Recently I read a query about "What does console.log do" and I read an answer, tried using it and found that despite the answer stating that it outputs to the console in googles browser, I just tried it and I get no output.
I did try this code:
function put(p){
if ( window.console && window.console.log ) {
console.log(p); // console is available
}else{
alert(p);
}
}
BUT... I get neither console output or alert and furthermore .log is a Math property, what gives with that?
Make sure that in the Developer Tools the Filter in the console section is set to All or Logs...
I had a similar experience where I couldn't see any of my console.log output and it was because the console was set to filter on Errors only... All the log entries were there - they just weren't visible.
Bonus marks: you can also Ctrl + Click to select multiple filters (Errors + Logs for example).
Press F12 and look at in Developer Tools: Console. I tried your code just now, works fine for me -- Chrome version 30.0.
Since you're after console logging, not mathematical logarithms, perhaps you could stop going on about there being similarly-named function in the Math object. It's not relevant here whatsoever.
You're also coming across just a little shouty. console.log() works fine, and your question didn't indicate that you knew where to look. This is totally your problem, but I'm trying to help you. I can obviously only go on the information you provide, and I can't say your initial question was written very clearly.
It appears, since the snippet of code you posted works here absolutely fine, that your calling code & containing (which you haven't posted) would be the cause of the problem. You should debug these, to find out what's going wrong.
Do you know how to use the Chrome debugger? Are there any error messages showing in Chrome or on the console?
Test it on a simple page if necessary, to rule out other errors in the page/ or surrounding context breaking it. One common mistakes is declare functions in a jQuery ready handler or similar, and then try & access them globally. Make sure your logging function is actually global (outside any other function(){} or object {} blocks).
Lastly, it's good to have a logging function for portability (I have one myself) but put() is not a good name for it. Naming it consoleLog() or log() would be better.
Had the same issue .
Make sure your using de right path when you try import thing's .
Example whit my issue :
Wrong path ----> ** import normalizedData from 'normalizr'; **
Right path ---> ** import normalizedData from '../schemas/index.js'; **
I had also faced the same problem. Make sure you apply no filter in the console. It worked for me.
Related
I need to go back to home default view on Forge Viewer, after a few times go for searching and follow some tutorials to load extension i have something like this
let res = _viewer.loadExtension('Autodesk.GoHome')
if(res){
_viewer.getExtension('Autodesk.GoHome', (gohome)=>{
gohome.active()
})
It not work for me and have an error like "gohome is not a function" ?. Did i do something wrong ?
You have a race condition problem in your code.
I will not get into details here, but briefly speaking, things like "gohome is not a function" usually means that you use an object before it was fully created/initialized.
Try changing your code into:
_viewer.loadExtension('Autodesk.GoHome').then(
(gohome) => {
gohome.active();
})
This should solve the problem.
I am currently reading Async Javascript by Trevor Burnham. This has been a great book so far.
He talks about this snippet and console.log being 'async' in the Safari and Chrome console. Unfortunately I can't replicate this. Here is the code:
var obj = {};
console.log(obj);
obj.foo = 'bar';
// my outcome: Object{}; 'bar';
// The book outcome: {foo:bar};
If this was async, I would anticipate the outcome to be the books outcome. console.log() is put in the event queue until all code is executed, then it is ran and it would have the bar property.
It appears though it is running synchronously.
Am I running this code wrong? Is console.log actually async?
console.log is not standardized, so the behavior is rather undefined, and can be changed easily from release to release of the developer tools. Your book is likely to be outdated, as might my answer soon.
To our code, it does not make any difference whether console.log is async or not, it does not provide any kind of callback or so; and the values you pass are always referenced and computed at the time you call the function.
We don't really know what happens then (OK, we could, since Firebug, Chrome Devtools and Opera Dragonfly are all open source). The console will need to store the logged values somewhere, and it will display them on the screen. The rendering will happen asynchronously for sure (being throttled to rate-limit updates), as will future interactions with the logged objects in the console (like expanding object properties).
So the console might either clone (serialize) the mutable objects that you did log, or it will store references to them. The first one doesn't work well with deep/large objects. Also, at least the initial rendering in the console will probably show the "current" state of the object, i.e. the one when it got logged - in your example you see Object {}.
However, when you expand the object to inspect its properties further, it is likely that the console will have only stored a reference to your object and its properties, and displaying them now will then show their current (already mutated) state. If you click on the +, you should be able to see the bar property in your example.
Here's a screenshot that was posted in the bug report to explain their "fix":
So, some values might be referenced long after they have been logged, and the evaluation of these is rather lazy ("when needed"). The most famous example of this discrepancy is handled in the question Is Chrome's JavaScript console lazy about evaluating arrays?
A workaround is to make sure to log serialized snapshots of your objects always, e.g. by doing console.log(JSON.stringify(obj)). This will work for non-circular and rather small objects only, though. See also How can I change the default behavior of console.log in Safari?.
The better solution is to use breakpoints for debugging, where the execution completely stops and you can inspect the current values at each point. Use logging only with serialisable and immutable data.
This isn't really an answer to the question, but it might be handy to someone who stumbled on this post, and it was too long to put in a comment:
window.console.logSync = (...args) => {
try {
args = args.map((arg) => JSON.parse(JSON.stringify(arg)));
console.log(...args);
} catch (error) {
console.log('Error trying to console.logSync()', ...args);
}
};
This creates a pseudo-synchronous version of console.log, but with the same caveats as mentioned in the accepted answer.
Since it seems like, at the moment, most browsers' console.log's are asynchronous in some manner, you may want to use a function like this in certain scenarios.
When using console.log:
a = {}; a.a=1;console.log(a);a.b=function(){};
// without b
a = {}; a.a=1;a.a1=1;a.a2=1;a.a3=1;a.a4=1;a.a5=1;a.a6=1;a.a7=1;a.a8=1;console.log(a);a.b=function(){};
// with b, maybe
a = {}; a.a=function(){};console.log(a);a.b=function(){};
// with b
in the first situation the object is simple enough, so console can 'stringify' it then present to you; but in the other situations, a is too 'complicated' to 'stringify' so console will show you the in memory object instead, and yes, when you look at it b has already be attached to a.
When executing a script directly in the console in Chrome, I saw this:
Does anyone know what's the meaning of VM117:2
What does VM stand for ?
It is abbreviation of the phrase Virtual Machine.
In the Chrome JavaScript engine (called V8) each script has its own script ID.
Sometimes V8 has no information about the file name of a script, for example in the case of an eval. So devtools uses the text "VM" concatenated with the script ID as a title for these scripts.
Some sites may fetch many pieces of JavaScript code via XHR and eval it. If a developer wants to see the actual script name for these scripts she can use sourceURL. DevTools parses and uses it for titles, mapping etc.
Thanks to #MRB,
I revisited this problem, and found the solution today,
thanks to https://stackoverflow.com/a/63221101/1818089
queueMicrotask (console.log.bind (console, "Look! No source file info..."));
It will group similar elements, so make sure you add a unique identifier to each log line to be able to see all data.
Demonstrated in the following example.
Instead of
data = ["Apple","Mango","Grapes"];
for(i=0;i<10;i++){
queueMicrotask (console.log.bind (console, " info..."+i));
}
use
data = ["Apple","Mango","Grapes"];
for(i=0;i<data.length;i++){
queueMicrotask (console.log.bind (console, " info..."+i));
}
A better way would be to make a console.print function that does so and call it instead of console.log as pointed out in https://stackoverflow.com/a/64444083/1818089
// console.print: console.log without filename/line number
console.print = function (...args) {
queueMicrotask (console.log.bind (console, ...args));
}
Beware of the grouping problem mentioned above.
Alright dudes... I have a problem that is looking for an answer more specific than the seemingly obvious solution.
I have a block of code that I want to execute directly after a url is known to be valid. What I mean by 'valid' is that the program has checked to see if that filepath actually exists. This could be accomplished by a COMPLETE listener, because after all, a loader couldn't finish loading its content if the referenced file didn't exist, but I want it to happen before any of the bytes begin to get sucked in. I have also tried the HTTPS_STATUS event, with a conditional saying "if the status is this [some non-error status number], then run this block of code." This would have worked great, except that different environments produce different network codes, and some even can't distinguish between errors and non-errors, just returning 0's no matter what. Because of this, I can't write a conditional that works no matter what browser....
So, anyone got any ideas?!?!?!?!
If this doesn't work post your code.
myUrlLoader.addEventListener(Event.OPEN, openHandler);
//Dispatched when the download operation commences following a call to the URLLoader.load() method.
I have installed the sfErrorNotifierPlugin. When both options reportErrors/reportPHPErrors reportPHPWarnings/reportWarnings are set to false, everything is ok. But I want to catch PHP exceptions and warnings to receive E-mails, but then all my tasks fail, including clear-cache. After few hours of tests I'm 100% sure that the problem is with set_exception_handler/set_error_handler.
There's a similar question:
sfErrorNotifierPlugin on symfony task but the author there is having problems with a custom task. In my case, even built-in tasks fail.
I haven't used sfErrorNotifierPlugin, but I have run into 'The “default” context does not exist.' messages before. It happens when a call is made to sfContext::getInstance() and the context simply doesn't exist. I've had this happen a lot from within custom tasks. One solution is to add sfContext::createInstance() before the call to sfContext::getInstance(). This will ensure that a context exists.
There's an interesting blog post on 'Why sfContext::getInstance() is bad' that goes into more detail - http://webmozarts.com/2009/07/01/why-sfcontextgetinstance-is-bad/
Well, the problem could not be solved this way, unfortunately. Using sfErrorNotifierPlugin, I have enabled reporting PHP warning/errors (apart from symfony exceptions) and this resulted in huge problems, e.g. built-in tasks such as clear-cache failed.
The solution I chose was to load the plugin only in non-task mode (project configuration class):
public function setup()
{
$this->enableAllPluginsExcept('sfPropelPlugin');
if ('cli' == php_sapi_name()) $this->disablePlugins('sfErrorNotifierPlugin');
}
WHen a task is executed, everything works normally. When an app is fired from the browser, emails are sent when exception/warning occurs (maybe someone will find it useful).
Arms has explained the problem correctly. But usually context does not exist when executing backend/maintenance tasks on the console. And it is easier if you handle the condition yourself.
Check, if you really need the context?
If you do, what exactly do you need it for?
Sometimes you only want a user to populate a created_by field. You can work around by hard-coding a user ID.
If you want to do something more integrated, create a page (which will have a context) and trigger the task from there.
you can test the existance of the instance before doing something inside a class. Like:
if(sfContext::hasInstance())
$this->microsite_id = sfContext::getInstance()->getUser()->getAttribute('active_microsite');
I've been experiencing the same problem using the plugin sfErrorNotifier.
In my specific case, I noticed a warning was raised:
Warning: ob_start(): function '' not found or invalid function name in /var/www/ncsoft_qa/lib/vendor/symfony/lib/config/sfApplicationConfiguration.class.php on line 155
Notice: ob_start(): failed to create buffer in /var/www/ncsoft_qa/lib/vendor/symfony/lib/config/sfApplicationConfiguration.class.php on line 155
So, checking the file: sfApplicationConfiguration.class.php class, line 155,
I've replaced the ' ' for a null, then the warnings disappears, and also the error!
ob_start(sfConfig::get('sf_compressed') ? 'ob_gzhandler' : ''); bad
ob_start(sfConfig::get('sf_compressed') ? 'ob_gzhandler' : null); good