MATLAB: Do I get the error “Unable to access the enumeration constant” in Stateflow R2019a

stateflow

I have a model containing a Stateflow chart, which uses the enumerated type "BasicColors" in a local Stateflow variable with the same name. The enumerated type is defined in a data dictionary.

The model works fine in R2018b. However, when I tried to run the model in R2019a, I got the error:

Unable to access the enumeration constant 'Red' from a variable. Use the enumeration name: 'BasicColors.Red'.
Transition < '[Basic...action}'
>"BasicColors"

The error message is referring to the following statement in a transition condition:

BasicColors == BasicColors.Red

Best Answer

Starting in R2019a, Stateflow will error out when there is a name confict between a local variable name and enum type class identifier.

To distinguish the "BasicColors" variable from the "BasicColors" enumeration, rename the local Stateflow variable to a name that is different from the enum class identifier (for example "MyBasicColor"). The according transition statement will be:

MyBasicColor == BasicColors.Red

Related Solutions

MATLAB: Expecting different input for Stateflow chart

To address this issue in your Stateflow chart, please ensure that the "Use Strong Datatyping with Simulink I/O" setting is checked:

https://www.mathworks.com/help/releases/R2017a/stateflow/ug/specifying-chart-properties.html#zmw57dd0e58419

Our R2019b documentation states that "clearing this check box can produce unpredictable results and is not recommended."

MATLAB: Do I receive a “Error using Stateflow.Clipboard/copy” when I try to update Stateflow library interfaces that contain graphical Stateflow functions that are set to “subchart” in R2017a+

In MATLAB R2017a+, you can copy the content of the sub-charted graphical functions by setting the flag '-depth' to 1. This will copy a sub-charted function and its content all together. Please note that this solution works best if there is not a mix of sub-charted and non-sub-charted graphical functions and or states.

Please refer to the following lines of code below for an example of how to set this flag:

% Find the matching chart.  Get contents.
State = OldChart(iOldChart).find('-isa', 'Stateflow.State', '-depth', 1);
Transition = OldChart(iOldChart).find('-isa', 'Stateflow.Transition', '-depth', 1 );
Junction = OldChart(iOldChart).find('-isa', 'Stateflow.Junction', '-depth', 1);
Note = OldChart(iOldChart).find('-isa', 'Stateflow.Note', '-depth', 1);
Function = OldChart(iOldChart).find('-isa', 'Stateflow.Function', '-depth', 1);
Box = OldChart(iOldChart).find('-isa', 'Stateflow.Box', '-depth', 1);

Another alternative if there are some components that are not getting copied because they are in a different depth is to do the following:

% Find all objects
states = OldChart(iOldChart).find('-isa', 'Stateflow.State');
% Select the objects that are in the same subviewer
states = states(arrayfun(@(x)(x.Subviewer.Id == x.Chart.Id), states));

Then, you should be able to use the "sfclipboard" object to copy and paste the contents of the library.

Best Answer

Related Solutions

MATLAB: Expecting different input for Stateflow chart

MATLAB: Do I receive a “Error using Stateflow.​Clipboard/​copy” when I try to update Stateflow library interfaces that contain graphical Stateflow functions that are set to “subchart” in R2017a+

Related Question

MATLAB: Do I receive a “Error using Stateflow.Clipboard/copy” when I try to update Stateflow library interfaces that contain graphical Stateflow functions that are set to “subchart” in R2017a+