I have a scanner that reads qr codes for delivery packages, the problem is that I can’t do the for each, it reads ten, twenty times the same qr code, what I need is that it reads only once, each try to scan again it returns the message already scanned.
I created a block but it didn’t work very well
block I created more does not work
You can store into tinydb each value of the scanned qr. Every time it is scanned, compare with the list stored in tinydb, if it is different, do what you need to do and add this new value in the scan list.
If it’s already on the list, do nothing…
Did You try ? 
You try all your post with solution ???
Please give me a few minutes and you will see that what I say is true !!!
Good Morning. You didn’t understand what I asked: I asked if he ( @Fabio_Alves) had tried to make that tip.
Relax…
For those who are starting this site it has helped me a lot of a Mexican
What I’m going to try to do now is put a button on the screen like the example below, I think it will get better.
I am studying ways to create this extension, and I found this https://editor.appybuilder.com/ maybe I can build the barcode scanner in java the way I want it.
Hi
After scan check if result exists in TinyDB.tags.
If it is not in tag list then store result as tag (not as value).
The extension is here 
I look forward to
