1 / 22

Increasing the Flexibility of Modelling Tools via Constraint-Based Specification

Increasing the Flexibility of Modelling Tools via Constraint-Based Specification. Philip Gray & Ray Welland Computing Science Dept University of Glasgow, Scotland {pdg, ray}@dcs.gla.ac.uk www.dcs.gla.ac.uk/{~pdg, ~ray}. What this presentation is about.

wyatt-berry
Download Presentation

Increasing the Flexibility of Modelling Tools via Constraint-Based Specification

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Increasing the Flexibility of Modelling Tools via Constraint-Based Specification Philip Gray & Ray Welland Computing Science Dept University of Glasgow, Scotland {pdg, ray}@dcs.gla.ac.uk www.dcs.gla.ac.uk/{~pdg, ~ray}

  2. What this presentation is about • degree of configuration of most CASE tools is • limited • ad hoc (or at least not principled) • metaCASE offers the possibility of principled and systematic • development of new or evolving tools • customisation of existing (metaCASE generated) tools

  3. What this presentation is about • we are developing a generic constraint-based approach to tool specification in a metaCASE environment that offers • wide range of modelling techniques • configuration • of the modelling technique • of editing tool • of design support

  4. Intrinsic vs Extrinsic Constraints Intrinsic Constraint - “v2 must be = v1 * 2” v2 v1 v1 * 2 value updated when v1 changes 2 Extrinsic Constraint - “v2 should be = v1 * 2” v1 2 v2 ? checked by constraint manager; different actions possible the constraint v2 = v1 * 2

  5. Varieties of specification constraints

  6. Varieties of specification constraints

  7. Hard vs soft constraints • hard constraint - prohibits all actions that would violate the constraint • soft constraint - actions that violate constraints are possible during diagram construction

  8. Levels of specification in a modelling tool • relationship levelboxes and lines (an uninterpreted graph) • representation levelthe semantics of the graph augmented to represent a software model • presentation levelthe appearance and interactive behaviour of the augmented graph

  9. Using constraints to specify a modelling technique • examples of constraints to create a DFD modelling tool • relationship: must be fully connected graph • representation: must have a least one external source • presentation: external entities are displayed as ellipses

  10. Other things we can do with constraints • style rules • critiquing - like Argo UML editor • guidelines • automated “to do” list • automated or semi-automated proof of assertions over constraint set • “Are the constraints consistent?”

  11. DECS • Design Editor Constraint System • based on • Napier 88-based prototype (Serrano 97) • Representer System (Gray 96) • consists of • model editing tools • tool builder • constraint specification language

  12. DECS: the (target) modelling tool Target Tool AugmentedGraph GraphView

  13. DECS: the (target) modelling tool Target Tool Blah blah Constraints Blah blah Blah blah Blah blah ConstraintManager AugmentedGraph GraphView

  14. DECS: the modelling tool generator Tool Generator Blah blah Target Tool Blah blah Constraints Blah blah Blah blah ConstraintManager AugmentedGraph GraphView

  15. DECS: the modelling tool generator modellingtechnique classes Tool Generator tool specification( inVCt ) Blah blah Target Tool Blah blah Constraints Blah blah Blah blah ConstraintManager AugmentedGraph GraphView

  16. Constraint specification • condition • scope • action parameters • critiquing message • optionally • default value • corrective action parameters

  17. VCt : the DECS specification language • declarative language for describing modelling techniques • “There must be a least one external entity which provides input to the system” $e: ExternalEntity ·e ÎExternals(dfd)Ù $f: DataFlow·fÎDataFlows(dfd)Ù (source(f) = e)

  18. State of our work • Prototype DECS run-time system • implemented in Java • based on GEF • limited techniques • constraints semi-automatically generated from XML specification • limited run-time constraint editor

  19. State of our work • current work • VCt Java translator • VPBE system for constraint generation • addition of configurable augmented graph for run-time technique configuration • enhancement of presentation level

  20. Future developments • investigate specification methods • VCt : is it usable? • dynamic specification • support • abstraction/explosion • design history • automatic verification • enhance range of corrective & supportive actions

  21. The missing bit (Section 2.3) • Typically, design-time constraints are used to generate code that will prescribe the way in which the user can interact with the generated tool.

More Related