None of those work for various reasons.
This scheme to save does work for a Trak (in this case, to display a LineString with four points (that describe a rectangle).
The JSON coordinates for the Trak are: [[10.22054,-83.59250],[10.22088,-83.59176],[10.22054,-83.59156],[10.22019,-83.59232],[10.22054,-83.59250]]
The code saves a LineString route (or Trak) as a LineString in a TinyDB Tag called trak1. When you run this code, you must set
First, the Trak must be created. Button1.
Then it must be save as a Tag called trak1 using the code in Button2
Then, and only then can it be retrieved using the code in Button3.
To confirm that the trak1 is saved; close the app. Run the program again but do not use Button’s 1 and 2. Use Button3. Do you see the rectangle drawn on the Map?
Can this stuff be saved other ways? Perhaps. This technique saves a Trak in a TinyDB. It is the simplest way I am aware of. My previous post shows how to save and re-display a polygon. Similar code will allow saving of other Map features.
Did you try the code? What happened?