com/a/18546866/863651
In order to dynamically invoke the "eval" method of the IHTMLWindow2 object (or any other method really). Got the same "System.UnauthorizedAccessException" as above. So no joy here either.
Microsoft recommends using "eval" over "execscript" however after the above experiment I suspect that they are refering to accessing "eval" only from within the browser.
As far as I can tell thus far, when it comes to the full-fledged IE11+ using "eval" out-of-process (via COM) appears to have been completely prohibited along with any other function-invocation of the window object, the only exception being the back-channel of the .Navigate2() mentioned above.
It turns out Microsoft eventually backpedaled on its decision to kill off .execScript at COM-level. Just install the latest updates for Windows including kb3025390: One of the updates for IE that came after kb3025390 brings back .execScript functionality at COM-level
Note, however, that .execScript is not accessible through IE's javascript anymore. In that context it's gone for good.
fyi: this one is also not working
ieInstance.Document.Script.<methodNameString>(<commaSeperatedParameterString>)
try this worked for me at some places but not all places
ieObject.Navigate "javascript:<methodNameString>(<commaSeperatedParameterString>)", Null, "_parent"
or
ieObject.Navigate2 "javascript:"<methodNameString>(<commaSeperatedParameterString>)", Null, "_parent"
now trying to find out solution using eval
I have found a way around the problem of an update installing automatically. You can just create a simple batch file with following content.
{code}
#echo off
wusa /uninstall /kb:3025390/quiet /norestart
END
{code}
Then go to task scheduler, create a new task for this batch file to run every one hour or day as per your requirements. Add it as a system task so it runs in the background and does not affect the running automations.