How to define guard in state transition (succession / successionAsUsage)

[dvojtise]

For my model I need to use state machines.

How to specify the guards on the transition ? (statemachine without transition guard are useless ...)

In sysml v2, it seems that we can use accept and if as ways to specify the condition required to trigger the transition

I tried importing from textual notation (using the reference example https://github.com/Systems-Modeling/SysML-v2-Release/blob/master/sysml/src/training/25.%20Transitions/Transition%20Actions.sysml , I use the same kind of transition definitions in my model )

but on this small example I have several import issue.
among them : neither the if nor the accept are imported (other error: the do that doesn't work too, and the target isn't set)
and I can't find a way to fix it manually using the graphical ui of syson

Note: I noticed that the example doesn't create the transition in the same way SysON does it ( import from text creates a SuccessionAsUsage, while UI creates a Succession)

but I can't find a way to add the accept/if/do on the transition even using transition created using the UI

Any idea of workaround ?

tested on fresh docker compose up on syson v2025.1.5 (the v2025.1.6 fails to connect to syside and all imports fails)

log error when importing the Transition%20Actions.sysml example:

app-1       | [Error] Error while setting attribute kind with value "accept" : The value 'accept' is not a valid enumerator of 'TransitionFeatureKind'
app-1       | [Error] Error while setting attribute kind with value "accept" : The value 'accept' is not a valid enumerator of 'TransitionFeatureKind'
app-1       | [Error] Error while setting attribute kind with value "if" : The value 'if' is not a valid enumerator of 'TransitionFeatureKind'
app-1       | [Error] Unable to find containment reference in [FeatureChainExpression] null::<OwningMembership>::<Package>::<OwningMembership>::<StateUsage>::<FeatureMembership>::<TransitionUsage>::<TransitionFeatureMembership>::<FeatureChainExpression> with reference operands for holding {"$type":"FeatureReferenceExpression","expression":{"$type":"Membership","targetRef":{"$type":"FeatureReference","$cstNode":{"text":"operatingVehicle","stack":["FeatureReference","FeatureReferenceMember"]},"text":"operatingVehicle","reference":"Transition Actions::vehicleStates::operatingVehicle","parts":["Transition Actions::vehicleStates::operatingVehicle"]},"$cstNode":{"text":"operatingVehicle","stack":["FeatureReferenceMember","FeatureReferenceExpression"]},"isAlias":false,"elements":[],"$meta":{"elementId":121,"qualifiedName":""}},"$cstNode":{"text":"operatingVehicle","stack":["BaseExpression","PrimaryExpression"]},"isNonunique":false,"isOrdered":false,"heritage":[],"isSufficient":false,"typeRelationships":[],"children":[],"prefixes":[],"$meta":{"elementId":120,"qualifiedName":""}}
app-1       | [Error] The following element has not be handled in the ast key operands value {"$type":"FeatureReferenceExpression","expression":{"$type":"Membership","targetRef":{"$type":"FeatureReference","$cstNode":{"text":"operatingVehicle","stack":["FeatureReference","FeatureReferenceMember"]},"text":"operatingVehicle","reference":"Transition Actions::vehicleStates::operatingVehicle","parts":["Transition Actions::vehicleStates::operatingVehicle"]},"$cstNode":{"text":"operatingVehicle","stack":["FeatureReferenceMember","FeatureReferenceExpression"]},"isAlias":false,"elements":[],"$meta":{"elementId":121,"qualifiedName":""}},"$cstNode":{"text":"operatingVehicle","stack":["BaseExpression","PrimaryExpression"]},"isNonunique":false,"isOrdered":false,"heritage":[],"isSufficient":false,"typeRelationships":[],"children":[],"prefixes":[],"$meta":{"elementId":120,"qualifiedName":""}}
app-1       | [Error] Error while setting attribute kind with value "do" : The value 'do' is not a valid enumerator of 'TransitionFeatureKind'
app-1       | [Error] Error while setting attribute kind with value "accept" : The value 'accept' is not a valid enumerator of 'TransitionFeatureKind'
app-1       | [Error] [Unable to resolve following proxy] Owner '[Membership] 'Transition Actions'::vehicleStates::<FeatureMembership>::<TransitionUsage>::<TransitionFeatureMembership>::<FeatureChainExpression>::<Membership>' to qualifiedName 'brakePedalDepressed' for reference 'memberElement'

[AxelRICHARD]

Hello,

Thank you for using SysON and give us feedback, it helps us a lot!

We are currently working on import from textual SysMLv2 and export to textual SysMLv2 modules in SysON to improve them and fixes unhandled cases.
You are probably in one of those cases.

So there is no workaround, just wait for improved versions or support SysON developments!

Regards,

[dvojtise]

I understand the issue about import/export to/from textual notation,

but using the graphical UI ( ie. not speaking about textual notation), is there a way to create the if and accept expressions (for example using the explorer ?)

[AxelRICHARD]

No, unfortunately, this is not possible yet in SysON.
We will try to implement it in the next releases.

Regards,