How do I find the context in which document.write operates. Can you solve the riddle - document.write

Basically i have these two lines of code written right after each other.:
console.log(typeof (noAdsCallback));
document.write('<sc' + 'ript type="text/javascript">console.log(typeof(noAdsCallback));</scr' + 'ipt>');
The first one logs function, the second logs undefined.
Of course it's a bit trickier than that. So here is the set-up in a nutshell:
I have a so called waterfall of ad-providers. That means, I try to load some Ads, by writing (using document.write) some special tags (given to me by my ad-provider).
If the provider doesn't find an ad for me, they send back a javascript-snippet which looks like this:
if (typeof(window.noAdsCallback) === "function") noAdsCallback();
This function essentially writes the tags of the next provider, which does the same as the first one until I reach the end of the list.
This system actually works fine, doing exactly what I want it to do. Both lines given in the beginning log function.
Except if I use Google as an ad-provider. There is one thing Google does differently, which seems to mess everything up.
In Google, I cannot define a fallback-JavaScript-snippet. All I can do is provide a fallback-url. So this fallback-url (since it's loaded inside an iframe inside an iframe inside...) sends a postMessage to the top, which then calls the same noAdsCallback() method. And this too, works just fine. The message is received and the right method executed. However, already the two lines already give different results, i.e. function and undefined respectively
The next provider then fails to find the noAdsCallback() Method, when it returns, because it uses document.write to try to execute it. Somehow, the context was lost.
First hint: It works fine (i.e. both lines log function) in Chrome, but it doesn't work in FF or IE.
Second hint: It works fine, as long as context never switches, but if communication runs at any point through messaging, it get's confused.
Third hint: Using the fantastic postscribe library as mentioned below, actually solves the problem, but introduces new ones somewhere else.
Fourth hint: Debugging the window.name, before using document.write, gives the correct name, so I'm not in a random iFrame.
Finishing thoughts. I know, i know: DON'T USE DOCUMENT WRITE!! I know that. But since Adproviders use it all the time, I am forced to use it to, otherwise I get this:
Failed to execute 'write' on 'Document': It isn't possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.
In Fact, right now I'm using postscribe (https://github.com/krux/postscribe) and it works like a charm, except for one lousey provider. And the workauround solution would be, to use document.write only for this lousy provider and postscribe for all the others. But i would really like to find out what the root of the problem is.
Any Ideas, much appreciated.

I think I understood it now. Long story short: DON'T USE DOCUMENT.WRITE :)
Try postscribe, if you have to.
So in hindsight it is quite obvious, because really, anywhere you read about document.write() it says, that write() clears the whole document. And I just didn't get it, because I never saw it happening and every ad is using it, like the whole time. Plus, it seemed to work fine on Chrome. So what's going on??
Well here is what happens. As long as the document is open, which basically means while it is being written, document.write() just appends to the stream, and doesn't clear the document. And as long as I used document.write(), to append foreign ad-scripts (which may and will contain document.write()), the page does not close, hence the document stays open.
This is the reason, why adding Google to my waterfall, posed a problem: Google puts everything in iframes. So the page containing the waterfall model just sees the iframe and says: "well as far as I'm concerned, I'm done" and closes the document, while in fact, Google is still at it.
Afterwards, Google didn't find an ad, sends a postMessage to the main page, causing the next provider to be used. Who then uses document.write() and clears everything.
Everything? Not everything. Remember, it still used to work when I used Chrome? The reason for that is, Chrome just clears the HTML but leaves the Javascript intact. So on Chrome, my Javascript-waterfall worked fine, because all the JS-objects where still in place. All other browsers cleared it.
So that's it. Probably noone's gonna read it, but if you do, USE POSTSCRIBE! Now that I finally really understood document.write() and document.open() and document.close() I'm a big fan.

Related

Not able to set list2 in Adobe Launch in custom code

I am trying to set list2 in my analytics call through custom code but it is not getting set.
This issue comes with s.tl() only while with s.t() method, it is triggered correctly.
Below is the code :-
s.addEvent("event12", true);
s.linkTrackVars = "list2";
s.list2 = "Data"
s.tl(this, "d", "Download", s);
If I place logger just before beacon call, it shows the value. However, when I click the button and check for same, only "event12" get fired and not "list2".
Any help would be highly appreciated.
Just tested your code on lululemon:
Conclusion:
You're overwriting either the listvar or the linkTrackVars somewhere else. As #Crayton Mentioned above, doPlugins would be a good spot for it.
But it actually can be overwritten anywhere. In any rule that fires prior, or the s code, or any DE affected.
Paste your code into the console. Execute. Do you see the listvar populated? If yes, then your problem is in rules, so check them. You're not supposed to reassign linktrackvars. Always use the s.apl() plugin.
If no, however, then your problem is definitely in doPlugins. Sometimes I have it when I have silent catches in s code. Pageviews would have all vars populated, but links would have mixed results. Check your error reporting in the catches in doPlugins. I suggest having all code in doPlugins in a try catch.

How can I optimize Robot Framework to speed up testing of an Angular application?

I know the basics of optimizing Robot Framework for speed on normal applications, but this is not a normal application. It's not a question of going as fast as possible, because if the code executes too fast on an Angular application, it'll try to click an element that isn't enabled or visible, or an element that doesn't exist yet. Timing issues abound, and the result is that I'm using a keyword (below) to slow down my program universally. The problem is that it's hard-coded, and I'm looking for a more "programatic" (programatical? I don't know the exact term) solution that will wait for an element to be clickable and then click it as soon as it is.
This is the keyword I use after every single click (${SLOW_TIME} is a global variable set to 0.5s):
Slow Down
# EXAMPLE USAGE
# Slow Down ${SLOW_TIME}
[Arguments] ${SLOW_TIME}
Sleep ${SLOW_TIME}
This is my current solution, which was written to verify that an element is ready to be clicked for test verification purposes, not speed. It's not complete (needs "Is Clickable") and occasionally causes the program to wait longer than it has to:
Verify Element Is Ready
# EXAMPLE USAGE
# Verify Element Is Ready id=myElementId
# Click Element id=myElementId
[Arguments] ${element}
Variable should exist ${element}
Wait until element is visible ${element}
Wait until element is enabled ${element}
I'm aware that Robot Framework isn't built for speed, but for long tests I'm tired of doing nothing for 10 minutes waiting for it to finish, only to see that I have an incorrect [Fail]. If the solution involves Python, Javascript, or Java, I can work that in.
EDIT: I'm currently using ExtendedSelenium2Library, but its implicit waits don't always work, so I wanted a second layer of waiting, but only as long as necessary.
First solution to explore would be to use libraries specifically designed for Angular based web applications, such as AngularJsLibrary or ExtendedSelenium2Library. As far as I know, ExtendedSelenium2Library is the one that works best (but perhaps not without any issues, I think it does have a few issues)
Next thing to know is, given that your element indeed is visible, it doesn't necessarily mean that it's ready to be clicked. There are quite a few ways to get around this kind of issues.
One way is to put a sleep in your test setup, to give the page some time to fully initialize. I'm personally not a fan of this solution. This solution also doesn't work well for pages that load new content dynamically after the initial document was initialized.
Another way is to wrap your click element in a wait, either by writing your own in Python or, using something like Wait Until Keyword Succeeds

AngularJS: is there a debug mode for typos in bindings?

I've just wasted half an hour hunting for what turned out to be...
<select.... data-ng-options="x as x.name for x in customerController_clipped.options"
instead of
<select.... data-ng-options="x as x.name for x in customerController_Clipped.options"
That is, a one-character typo - in this case, a 'clip...' instead 'Clip...'
Sure, it's easy to see it when it's isolated above - but think of this inside huge HTML content, and you now know why I ask:
Is there a way to ask AngularJS to report any failures in names of bindings, to ease our debugging? A simple console logging of this kind of failure would suffice, instead of a silent operation that leaves our components empty...
I can't see anything built in for doing this, though maybe you could raise with angular.js as a feature request, or try writing a pull request for putting an option in $parseProvider? If you want to do this the only way I can see right now is by altering the code in the $parse service which does the interpreting of any expressions.
I've plunked a quick test to see how easy it is. The original code is from angular 1.1.5. Search for ANDYMOD in the angular-1.1.5.js file to see the code I've edited. This basically adds a console.log for whenever the y and z parts of a 'x.y.z' expression are undefined or null, rather than ignoring it.
This is in no way a production-worthy solution, and doesn't work it you want to use ng-csp, but it shows something can be done at least. Maybe you can sub these few lines in if you ever need to test again...

Webkit GTK: Determine when a document is finished loading

There are other questions on StackOverflow which are close to what I want to know, like Webkit GTK :: How to detect when a download has finished?, but I think I'm asking something a bit different:
In general, in the event-driven C Webkit-GTK API there are a lot of events which may relate to the idea of when some document is finished "loading". The problem is the documentation is pretty sparse, and the idea of "finished loading" isn't necessarily clear, because it can refer to a lot of things. Does "finished loading" mean that the document is finished downloading? That it's finished creating the DOM tree? That it's finished downloading including all other resources (like CSS, JS and image files?)
Relevant signals are signal::notify::load-status, document-load-finished, and resource-load-finished.
The load-status signal fires everytime the load status changes, so you need to manually call webkit_web_view_get_load_status and check the status each time. Even so, when the status finally is WEBKIT_LOAD_FINISHED, I'm not sure what that means - does it mean WebKit is done downloading the resource, or that it's finished creating the DOM tree, or what?
Question:
What is the difference between the various "finished" signals, and is there any signal that is equivalent to the standard Javascript DOM event window.onload?
I believe the document-load-finished signal is what you are looking for as it seems (in my opinion) to match more closely what you are trying to test for.
One idea to test which is the correct way to do this would be to test the various ways there are to test if a document has "loaded" manually. I.e. Try the one I linked to above, and output a string to the Terminal when the value is true. If the value is true before the page has completely displayed all of its contents, chances are that it's not the one you're after. Then move on to the next, until you've got the right one.
Other than that, I'm not really sure what else you can do, since as you mentioned, the definition isn't very clear. It's times like these I wish Gtk documentation was a little more verbose.

silverlight: refresh to a specific url

suppose user navigated to silverlight page at root/myurl. When user presses f5 I would like the browser to fetch the content of root/, not root/myurl. Is this possible to accomplish?
What I would do is write a flag to your local storage that says, in effect, "'root/myurl' is the last URL I visited." And when when someone reloads "root/myurl", check to see if that flag exists. If it does, renavigate to "root/". It's a little complex, but something of that sort ought to work.
The other approach I usually take in these instances, where I find myself wanting behavior that doesn't match how the browser normally behaves, is to figure out why I'm doing things different from everyone else. Quite often (almost always), there's a better and more natural way to do it, if I'll just take a step back and figure out what I'm really wanting.

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