PDF.js HTA, promise being rejected - javascript

I'm trying to develop an HTA for extracting and processing the data from PDF files for a number of people in a large office. I've been looking into using the PDF.js package for this, but I've not been able to get it working.
I've forked the project and created an HTA version of the helloworld example with the compatibility.js file included. I can get an HTML version of this working on Firefox and IE11 through a gulp server, but the HTA doesn't give any output - no text, no error messages.
After peppering the source files with alert() statements, I've discovered that the original hello.js file is missing promise reject function, and that this fires when added, but here where my I meet the limits of my knowledge. I don't really know an awful lot about promises, so I don't understand why this one fails. Is this solvable or does it mean that the package simply won't run in an HTA?
EDIT:
I've been looking more into this and the failure doesn't make sense.
Tracing the logic through, the hello.js file calls the function api.getDocument from api.js. Following this back, there is only one return statement and the alert statement just before this line is running. However the fulfilled function is not triggering.
From my very limited understanding, the failure clause on a promise will be triggered from a throw() statement within the asynchronous operation. If that is the case then I would expect that operation to immediately cease and the reject function to trigger, but why would the line immediately before the return statement still run?
I did pursue one theory that this line from api.js was the one throwing the error:
}).catch(task._capability.reject);
To check this, I added an alert statement to the reject() function statement in util.js, but it did not trigger, so I can't tell where the error is coming from.
Is anyone able to give me any additional pointers to help me trace this down?

Solved!
By changing the compatibility setting to IE10 instead of IE9 (which I didn't know I could do) I got a more useful error in the right place. Looking more into this, this issue appears to be a duplicate of this one:
Access denied in IE 10 and 11 when ajax target is localhost

Related

Debugging JavaScript in client

I'm facing an issue while debugging my application. Following is the architecture:
Server: Java (Servlet)
Client: React+D3
Problem: Whenever, I change some react or d3 code and if an error occurs then it just shows me that some react (or d3) error has occurred but never tells me which function the error occurred (as seen in snapshot). Now, I know that simply debugging it by having the information like variable name and searching where I defined that variable. However, situation becomes tough when I use same object multiple times (say window) and had made several changes in the code. In this case, a specific line number where the error occured can be handy and quick. Let me know if I'm missing some basics about debugging such applications?
EDIT1:
1. In the snapshot, http://localhost:8080/..../Server Server is the main servlet application, kind of launchpad, which triggers several other react-based js files.
2. The mentioned ReferenceError is inside a function updateWindow() but the console never mentions this (and that's my problem).
PS: I'm using Eclipse tomcat on server-side
I think there's no straight forward solution to this problem. So, I'll post the method that worked for me with few additional points:
Problem: It doesn't gives a nice error trace like standard Java application, probably because it mixes with JavaScript code.
At every line of the error trace, line:column specifies the error line. I used this as a reference and started manual debugging from where my application launches i.e. Server.java and look where I defined the createChart() in the JS file and drill-down until I found the referenced variable.
In case of ReactJS' error (an error after resolving reference issue), I debugged it with normal react.js (not minified version react.min.js) so that it shows me exact line of error. Minified version is cluttered and is useless while debugging.
PS: If someone has better answer I'll edit this in future.

Testcomplete obj.$get("attrName") vs obj.attrName

I am working on a projet in Testcomplete 12.0.122 with javascript. I have a problem when I read an XML file and create a CSV file with the needed data.
Reading xml with Msxml2.DOMDocument.6.0
Write in CSV with aqFile.OpenTextFile
When the XML file is quite huge (above 200Mo) the execution start to take long (since the project need to be execute on a vm with 1 processor and 4Go RAM.
To speed up my execution someone told me to change all the call from the object Sys.OleObject.
Example : I got a call like xmlDoc.item(0); I change it for xmlDoc.$call("item", 0);
same thing for the attribute : I got xmlDoc.length change to xmlDoc.$get("length");
This increase speed, but i would like to know why exactly, the person who told me to do it didn't know really why.
Because i got a problem since I made my change, when the file are big, sometime I got error like Log.Error or Log.PopLogFolder doesn't exist. And those function are Testcomplete function for logging.
Any thought on the reason of those errors? Cause since the new call are faster I would like to keep them.
TestComplete 12.0 was the first version that has JavaScript and, perhaps, there were some issues with it. Install the latest version which is 12.10 by the moment and, perhaps, these issues will gone.
As for the reason of the better speed with the changed calls, I think that the reason is that these methods are lower level methods comparing to the usual methods which produces some overhead.

Programatically retrieve count of javascript errors on page

I'd like to write a test case (using Selenium, but not the point of this question) to validate that my web application has no script errors\warnings or unhanded exceptions at certain points in time (like after initializing a major library).
This information can easily be seen in the debug consoles of most browsers. Is it possible to execute a javascript statement to get this information programatically?
It's okay if it's different for each browser, I can deal with that.
not so far read about your issue (as far as I understood your problem) here
The idea be the following:
I found, however, that I was often getting JavaScript errors when the page first loaded (because I was working on the JS and was introducing errors), so I was looking for a quick way to add an assert to my test to check whether any JS errors occurred. After some Googling I came to the conclusion that there is nothing built into Selenium to support this, but there are a number of hacks that can be used to accomplish it. I'm going to describe one of them here. Let me state again, for the record, that this is pretty hacky. I'd love to hear from others who may have better solutions.
I simply add a script to my page that will catch any JS errors by intercepting the window.onerror event:
<script type="text/javascript">
window.onerror=function(msg){
$("body").attr("JSError",msg);
}
</script>
This will cause an attribute called JSError with a value corresponding to the JavaScript error message to be added to the body tag of my document if a JavaScript error occurs. Note that I'm using jQuery to do this, so this specific example won't work if jQuery fails to load. Then, in my Selenium test, I just use the command assertElementNotPresent with a target of //body[#JSError]. Now, if any JavaScript errors occur on the page my test will fail and I'll know I have to address them first. If, for some strange reason, I want to check for a particular JavaScript error, I could use the assertElementPresent command with a target of //body[#JSError='the error message'].
Hope this fresh idea helps you :)
try {
//code
} catch(exception) {
//send ajax request: exception.message, exception.stack, etc.
}
More info - MDN Documentation

JavaScript - is it possible to force code execution after an error?

I'm trying to make a PoC of reflected Cross-Site Scripting on a website that I'm testing right now. I've found a place inside of a Javascript code where commands can be injected, however the trouble is that there the previous block of code throws a 'not defined' error and therefore (at least I think so) my injected code is not executed. Is there any chance to execute the code anyway?
Here is the code:
UndefinedObject.Init({
Var1:"a",
Var2:"b",
Var3:"can_be_injected_with_JS_code")}
I can't inject any HTML tags as these are filtered by the application.
Many thanks!
Wrap them under try catch block.
In a sequence of execution, if the code fails, the remaining part will not be executed. Javascript errors ("Exceptions") can be caught using try...catch (if you are able to inject this try - catch also).
If there is a different flow (via another event), the code will continue.
You can either try using a try-catch, or if that won't help, try using window.onerror
Generally the right way of doing that is using try-catch-finally or try-finally:
If you make something about the error - log or do something else. Catch may be also used to execute your code, but not a good practice. You can do nothing about the error if you want, that`s why finally is used.
Finally is used when it is important to execute a piece of code, no matter if an error is thrown or not. For example in C++ or other language when you work with files inside finally the file is closed ( you can not leave it opened ). Look here for some examples.

Ajax problem using MooTools/jQuery - p.onStatusChange is not a function

I get the following error in firebug in Firefox 3 with both MooTools and jQuery:
"p.onStatusChange is not a function".
I've noticed this error frequently in firebug since one of the latest updates of FF3. However, it has started appearing with code that hasn't been changed in some time and that was not reporting errors previously. The errors happens when ajax results are returned. It shows up in different applications that use separate javascript libraries, MooTools and jQuery.
Does anyone have any idea why these errors are appearing? My intuition tells me that it is something in Firefox that changed, but I can't find any information online currently. The ajax calls still work fine, but I am wary of just going with my intuition and leaving script errors in my code.
Thanks,
Jason
I get it in tabBrowser instead:
chrome://browser/content/tabbrowser.xml
(4) errors occur:
p.onStatusChange
p.onProgressChange
p.onStateChange
p.onSecurityChange
What I found was that the add-on "PDF Download" was causing these errors. The best way for me to check was to go to a page that produced the errors, turn off all the add-ons, and turn them on one-by-one (starting with Firebug). Instead of going one-by-one, I actually turned them on in lots of 3 to help identify the problem sooner.
Here is the reference for the function NsIDownloadProgressListener. It looks like it has been deprecated.

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