Problem with selecting element from list to list of list

Hi everyone, it's my first time her for writing but I read you a lot. I don't understand something, I certainly forget something somewhere...

Why the name of the list can't be a attribute ?

Thanks by advance for your help :wink:


if you click on the red cross you will see the error:

you cannot use a variable to define other one.

You can work around this by making a value procedure named graph instead of that global variable named graph.

Use a call to the value procedure wherever you would have used the value of the graph global variable.

1 Like

hi there, thanks for your help. This solution looks fine in the App Inventor. I have still an issue with my app.

That is the thing : I store value in CSV file by text export, the result is OK, the file is correctly implement but I've difficulties to extract this values to store in some lists to use as a graph.

Can you help me to found is everything is correct please ?

Best regards,


  1. Show the raw output of graph
  2. Remove all the extraOptions and css, do you get a graph ?

Can you show what "global Journal" has?

Here you have the screens with and without ExtraOption and no CSS.
What do you think ? Is it from the graph or from the list ?

Thanks for you help :slight_smile:

Ramon, thanks for your time. That's is the "Journal" values.

Looks like the data to begin with...

Please show your raw output from graph (preferably as text (not an image)

I think I get you, maybe not...
The graph should show a graph bar with this values for exemple (from the CSV file) :
19/03/2024 13:18:03, ouverture
19/03/2024 13:18:05, accord
19/03/2024 13:18:06, Cuisiner
19/03/2024 13:18:08, Cuisiner
19/03/2024 13:18:09, Manger
19/03/2024 13:18:10, Envoyer un message
19/03/2024 13:18:11, Cuisiner
19/03/2024 13:18:14, Manger

I count the number of subject by name and I would like to use it as graphs.
Here the column is : Name, Number, Color.

The date (e.g. 19/03/2024) would need to be a string and not a date/dateNumber.
(different for each record, so won't work if all the dates are the same)

The time (e.g. 13:18:03,) would need to be a number
(currently, with the comma at the end as well, the times are strings, so won't work)

Thanks for you help and time TIMAI2, I understand but I don't need the date or time in my graph and I don't use it. It's just a record information.

After reading the file, I count the number of time the expression is and I store this value in a list with his name and a random color.

You are initializing that variable like a string:


and setting to a value...or you manage it like a list...or you remove the "length of list"..

So why did you show this as your input data for the pie chart.

Show your input arrayData for the pie chart please

Maybe I was not clear enough...the problem is not only the initialization that, if you are handling a list must be like an empty list, it is also when setting a value...

you have to "add item" to the list or "insert list item"....because if you only set a have not a list...

EDIT: Maybe this will clarify what I'm saying to you.

See this from the documentation for the extension:

Your arrayTable for a pie chart needs to have this format:

          ['Task', 'Hours per Day'],
          ['Work',     11],
          ['Eat',      2],
          ['Commute',  2],
          ['Watch TV', 2],
          ['Sleep',    7]