Implementing the
OpenEdge Reference
Architecture
John Sadd
Progress Fellow and OpenEdge Evangelist
Agenda





Simplify your business


2
Introducing the OERA Implementation
Business Entities and Data Access Objects
Business Logic Issues
Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Conclusions
© 2005 Progress Software Corporation
Implementing the OERA
Modern Application Architecture
OpenEdge Reference Architecture – a layered view
Enterprise
Services
Users
Separated presentation
and integration layers
Presentation Layer
Simplify your business
Common business
logic with
advanced models
Data access
abstracted from
storage
3
© 2005 Progress Software Corporation
Integration Layer
Business Servicing Layer
Data Access Layer
Managed
Data Stores
Unmanaged
Data Stores
Implementing the OERA
Implementing the OERA:
What are the goals?
Objectives


Simplify your business

4
To provide an understanding of the
OpenEdge Reference Architecture by
describing a sample implementation
To help you understand best practices for
using OpenEdge features
To motivate architects & lead developers
to think about applying the OERA to their
own projects
© 2005 Progress Software Corporation
Implementing the OERA
Implementing the OERA:
What are non-goals?



Simplify your business

Not a new framework
Not intended to be comprehensive or to
cover all application use cases
Not intended to be commercialized
Not intended to be used without changes,
extensions, and understanding
5
© 2005 Progress Software Corporation
Implementing the OERA
How Should You Use It?


Simplify your business

6
Use it to learn OERA concepts more
deeply
Use it to learn how best to use OpenEdge
4GL constructs and other features
Consider it as a potentially useful
starting point for OpenEdge 10 application
development
© 2005 Progress Software Corporation
Implementing the OERA
Who Is It For?

Architects and Lead Developers with
– A strong knowledge of Progress 4GL
development
– Familiarity with key OpenEdge 10 features
– Access to the latest release
– Plans
Simplify your business


7
To re-implement an application, or application
modules
For a new development project
© 2005 Progress Software Corporation
Implementing the OERA
What are the current
OERI white papers?
Simplify your business
1. Introduction
2. Business Entities and Data Access Objects
3. The Service Interface Layer
4. Using Advanced ProDataSet Language
Features
5. Using an Unmanaged Data Store
6. Building a .NET Interface to Business Entities
8
© 2005 Progress Software Corporation
Implementing the OERA
What additional papers are planned?
Simplify your business
7. Advanced Business Logic Issues
8. Context Management
9. Building a WebSpeed User Interface
10. Auditing
11…
9
© 2005 Progress Software Corporation
Implementing the OERA
What is in the sample implementation
code base?

Templates directory
– Template procedures for BE’s, DAO’s etc.

Support directory
– Supporting supers & other procedures

Samples directory
Simplify your business
– Code samples from the papers
– These use sports2000 but there is nothing
database-specific about any sample code
10
© 2005 Progress Software Corporation
Implementing the OERA
Where do I find it?

The white papers and sample code are on
the PSDN website at:
– psdn.progress.com/library/product_info/
oera/index.ssp

Simplify your business


11
There will be ongoing updates
Second phase of 10.0 papers by Exchange
Later material will describe best practices
for using OE 10.1 and its OO4GL features
© 2005 Progress Software Corporation
Implementing the OERA
Simplify your business
12
© 2005 Progress Software Corporation
Implementing the OERA
Agenda






Simplify your business

13
Introducing the OERA Implementation
Business Entities and Data Access Objects
Business Logic Issues
Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Conclusions
© 2005 Progress Software Corporation
Implementing the OERA
The Business Entity and Data
Access Object in the OERA
Enterprise
Services
Users
Presentation Layer
Business
Entity
Simplify your business
Data
Access
Object
Business Servicing Layer
Data Access Layer
Managed
Data Stores
14
© 2005 Progress Software Corporation
Integration Layer
Unmanaged
Data Stores
Implementing the OERA
Business Entities and
Data Access Objects


The Business Entity manages the logical,
internal view of application data
The Data Access Object manages the
physical data store
Simplify your business
– It also handles the mapping to the logic
view of the data
15
© 2005 Progress Software Corporation
Implementing the OERA
Business Entities

The Business Entity manages the logical,
internal view of application data
Simplify your business
– Data for the user interface and other
application layers
– Business logic written against these logical
definitions
– Data best represented as ProDataSets and
their temp-tables

16
The Business Entity is the core of the value
of building applications in OpenEdge
© 2005 Progress Software Corporation
Implementing the OERA
Data Access Objects

The Data Access Object manages the
physical data store
Simplify your business
– It understands the schema or other
description of the physical data
– It translates between this and the
application’s logical view of the data
– All references to the physical data store
should be confined to the Data Access
Object
17
© 2005 Progress Software Corporation
Implementing the OERA
Basic goals of these two object types



Simplify your business


18
Keep the application logic unaware of and
independent of the physical data storage
Keep the Business Entities independent of
the UI and other layers
Define well-managed APIs to communicate
between layers
Build business objects according to welldefined templates and standards
Provide for maximum flexibility and
maintainability
© 2005 Progress Software Corporation
Implementing the OERA
The ProDataSet as a building block
ProDataSet
Data-Source1
Query…
Database
Customer
Lift Line Skiing
Urpon Frisbee
Hoops Croquet
Q1 for
Customer
Field Map
CustNum
Name
Contact
CustomerTT
1 Lift Line Skiing
2 Urpon Frisbee
3 Hoops Croquet
Order
1
2
3
53
81
66
Data-Relation1
01/01/93
01/04/93
01/04/93
Data-Source2
Query…
Q2 for
Order
Field Map
OrderNum
CustNum
OrderDate
OrderTT
6
36
79
1
1
1
01/05/93
01/19/93
02/10/93
Event Logic
Simplify your business
Dataset:Before-fill
Buffer:Before-fill
Before-row-fill
Row-Add
Row-Delete
…
19
© 2005 Progress Software Corporation
Implementing the OERA
Constructing the objects –
temp-table definitions

Define temp-tables for logical data
definitions
– Each temp-table in its own include file
DEFINE TEMP-TABLE eOrder
etOrder.i
FIELD OrderNum…
DEFINE TEMP-TABLE eOrderLine
FIELD OrderNum…
etOrderLine.i
Simplify your business
FIELD LineNum…
20
© 2005 Progress Software Corporation
Implementing the OERA
Temp-table Definitions


These temp-tables are the internal view of
the data
Benefits:
Simplify your business
– Separate physical schema from logical
– Separate server database connection from
business logic
– Allow a body of related data to be passed
as a parameter (typically as part of a
ProDataSet)
– Allow a transaction scope independent of
the database
21
© 2005 Progress Software Corporation
Implementing the OERA
Guidelines for temp-table definitions
Use Temp-DB and Temp-DB Maintenance Tool

Prefix table name with e
– For example




eCustomer
Prefix include files with et

– etCustomer.i
Simplify your business


Rename fields for
consistency or
comprehensibility
Remove unwanted:
– Fields
– Indexes
22
© 2005 Progress Software Corporation

Add other joined DB fields
Add calculated fields that might
be required for ease of use
Add BEFORE-TABLE to end of
definition when tracking
changes
Don’t use LIKE syntax
– Temp-table LIKE databasetable
– Field LIKE database-field
Implementing the OERA
Sample: etCustomer.i
Simplify your business
•TEMP-DB Maintenance Tool
added in 10.0B Release can help
maintain include files
23
© 2005 Progress Software Corporation
Implementing the OERA
One Temp-Table include file
for each temp-table
Code – samples\etOrder.i, etOrderLine, etItem
/* Include file etOrder.i -- temp-table for Order DataSet */
Simplify your business
DEFINE TEMP-TABLE eOrder BEFORE-TABLE eOrderBefore
FIELD
Ordernum
AS INTEGER
/* Include
file etOrderline.i
*/ LABEL "Order Num" FORMAT "zzzzzzzzz9" INITIAL "0"
FIELD
CustNum
AS INTEGER
LABELBEFORE-TABLE
"Cust Num" FORMAT
">>>>9" INITIAL "0"
DEFINE
TEMP-TABLE
eOrderLine
eOrderLineBefore
FIELD
OrderDate
ASAS
DATE
LABELLABEL
"Ordered"
FORMAT
"99/99/99""zzzzzzzzz9"
INITIAL "TODAY"
FIELD
Ordernum
INTEGER
"Order
Num" FORMAT
INITIAL "0"
FIELD
ShipDate
ASAS
DATE
LABELLABEL
"Shipped"
"99/99/9999"
FIELD
Linenum
INTEGER
"LineFORMAT
Num" FORMAT
">>9" INITIAL "0"
FIELD
PromiseDate
ASINTEGER
DATE LABEL
"Promised"
FORMAT
"99/99/99“
FIELD
Itemnum AS
LABEL
"Item Num"
FORMAT
"zzzzzzzzz9" INITIAL "0"
…
…
/* Include file etItem.i */
DEFINE TEMP-TABLE eItem BEFORE-TABLE eItemBefore
FIELD Itemnum AS INTEGER LABEL "Item Num" FORMAT "zzzzzzzzz9" INITIAL "0"
FIELD ItemName AS CHARACTER LABEL "Item Name" FORMAT "x(25)"
…
BEFORE-TABLE tracks changes!
24
© 2005 Progress Software Corporation
Implementing the OERA
Constructing the objects –
Data-Source objects

Build Data-Source object procedure
– Each maps a temp-table to its physical
data
DEFINE DATA-SOURCE srcOrder
etOrder.i
FOR QUERY qOrder.
sceOrder.p
ATTACH-DATA-SOURCE()
etOrderLine.i
DEFINE DATA-SOURCE srcOrderLine
sceOrderLine.p
FOR BUFFER OrderLine.
Simplify your business
ATTACH-DATA-SOURCE()
Application Database
25
© 2005 Progress Software Corporation
Implementing the OERA
Constructing the objects –
ProDataSet definitions

Define ProDataSets for sets of related data
– Each is the basis for a Business Entity
DEFINE DATASET dsOrder
FOR eOrder, eOrderline…
dsOrder.i
etOrder.i
Simplify your business
etOrderLine.i
26
© 2005 Progress Software Corporation
Implementing the OERA
Building the ProDataSet include file
Code sample: dsOrder.i – from template dsDataSet.i
/* dsOrder.i -- ProDataSet definition for dsOrder. */
/* This is the signal that the include file reference is in an AppBuilder
window. Define WINDOW-NAME therefore for all AppBuilder procedures, since
the AppBuilder includes the temp-table includes on its own. */
&IF DEFINED(WINDOW-NAME) = 0 &THEN
{etOrder.i}
 Temp-tables defined and included separately
{etOrderLine.i}
 WINDOW-NAME preprocessor for the
{etItem.i}
AppBuilder
&ENDIF
Simplify your business
DEFINE DATASET dsOrder FOR eOrder,eOrderLine,eItem
DATA-RELATION OrderLine FOR eOrder,eOrderLine
RELATION-FIELDS (OrderNum,OrderNum)
DATA-RELATION LineItem FOR eOrderLine,eItem
RELATION-FIELDS (ItemNum,ItemNum) REPOSITION.
27
© 2005 Progress Software Corporation
Implementing the OERA
Constructing the objects –
Data Access Object

Build Data Access Object for the DataSet
– Manages all the Data-Source objects
daOrder.p
sceOrder.p
dsOrder.i
Simplify your business
sceOrderLine.p
28
© 2005 Progress Software Corporation
Implementing the OERA
Building the Data Access Object



Simplify your business

Built from the template daEntity.p
Naming convention of da + entity-name
Includes the ProDataSet definition file
Can also include FILL logic that is beyond
a single temp-table
29
© 2005 Progress Software Corporation
Implementing the OERA
All the Data Access components
together
daOrder.p
{dsOrder.i}
{daEntity.i}
SUPER
daSupport.p
initDataSources:
sceOrder.p
DEF DATA-SOURCE
ATTACH-DATA-SOURCE
RowFill handler
sceOrderLine.p
DEF DATA-SOURCE
ATTACH-DATA-SOURCE
SUPER
Simplify your business
sceItem.p
DEF DATA-SOURCE
ATTACH-DATA-SOURCE
SUPER
30
Application
Database
daOrderValidate.p
(optional)
eOrderLineModifyBeginTrans:
© 2005 Progress Software Corporation
Implementing the OERA
The Data Access Object
as a compound object



Simplify your business


31
Everything is a super procedure of the DAO
The related procedures are started according
to naming conventions
Can be run just once in a session and left
running
Its parts can be reassembled in different
ways
Validation logic can be in the DAO or
delegated to a separate procedure
© 2005 Progress Software Corporation
Implementing the OERA
Constructing the objects –
Business Entities

Build a Business Entity for each ProDataSet
– Manages business logic on the logical data
– Defines the API for access from other objects
dsOrder.i
DEFINE DATASET dsOrder
FOR eOrder, eOrderline…
etOrder.i
Simplify your business
etOrderLine.i
BusinessLogic:
END PROCEDURE.
32
© 2005 Progress Software Corporation
Implementing the OERA
Building the Business Entity




Simplify your business

Based on a template: beEntity.p
Naming convention: be + entity name
Standard behavior starts the DAO
Supporting super procedure
Optional separate validation procedure
33
© 2005 Progress Software Corporation
Implementing the OERA
Business Entity components together
dsOrder.i
beOrder.p
{etOrder.i}
{etOrderLine.i}
{etItem.i}
{dsOrder.i}
{beEntity.i}
beEntity.i
beSupport.p
fetchCustom
saveChanges
DEFINE DATASET…
RUN daOrder.p
Simplify your business
SUPER
SUPER
beOrderValidate.p
(optional)
eOrderLineModifyPreTrans:
Data
Access
Object
34
© 2005 Progress Software Corporation
Implementing the OERA
Agenda






Simplify your business

35
Introducing the OERA Implementation
Business Entities and Data Access Objects
Business Logic Issues
Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Conclusions
© 2005 Progress Software Corporation
Implementing the OERA
Example of “magic” behavior:
Callbacks set by daSupport.p
Code – support\daSupport.p
PROCEDURE initDataSources :
/* …code snippet that shows dataset check there is also code to generically check all buffers
for callbacks - Look for DataSet-level events first. */
Simplify your business
IF LOOKUP(phDataSet:NAME + "BeforeFill", cEntries) NE 0 THEN
phDataSet:SET-CALLBACK-PROCEDURE
("BEFORE-FILL", phDataSet:NAME + "BeforeFill",
TARGET-PROCEDURE).
IF LOOKUP(phDataSet:NAME + "AfterFill", cEntries) NE 0 THEN
phDataSet:SET-CALLBACK-PROCEDURE
("AFTER-FILL", phDataSet:NAME + "AfterFill",
TARGET-PROCEDURE).
/* …*/
36
© 2005 Progress Software Corporation
Implementing the OERA
Data Access Object logic Issues

Leave out logic that doesn’t need access to
the physical data
– That belongs in the Business Entity

Decide where the logic should go
–
–
–
–
Simplify your business
Single-table logic in its Data-Source proc
Logic with a larger scope in the DAO
Static versus dynamic table references
Access to other DAOs through their APIs for
complex requests
– Interaction with database trigger procs
37
© 2005 Progress Software Corporation
Implementing the OERA
Data Access Object FILL logic

Example of logic that references more than one
table in the ProDataSet
– This should go into the Data Access Object itself
PROCEDURE eOrderLineAfterFill:
DEFINE INPUT PARAMETER DATASET FOR dsOrder.
DEFINE VARIABLE dTotal AS DECIMAL NO-UNDO.
Simplify your business
FOR EACH OrderLine WHERE
OrderLine.OrderNum = eOrder.OrderNum:
dTotal = dTotal + OrderLine.ExtendedPrice.
END.
eOrder.OrderTotal = dTotal.
END PROCEDURE.
38
© 2005 Progress Software Corporation
Implementing the OERA
Data-Source Object FILL logic

Example of dynamic table reference:
– Dynamic reference allows reuse
PROCEDURE eItemAfterRowFill:
DEFINE INPUT PARAMETER DATASET-HANDLE phDataSet.
….
hItemName =
phDataSet:GET-BUFFER-HANDLE("eItem"):BUFFER-FIELD("ItemName").
Simplify your business
DO iType = 1 TO NUM-ENTRIES(cItemTypes):
cType = ENTRY(iType, cItemTypes).
IF INDEX(hItemName:STRING-VALUE, cType) NE 0 THEN
hItemName:BUFFER-VALUE =
REPLACE(hItemName:BUFFER-VALUE, cType, cType).
END.
END PROCEDURE.
39
© 2005 Progress Software Corporation
Implementing the OERA
Business Entity logic



Simplify your business

40
Validation and other business logic
Logic references the internal logical view
of the data
References to other entities through their
published APIs
Logic requiring knowledge of the physical
schema is deferred to DAOs
© 2005 Progress Software Corporation
Implementing the OERA
Business Entity logic issues

How strictly do I adhere to logic separation?
– Do I use an API call just for a CAN-FIND?
– Do I defer that to a database trigger?

Simplify your business

How do I adjust BE logic to allow for re-use
of tables in other ProDataSets?
When do I use static versus dynamic table
and ProDataSet references?
41
© 2005 Progress Software Corporation
Implementing the OERA
Business Entity update semantics
in the sample implementation




Generic saveChanges for one or multiple
rows in any number of related tables
Callouts to validation hooks based on
procedure names
Database transaction per row
Can be modified to provide:
Simplify your business
– Custom control logic for the whole update
– Saving all changes as a single transaction
– Extensions to error handling logic
42
© 2005 Progress Software Corporation
Implementing the OERA
Agenda






Simplify your business

43
Introducing the OERA Implementation
Business Entities and Data Access Objects
Business Logic Issues
Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Conclusions
© 2005 Progress Software Corporation
Implementing the OERA
SOA – Service Interaction Model
Broker/
Director
y
Service
Find /
Details
Service
Requestor
Publish
Bind
Invoke
Service
Provide
r
Enterprise
Services
Simplify your business
Bus Task
Bus Task
Bus Task
44
© 2005 Progress Software Corporation
Implementing the OERA
Application Domain Services
Presentation Container
Domain
Fn()
Service Proxy
Service Container
Simplify your business
Service Interface
Order
Mgmt
45
© 2005 Progress Software Corporation
Financials
Other
Services
Implementing the OERA
Container Managed – Support Services
Presentation Container
Client
Side
Service Proxy
Simplify your business
Service Interface
Auditing
Security
Service Container
Order
Mgmt
Server
Side
46
© 2005 Progress Software Corporation
Session/Context Management
Fn()
…
Implementing the OERA
The Service Interface Layer
in the OERA
Enterprise
Services
Users
Presentation Layer
Service
Interface
Integration Layer
Business Servicing Layer
Simplify your business
Data Access Layer
Managed
Data Stores
47
© 2005 Progress Software Corporation
Unmanaged
Data Stores
Implementing the OERA
Role of the sample
Service Interface Layer

Manages server-side entities
– Keeps an in-memory catalog of running
instances

Simplify your business

Provides standard one-call access to
server-side procedures
Provides a single simplified API from
client to server
48
© 2005 Progress Software Corporation
Implementing the OERA
The Service Interface Layer
Client
Server
UI Procedure
Business Entity
Data-Access Object
DATASET dsOrder
DATASET dsOrder
RUN fetchOrder
RUN FetchWhere
fetchWhere:
IN hEntity
FILL
(. . .,
ATTACH
(. . . ,
OUTPUT
DATASET
dsOrder
Simplify your business
BY-REFERENCE)
49
Client Proxy Procedure
IN hdsOrder
© 2005 Progress Software Corporation
Server Gateway Procedure
DATASET dsOrder
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
Implementing the OERA
Client-side SI proxy
User interface
Client proxy
procedure
procedure
dsOrderWinAdv.w
Simplify your business
{dsOrder.i}
{proSIproxyStart.i}
…
RUN fetchWhere IN
ghProxySIproc
(INPUT “Order”,
INPUT ttContextDSOrder,
OUTPUT DataSet dsOrder).
proSIproxy.p
PROC fetchWhere:
RUN proSIgateway.p ON
hAppServer
(INPUT “Order”,
INPUT “fetchWhere”…)
PROC saveChanges:
…
(call to server-side
gateway)
50
© 2005 Progress Software Corporation
Implementing the OERA
Server-side SI procedures
Server service
(call from client
session)
Server gateway
procedure
proSIgateway.p
hEntity = getEntityHandle
in hSI.
RUN fetchWhere in hEntity
procedure
proSIserver.p
DEFINE T-T ttEntity…
FN startEntity:
FN getEntityHandle:
FN getDAOHandle:
Simplify your business
…
(call to Business
Entity API)
51
© 2005 Progress Software Corporation
Implementing the OERA
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
– OUTPUT status for exception handling
Useful default for many operations
Simplify your business

52
© 2005 Progress Software Corporation
Implementing the OERA
Agenda






Simplify your business

53
Introducing the OERA Implementation
Business Entities and Data Access Objects
Business Logic Issues
Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Conclusions
© 2005 Progress Software Corporation
Implementing the OERA
Management of ProDataSet
instances


Simplify your business

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
54
© 2005 Progress Software Corporation
Implementing the OERA
ProDataSet instances on
OUTPUT
Client
Server
UI Procedure
Business Entity
Data-Access Object
DATASETDATASET dsOrder
BY-REF
HANDLE
HANDLE
(. . . ,
OUTPUT
DATASET
dsOrder
Simplify your business
BY-REFERENCE)
55
Client Proxy Procedure
IN hdsOrder
© 2005 Progress Software Corporation
Server Gateway Procedure
RUN fetchOrder
DATASET dsOrder
BY-REF
DATASET dsOrder
RUN FetchWhere
fetchWhere:
IN hEntity
FILL
(. . .,
ATTACH
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
Implementing the OERA
ProDataSet instance on
INPUT-OUTPUT
Client
Server
UI Procedure
DATASET dsOrder
Business Entity
DATASETHANDLE
HANDLE
BY-REF
(. . . ,
OUTPUT
DATASET
dsOrder
Simplify your business
BY-REFERENCE)
56
Client Proxy Procedure
IN hdsOrder
© 2005 Progress Software Corporation
Server Gateway Procedure
RUN fetchOrder
DATASET dsOrder
Data-Access Object
BY-REF
DATASET dsOrder
RUN FetchWhere
fetchWhere:
IN hEntity
FILL
(. . .,
ATTACH
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
Implementing the OERA
Agenda






Simplify your business

57
Introducing the OERA Implementation
Business Entities and Data Access Objects
Business Logic Issues
Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Conclusions
© 2005 Progress Software Corporation
Implementing the OERA
Context Management basics


Simplify your business

Target environment is client to
stateless AppServer
Each interaction is independent
Maintain context between related
interactions
58
© 2005 Progress Software Corporation
Implementing the OERA
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
Simplify your business
– Also for context used on the client
– And for context modified on the client
59
© 2005 Progress Software Corporation
Implementing the OERA
Context between client and server
Server
Client
Business Entity
UI Procedure
DATASET dsOrder
DATASET dsOrder
(. . . ,
OUTPUT
DATASET
dsOrder
Simplify your business
BY-REFERENCE)
60
Client Proxy Procedure
IN hdsOrder
temp-table
WhereString = “…”
NextRowid = 63524
© 2005 Progress Software Corporation
RUN FetchWhere
Server Gateway Procedure
context/parameter
RUN fetchOrder
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
Implementing the OERA
Client to Server context example –
support for data batching



Simplify your business

WhereString = “OrderNum = 27”
NextRowid = 63726
Server reprepares and reopens the
database query on each call
NEXT-ROWID ProDataSet attribute tells
server where to restart retrieval
61
© 2005 Progress Software Corporation
Implementing the OERA
Context maintained on the server


Hold context in a shared server-side
data store
Useful for context not to pass back and forth
– Session context such as language,
authorization

Requires a Context ID passed from the client
Simplify your business
– GUID support in sample and in OE 10.1
62
© 2005 Progress Software Corporation
Implementing the OERA
Context stored on the server
Server
Client
Business Entity
UI Procedure
DATASET dsOrder
DATASET dsOrder
(. . . ,
OUTPUT
DATASET
dsOrder
Simplify your business
BY-REFERENCE)
Client Proxy Procedure
IN hdsOrder
temp-table
ContextID = 95847
RUN FetchWhere
Server Gateway Procedure
context/parameter
RUN fetchOrder
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
95847 English Auth …
63
© 2005 Progress Software Corporation
Implementing the OERA
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
Simplify your business
– Allows partial validation on the server
– Final update ProDataSet rebuilt from
context
64
© 2005 Progress Software Corporation
Implementing the OERA
ProDataSet / temp-table
data as context
Server
Client
Business Entity
UI Procedure
DATASET dsOrder
DATASET dsOrder
ContextID = 95847
(. . . ,
OUTPUT
DATASET
dsOrder
Simplify your business
BY-REFERENCE)
Client Proxy Procedure
IN hdsOrder
“OrderNum = 1”
95847 Order 1 Line 1
RUN FetchWhere
Server Gateway Procedure
RUN fetchOrder
IN hEntity
(. . .,
OUTPUT
DATASET
phFetchDataSet
BY-REFERENCE)
95847 Order 1 Line 1
95847 Order 1 Line 2
65
© 2005 Progress Software Corporation
Implementing the OERA
Agenda






Simplify your business

66
Introducing the OERA Implementation
Business Entities and Data Access Objects
Business Logic Issues
Introducing the Service Interface Layer
Managing ProDataSet instances
Context Management
Conclusions
© 2005 Progress Software Corporation
Implementing the OERA
Directions



Simplify your business

First set of papers & examples on PSDN
New papers coming before Exchange
Significant new language extensions
planned for 10.1 and beyond
Materials to be revised and extended to
describe 10.1 best practices
67
© 2005 Progress Software Corporation
Implementing the OERA
In Summary




Simplify your business

68
View the sample OERA materials as a
basis for discussion and learning
Use parts that are useful
Extend or replace for your own purposes
Expect it continue to grow and change
Don’t expect it to be completed or formally
supported
© 2005 Progress Software Corporation
Implementing the OERA
Simplify your business
Questions?
69
© 2005 Progress Software Corporation
Implementing the OERA
Simplify your business
Thank you for
your time!
70
© 2005 Progress Software Corporation
Implementing the OERA
Simplify your business
71
© 2005 Progress Software Corporation
Implementing the OERA