1. ARCH-07: Implementing the OpenEdge™ Reference Architecture – Part 2
John Sadd
Progress Fellow and OpenEdge Evangelist

2. Modern Application Architecture
OpenEdge Reference Architecture – a layered view
Separated presentation and integration layers
Users
Enterprise
Services
Presentation Layer
Integration Layer
Common business logic with advanced models
Business Servicing Layer
Data access abstracted from storage
Data Access Layer
Managed
Data Stores
Unmanaged
Data Stores

3. Agenda Introducing the Service Interface Layer
Managing ProDataSet Instances
Context Management
Creating a WebSpeed® User Interface
Additional Topics and Futures
Conclusions

4. SOA – Service Interaction Model
Bind
Invoke
Service
Requestor
Provider
Broker/ Directory
Find /
Details
Publish
Enterprise Services
Bus Task

5. Container-managed Support Services
Security
Transaction Control
Session/Context Management
Client
Side
Fn()
Presentation Container
Service Proxy
Service Interface
Service Container
Order Mgmt
Server
Side …

6. The Service Interface Layer in the Architecture
Users
Enterprise
Services
Presentation Layer
Integration Layer
Service Interface
Business Servicing Layer
Data Access Layer
Managed
Data Stores
Unmanaged
Data Stores

7. Role of the Sample Service Interface Layer
Manages server-side entities
Keeps an in-memory catalog of running instances
Provides standard one-call access to server-side procedures
Provides a single simplified API from client to server

8. The Service Interface Layer
Client
Server
UI Procedure
Business Entity
Data-Access Object
DATASET dsOrder
DATASET dsOrder
DATASET dsOrder
RUN fetchOrder
IN hdsOrder
(. . . ,
OUTPUT
DATASET
dsOrder
BY-REFERENCE)
RUN FetchWhere
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
fetchWhere:
FILL
ATTACH
Client Proxy
Server Gateway
Service Interface

9. (call to server-side gateway)
Client-side SI Proxy
Client proxy
procedure
User interface
procedure
proSIproxy.p
PROC fetchWhere:
RUN proSIgateway.p ON hAppServer
(INPUT “Order”,
INPUT “fetchWhere”…) …
dsOrderWinAdv.w
{dsOrder.i}
{proSIproxyStart.i} …
RUN fetchWhere IN
ghProxySIproc
(INPUT “Order”,
INPUT ttContextDSOrder,
OUTPUT DataSet dsOrder).
(call to server-side gateway)

10. Server-side SI Procedures
(call from client session)
Server service
procedure
Server gateway
procedure
proSIserver.p
DEFINE T-T ttEntity…
FN startEntity:
FN getEntityHandle:
/* entity temp-table lookup */
FN getDAOHandle:
proSIgateway.p
hEntity = getEntityHandle
in hSI.
RUN fetchWhere in hEntity …
(call to Business Entity API)

11. Gateway Procedure API Five standard parameters
Logical entity name
Logical operation name
Context/parameter temp-table for passing any related values back and forth
OUTPUT or INPUT-OUTPUT ProDataSet
Depending on whether ProDataSet definition or values need to be passed in
OUTPUT status for exception handling
Useful default for many operations
Use custom APIs and custom gateway procedures for special operations

12. Agenda Introducing the Service Interface Layer
Managing ProDataSet Instances
Context Management
Creating a WebSpeed® User Interface
Additional Topics and Futures
Conclusions

13. Management of ProDataSet Instances
Which object “owns” the ProDataSet instance on server and client?
ProDataSets can be passed BY-REFERENCE to avoid copying
The caller’s instance is always used, even on OUTPUT
This will be extended in 10.1 to support a “pull” model where the called procedure’s instance is used

14. ProDataSet Instances on OUTPUT
Client
Server
UI Procedure
Business Entity
Data-Access Object
DATASET-
HANDLE
DATASET dsOrder
DATASET dsOrder
DATASET dsOrder
BY-REF
HANDLE
BY-REF
RUN fetchOrder
IN hdsOrder
(. . . ,
OUTPUT
DATASET
dsOrder
BY-REFERENCE)
RUN FetchWhere
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
fetchWhere:
FILL
ATTACH
Client Proxy Procedure
Server Gateway Procedure

15. Agenda Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Creating a WebSpeed® User Interface
Additional Topics and Futures
Conclusions

16. Context Management Basics
Target environment is client to state-less or state-free AppServer
Each interaction is independent
Maintain context between related interactions

17. Passing Context between Client and Server
Context/Parameter temp-table passes context back and forth
Name & Value fields allow flexibility
Context is maintained on the client
Useful for small amounts of data
Also for context used on the client
And for context modified on the client

18. Context Between Client and Server
Business Entity
UI Procedure
DATASET dsOrder
DATASET dsOrder
context/parameter
temp-table
RUN FetchWhere
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
RUN fetchOrder
IN hdsOrder
(. . . ,
OUTPUT
DATASET
dsOrder
BY-REFERENCE)
Server Gateway Procedure
Client Proxy Procedure
WhereString = “…”
NextRowid = 63524

19. Context Maintained on the Server
Hold context in a shared server-side data store
Typically a database table
Useful for context not to pass back and forth
Session context such as language, authorization that does not change
Requires a Context ID passed from the client
GUID support in sample and in 10.1

20. Context Stored on the Server
Client
Business Entity
UI Procedure
DATASET dsOrder
DATASET dsOrder
context/parameter
temp-table
RUN FetchWhere
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
RUN fetchOrder
IN hdsOrder
(. . . ,
OUTPUT
DATASET
dsOrder
BY-REFERENCE)
Server Gateway Procedure
Client Proxy Procedure
ContextID = 95847
95847 English Auth …

21. ProDataSet and Temp-table Context
Store retrieved data in a context table
For WebSpeed or other clients with no ProDataSet support
RAW fields and BLOBS for generic storage
Store successive updates before commit
Allows partial validation on the server
Final update ProDataSet rebuilt from context

22. ProDataSet or Temp-table Data as Context
Server
Client
Business Entity
UI Procedure
DATASET dsOrder
DATASET dsOrder
ContextID = 95847
RUN FetchWhere
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
RUN fetchOrder
IN hdsOrder
(. . . ,
OUTPUT
DATASET
dsOrder
BY-REFERENCE)
“OrderNum = 1”
Server Gateway Procedure
Client Proxy Procedure
95847 Order 1 Line 1
95847 Order 1 Line 1
95847 Order 1 Line 2

23. Agenda Introducing the Service Interface Layer
Managing ProDataSet Instances
Context Management
Creating a WebSpeed® User Interface
Additional Topics and Futures
Conclusions

24. Agenda Introducing the Service Interface Layer
Managing ProDataSet Instances
Context Management
Creating a WebSpeed® User Interface
Additional Topics and Futures
Conclusions

25. White Paper: Using an Unmanaged Data Store
Uses an XML document in place of the database
Alternative Data-Source procedure identifies the document
Custom code populates the ProDataSet
Remaining Business Entity code runs unmodified

26. White Paper: Simple .NET Interface to Business Entities
Code generator creates a XSD file with a DataSet description
This in turn creates a C# class file for the DataSet
C# version of the client proxy runs the same gateway procedure on the AppServer
C# DataSet class file used to build the UI

27. White Paper: Advanced Business Logic
The role of database trigger procedures
One Business Entity accessing another
One Data Access Object accessing another
When to allow direct database access

28. The Sample Implementation and Future Releases
Significant new language extensions planned for 10.1 and beyond
Elements of an OO4GL such as classes
Auditing and other built-in core services
Materials to be revised and extended to describe 10.1 best practices

29. Agenda Introducing the Service Interface Layer
Managing ProDataSet Instances
Context Management
Creating a WebSpeed User Interface
Additional Topics and Futures
Conclusions

30. In Summary Think about and plan for services in your application
Think about which objects control the data
Think about context and other aspects of a stateless application server

31. Questions?

32. Thank you for your time!