enter image description here
I get the followingg Toast outputs
CODE IS RUNNING
and
s
So my code is running but my_shop is not being changed?
Your code is working fine, I think you are a bit confused as to how the code above actually works. the onDataChanged method is triggered/called asynchronously ONLY when the data in the database/server changes, hence the toast-'CODE IS RUNNING' is displayed correctly.
But you are checking the my_shop.getShop_name() outside the onDataChanged method, hence by the time the program counter reaches the second toast, the onDataChanged method hasn't been called yet. The shop_name is still the one that you assigned in line 2 which is what is displayed on the Toast! (which is why you think the code isn't running properly even if it is working fine!)
I would suggest you read more about event listeners in general to get a better idea abouut this behaviour! you can read more about the API in the firebase documentation: https://firebase.google.com/docs/database/android/read-and-write
Related
I'm repairing my friend's code and got confused.
My friend wants to fetch entered text (in EditText). Seems easy, right? Well, it is but instead of user input, he gets this warning/error:
To be honest I'm not sure how to fix it. He is coding in Kotlin (Android 10).
Activity that contains EditText:
And XML:
This is how it looks when debugging:
The app started working just fine after running "File -> invalidate Cashes/Restart" option, I just don't understand where this warning came from and how to fix it because the error remained unchanged (even though the app works). Do you have an idea how to solve it?
All the best!
fyi lambda expression like setOnClickListener from kotlin is not debuggable, see here.
if you want to debug variables inside setOnClickListener you should use the normal one e.g. setOnClickListener(object: View.OnClickListener {..})
sometimes there will be problem in auto generated binding files, if so it will be solved after invalidate cache and restart ide. sometimes the warning/error show but the project and complied without errors. so no need to worry about that. for next time post the code as code not screen shots.
I understand that the question is regarding evaluating expression, but there is a way you can read variables from your debugger console, even if you're inside an anonymous callback. I found it helpful sometimes. Here are the steps:
First enter debugger mode inside of your anonymous callback,
In your debugger console, look at the right side for "Frames"
Within Frames under , you'll see stack of function execution first top one on the list is the latest:
Click on row(s) below the latest function, until you find an instance of your activity AddInformationActivity. You will see the activity instance on the right side window under Variables. Don't go as far as selecting functions browned out, because those are from internal libraries.
When you see you AddInformationActivity instance, you can expand it and see its variables.
Hope that helps!
It's not a beautiful way, but if you create a method like this:
private fun debug() {
println()
}
and add a breakpoint on the println() it'll capture the activity.
(Don't use TODO as it'll crash the app with a NotImplementedError once called.)
I have this method now in my code all the time to call it whenever I need it.
I know, that question is old, but I just stumbled over it and needed a way.
I am developing an Android app (It doesn't matter though) using RxJava2, and in some singleton there are some PublishProcessors.
And there are a lot of .onNext() calls on these PublishProcessors all over the project.
Now in order to debug, I need to know, on every .onNext() called, which line in my project invoked this .onNext().
Is there a way in RxJava(2) that I can achieve this?
I think you can use Frames tab in Debug menu.
For example, in this case, MainActivity line 18 trigger onNext
Ah, thanks to #PhanVanLinh, I found a solution that worked for me.
(Actually it has pretty much nothing to do with RxJava...)
You just need to print the stacktrace using Thread.currentThread.stackTrace and print it to your own string inside doOnNext(), but remember to do it before .observeOn() so that the thread won't switch, it must stay at the original thread that called .onNext(), otherwise you won't get meaningful information.
Then you will know which line that called .onNext().
I'm starting to approach this wonderful world of Realm. I'm very happy of the results I'm getting and now I have one question to submit.
In my android app I've got a Fragment that displays data retrieved from Realm. The query condition is that the time this data refers to is in between the beginning and the end of today.
RealmResults<Appointment> results = realm
.where(MyObject.class)
.between("begin", rangeBegin, rangeEnd)
.between("end", rangeBegin, rangeEnd)
.findAllSorted("begin", Sort.ASCENDING);
This query is executed in the onStart() method helping me to exploit the live-update feature, which indeed works very well.
I've also added listeners for changes in order to optimize UI updates.
Now the question is: how does this live-update behave if the time conditions change? (Imagine I keep the app opened for more than one day without touching it or simply I keep the app opened for minutes around midnight)
From what I've seen it seems to do the same query done the very first time onStart() was executed.
Is there a way to have also live-updating query or should I re-run that query somewhere else outside onStart()?
Thank you in advance
Now the question is: how does this live-update behave if the time conditions change? (Imagine I keep the app opened for more than one day without touching it or simply I keep the app opened for minutes around midnight)
The query is pretty constant after you've set it up, so you'd need to execute a new query with different parameters for rangeStart and rangeEnd, and replace your other results.
This query is executed in the onStart() method helping me to exploit the live-update feature, which indeed works very well. I've also added listeners for changes in order to optimize UI updates.
Personally I'd advise to put the query in onCreateView() instead, and the Realm lifecycle management to onCreateView() and onDestroyView().
Also, you can avoid manually assigning RealmChangeListeners for displaying lists if you use RealmRecyclerViewAdapter (adapters 1.3.0 works with realm 1.2.0).
If you use RealmRecyclerViewAdapter, then just call adapter.updateData(newResults); and it'll update the view as needed.
Expanding the functionality of an under development app, I need to show to the user a progress notification dialog. Problem is, I cannot get it done right. Furthermore, I cannot dismiss this notifier properly. Have tried with a clock and a variable set to e.g. "5000ms" and then to "0", without any lack.
What I need to achieve is the following functionality:
a. Check if the tag "storeparsedData" is in a TinyDB, populated with the fetched JSON data. I have this done, following #Taifun advice in my relative question.
b. If the tag is not there (empty list), do a getWeb.gotText block to get the JSON data (this is done with procedure "getWebData". This functions right, but takes a while about 1'35'' or more, so need to show something to the user.
c. While fetching JSON data form web, need to show a "ShowProgressDialog" notifier to the user, so I can cope with the smartphone being seemingly freeze.
d. If the tag "storeparseData" is populated with fetched JSON data, dismiss the notifier.
Have tried the following coding, without relevant success:
Can someone help me out, to achieve this functionality in this app? A blocks code or something to follow and learn, will be awesome.
Thank you all in advance for your answers.
[Edit1]
After #Taifun suggestions, the functionality in question seems to be working, but there is a problem."ShowProgressDialog" block never fires, neither on device or companion. Also where should block "DismissProgressDialog" be attached to disable notifier upon JSON data received?
Here is the reviewed blocks code, for checking stored tags in TinyDB. "ShowProgressDialog" never fires as it should. Are there any suggestion for this issue?
Here is the blocks code for the getWeb function to get the JSON data:
Please advise, with a block code if applicable.Thank you all.
Your progressNotifier.AfterChoosing event never will fire, because that event only fires after choosing something from a Notifier.ShowChooseDialog block, but not for Notifier.ShowMessageDialog blocks. Therefore use a Notifier.ShowChooseDialog block instead and set the second button in that block to empty string.
Your while loop will freeeze your app, as you already realized... You do not need the Clock.Timer event at all to check if your data is there.
Just do it like this: after having received your data in the Web.GotText event and having stored the data in TinyDB, then dismiss the progress dialog and display the message "Database is ready".
Update: Instead of storing your list n times inside the for each in list loop, you should store it only once after the for each in list loop is finished... Same for the DismissProgressDialog and ShowAlert block...
What is the purpose of that join block? You might want to remove it...
Here is the link of the Minesweeper project on codeproject.com.
I just wanted to ask one thing here. I completely understood the logic and algorithm this guy used, but when he called the showMineField() method inside startNewGame() method , he called it after createMineField(). I am really confused! Shouldn't the layout be set before setting up mines and handling the user click events? But the code seems to work fine. If I just call showMineField() inside startNewGame() , it gives me NullPointerException.
This is because you cannot show a mine field before creating all the objects.
It is like trying to run without legs. If you call showMineField() that is using objects that have not been initialized. Thats why you are recieving a NUllPointerException. Nullpointer is throws when a method is trying to be call on an object that has not been created yet. createminefield() initialzes everything so that nullpointer is not thrown