So I'm getting the following error:
Uncaught Error: Assertion Failed: The key provided to get must be a string, you passed undefined
Should be easy enough to fix, if there was any indication of the line in my code that causes that error.
Using the chrome console, I click on ember.debug.js:6254 next to the error, which just shows me the ember code that throws the error. I can expand the error, but I just get a bunch of functions that can't be clicked on and no indication where they come from.
Can someone please help me figure out how to identify the line in my Ember code that is causing the error.
I've gotten this error before. It happens when you call get() in any of its forms (Ember.get() or this.get() or get(this)) without a string as the name of the property you want to retrieve.
You should be able to find the source of the error by auditing your application for wherever you call get() and making sure you pass the property name as a string. E.g., Ember.get('model.someProp') or this.get('someProp') or get(this, 'someProp').
This should be a comment but I can't, so here goes:
Iam new to Ember and have been spending quite a long time debugging. Remember that long stack of function calls that chrome's console shows.
Look for anything other than ember.debug.js...especially those marked (anonymous function) and files with names vendor.js or app-name.js
Usually in software development when debugging your best friends are going to be console.log() or alert() (in the case of JavaScript). Usually you have to figure out if your getting what ever is that you passing to your function by consolelog everything until you find your bug. Ember sometimes will not tell you what is exactly the error because does not know where exactly is coming from.
...computers are annoying but we love them....
here are some articles from Mozilla developer and Google on how to debug JavaScript.
I had a NULL value in my database which I wasn't accounting for in my app. In my case, it shouldn't have been NULL in the first place, so after giving the record a value in my database the problem disappeared.
I agree the error message is not very helpful.
Related
Uncaught (in promise) SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data
This error occurs in Firefox console when loading 3rd party Javascript. But Firefox console gives absolutely no information as to whereabouts in the JS this issue occurs. The 3rd Party JS has a host of different JSON parts to it.
I am not familiar enough with JS to dig in and mess around with the code toooo much or spend hours fragmenting it and taking it apart and putting it back together again.
NOTE
There are a lot of questions with identical titles, and each of these show very specific issues with very specific responses. My question is not really about wanting to find the issue in this case (although that would be great).
My Question
How should I (any anyone else) approach trying to find where this error is;
How do we find what data is causing this error?
How do we find which line of JS causes this error?
Reading the MDN (etc) on JSON errors It seems to be easy to resolve once it's been found, but the case is I am having troubles finding how to go abouts digging out where in the JS this issue occurs and/or which data is causing the JSON error.
UPDATE
Further to comments, here is the Debug flow output from Firefox; I'm a little lost in here but this still doesn't seemt to show me what is actually going on.
Some clear pointers that came up in the comments below the question:
Use the Debugger Firefox Inspector tab before refreshing the page and reloading the error.
Somewhat unexpectedly, when on the Debugger tab, the same console error (at the bottom of my screenshot) this time shows a file reference and line number reference and can be clicked on to show a cascade of details.
As mentioned by evolutionxbox and Barmar the Debugger tab should also be showing the variable that's used in the call to JSON.parse.
Using the Debugger Breakpoints tickboxes was very useful for establishing what part of what code was running when the error was encountered.
More will be added here
I am getting this error after an AJAX call fails and I'm trying to log the error object by stringifying it and saving it to the sesssionStorage. The site is not in compatibility view or enterprise mode, it is IE11 and the doctype is <!DOCTYPE html>, the document mode is Edge and the user agent string is Default. This is only happening once in a blue moon so it's hard to track down what is happening. I haven't been able to get the error that is being thrown yet, however I will just create my own string that catches the details of the error that I need for now and then hopefully be able to move forward.
Has anyone else run into a situation where JSON should be available but isn't? Again, all the doctypes/compatibility settings are fine and this only happens once in a blue moon.
Read about stringify here.
The cause of your problem is that you try to call the stringify method of a variable which is a null reference or is undefined. To make sure this is not the case, validate your value to be a valid JSON:
function isNullOrUndefined(param) {
return (!param);
}
then before you call stringify for foo:
if (!isNullOrUndefined(foo)) {
//some code involving foo.stringify
}
Apologies Steve,
I'd been having a noobs stringify issue and couldn't find a solution anywhere while getting the same error message. I'm happy to admit here, in the hope it can help others, make sure you've updated to a recent version of jquery, I'd been using version 1.4.1 shipped with VS2010, now using 2.1.3 with the help of NuGet packages.
Hope it doesn't go against the rules or offend you, but this really does feel like the best place to offer out this info even though I'm sure it is of little support to you.
I just started learning Javascript and AngularJS and have a decent Java and C++ background.
Today I wasted an entire day debugging a trivial error that boiled down to a missing comma in a JSON file: "name": "Melbourne",
"snippet": "Melbourne"
"location":{"lat": "37.8136S", "long": "144.9631E"}
Now I'm wondering:
What's the Javascript/AngularJS way of debugging? - for this specific case as well as in general. Spending 8 hours changing every line in the code can't be the solution.
In C++/Java I would look at the stacktrace so i checked the chrome console output and found:
SyntaxError: Unexpected string
at Object.parse (native)
at fromJson (http://localhost:8000/app/bower_components/angular/angular.js:1078:14)
at $HttpProvider.defaults.defaults.transformResponse (http://localhost:8000/app/bower_components/angular/angular.js:7317:18)
at http://localhost:8000/app/bower_components/angular/angular.js:7292:12
at Array.forEach (native)
at forEach (http://localhost:8000/app/bower_components/angular/angular.js:323:11)
at transformData (http://localhost:8000/app/bower_components/angular/angular.js:7291:3)
at transformResponse (http://localhost:8000/app/bower_components/angular/angular.js:7963:17)
at wrappedCallback (http://localhost:8000/app/bower_components/angular/angular.js:11319:81)
at http://localhost:8000/app/bower_components/angular/angular.js:11405:26 angular.js:9778
How is this supposed to help me? I see nothing that even remotely tells me to check my JSON or my code - only library code. The offending lines in my code are
//citycontroller.js
$scope.cities= City.query();
//cityservice.js
cityServices.factory('City', ['$resource',
function($resource){
return $resource('cities/:cityId.json', {}, {
query: {method:'GET', params:{cityId:'cities'}, isArray:true}
});
}]);
Why isn't there a stacktrace for either of these lines?
I spent most of yesterday dealing with nearly the same issue.
A lot of the Angular error messages will actually provide a link that you can click on and it'll take you to an Angular page that provides a more detailed error message.
This feature doesn't seem to have made it to the parser, yet.
The stacktrace probably should include a reference to your code but maybe it's too far down or maybe it didn't make it in there because the problem isn't with your code, it's the library the blew up.
My clues in these error messages come from the first few lines:
"Unexpected string" = I'm getting a string when I don't expect one
"at Object.parse (native)" = I was trying to parse through some data
"at fromJson" = I was parsing JSON data when I crashed
My error was nearly the same but I got "Unexpected token ," which means that it found a comma where it didn't expect one.
As for other Angular debugging practices, my code lives and dies by the Chrome (or other browser) console.
Console.log is one of my code's best friends. In this case, it probably would have helped you because it wouldn't have been able to properly render the malformed JSON in the console. When in doubt, log it out!
I also use the Chrome console to see the exact request that was sent to the server. Often, you can double click that request and open it in a new tab so that you can make the same request repeatedly. This gives you the opportunity to see how the response changes as you change the server-side code.
Good luck.
Why isn't there a stacktrace for either of these lines?
Because the operation is async,and doesnt happen on the "same" stack as your code.When the ajax call returns,the stack in your code has already been "unstacked" a long time ago.
A good explaination of what's happening can be seen here :
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/EventLoop
There is basically,a stack,a heap like other languages, but also a queue of async operations that will have their own stack.
That's why for instance,if you throw an error in a async operation(a setTimeout for instance),you cant try/catch it in the stack that triggered the setTimeout.
The rest is experience.You need to learn that Object.parse (native) refers to JSON.parse.You also need to learn AngularJS api,obviously angular.fromJson method is related to a (de)serialization operation.
You can set your breakpoints in chrome(hit f12 to open up dev tools). Then you can step through your code line by line to see if you missed anything. Also you might want to look up Batarang which is a chrome extension used to specifically debug AngularJS.
Use IDE application to inspect the code for syntax error.
If your application retrieves data from JSON file, use JSON validator to check those json file.
I am having problems finding the solution to two errors on a web site I am building on a Joomla 3.0.2 platform and using the Gantry Framework.
The first error is:
Type issue
'null' is not an object (evaluating 'b.appendChild')
The second error is:
Type issue
'undefined' is not an object (evaluating 'rikgallery_slideshow.jump')
I have never understood how to debug javascript errors, so I would really appreciate some help.
The site can be accessed at: http://lads.ergonomiq.net
If someone can help and needs super user access to the back end, please email me at ali.samii#ergonomiq.net
Thanks
This is meant to simply point you in the right direction, further testing will be required to fully solve your issues.
OK the first error is happening in responsive.js line 66
menu.inject(document.getElement('.menu-block'));
I would console.log(menu, document.getElement('.menu-block')) make sure both contain an element as expected. I am guessing one of those will be null.
Second error
AjaxURL: 'http://lads.ergonomiq.net//index.php?option=com_roksprocket&task=ajax&format=raw&ItemId=101'
is returning unexpected JSON
{"status":"error","message":"Unable to find class for item ","payload":null}
I would test the error and only proceed if you have images in your returned JSON
Line 136 of your home page.
Hope this helps
I have never understood how to debug javascript errors, so I would
really appreciate some help.
If you want to debug JavaScript errors, you should be using FireBug with the FireFox browser. You can get the FireBug Add-on here. You will then be able to find these bugs yourself.
I submitted my addon to the firefox amo directory and it got reviewed and passed, but the reviewer sent me this message:
2) The following error appears in the Error Console. It's fairly easy to
fix.
Error: gBrowser.addProgressListener
was called with a second argument,
which is not supported. See bug
608628. Source File: chrome://browser/content/tabbrowser.xml
Line: 1840
The thing is I have nver touched chrome://browser/content/tabbrowser.xml and dont even know where to find it... so how do I fix this problem?
Thanks!
Sounds like you are calling addProgressListener() somewhere in your code with multiple arguments. It is a single argument function - you can find the documentation here:
https://developer.mozilla.org/en/XUL/tabbrowser#m-addProgressListener
The location chrome://browser/content/tabbrowser.xml is where the function is defined, and line 1840 is the location in the file where the "don't call this function with more than one argument" error is thrown. You can find the file in a check out of the FF source at (I think) browser/base/content/tabbrowser.xml, but you probably don't need to examine it in this case.
That's just a warning about a common mistake. nsIWebProgress.addProgressListener() supports two parameters. However, <tabbrowser> and <browser> elements don't support this second parameter and ignore it (see tabbrowser.addProgressListener()). People were often using aNotifyMask parameter nevertheless without being aware that it doesn't do anything, so this warning has been added to make sure they notice.