isDerived property of a UML attribute - API gen behaviour

[onthebreeze]

In many cases there are some fields in an API response that are determined by the back end and, although they are visible in a GET, the cannot be created or modified (in POSt/PUT/PATCH). Examples are things like "status" (of back end processing) or "versionID" (automatically updated), etc.

Suggest we use the "isDerived" property of a starUML attribute to drive Open API generation. when an attribute is marked with "isDerived" then

• it appears in GET operation responses
• it is not in the data model of POST/PATCH/PUT operations.

[kshychko]

After discussion it has been agreed to use isReadOnly property, as it aligns with OpenAPI readOnly flag for properties.