[SCXML-99] Support read-only system variables

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9
• Fix Version/s: 2.0
• Assignee: Ate Douma
• Reporter: Ingmar Kliche
• Created: 10/Dec/08 22:30
• Updated: 09/Apr/15 13:48
• Resolved: 30/Mar/14 19:20

Description

The SCXML WD [1] describes a set of system variables which are read-only for the application. See section 5.5 [2]: "The Data Module maintains a protected portion of the data model containing information that may be useful to applications...."

It may necessary to abstract out the notion of a partitioned root context, just like we have a notion of ordinary context.

The implementation should take into account, that some expression languages support read-only behaviors natively (such as ECMAScript through scope chains), whereas other expression languages (or there implementations resp.) don't.

[1] http://www.w3.org/TR/2008/WD-scxml-20080516/
[2] http://www.w3.org/TR/2008/WD-scxml-20080516/#SystemVariables