SAP Inside Track Frankfurt 2016 Best Practices Building OData Services

1. – SAP Gateway Builder –
Building OData Services
Best Practices
Daniel Ridder (V2016-03-09)

2. Topics
• Modeling and Creating Entities
– Basics
– Namespaces
– Search-Helps
– Re-Use OData Services
• Service Implementation
– Mapping
– Extend/Overwrite Mappings
– OData is type based
– SAP Annotations
Hints&Hacks using SAP NetWeaver
Gateway Builder for creating „good“
OData-Services
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3. MODELING AND CREATING ENTITIES
Best Practices
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4. Modeling und Creating Entities
• Create an entity via importing a
DDIC-Structure
• Do not address the underlying BO
directly for model import
 Transp. Table
 DDIC View
 CDS View
 BOPF
• Create a DDIC structure instead
 This structure may look like the
underlying CDS View for instance
 You are able to append additional
specific runtime fields later
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5. Mapping ABAP data types to OData
ABAP
• GUID (RAW16)
OData
• Set manually from Edm.Binary
(max. 16) to Edm.Guid
(without additional definition)
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http://help.sap.com/saphelp_nw74/helpdata/en/54/a326519eff236ee10000000a445394/content.htm
• Use Timestamps as Date
information (i.e. last change)
with DDIC domains
– TZNTSTMPS
– TZNTSTMPL
• Edm.DateTime
Common questions:

6. • The namespace of your service equals to the
technical service name by default
– It is influenced by your ABAP DEVC linked with
the TMS
 If you have a reserved namespace (i.e.
/acme/) remove all slashes (they are not
allowed in the XML schema and SAPUI5 will
face problems while addressing search helps)
 Use something like a common internet
address notation FQDN (i.e.
„your.company.project“).
 To impress the relation between your service
and your Fiori-Application use the same
namespace as defined in the WebIDE
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Namespaces

7. • Let the Gateway
Builder create your
search helps directly
during model import
• Be sure not creating
them twice during
another model
import
Search Helps
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8. Re-Use of Search Helps
• If you have a bunch of common search helps
– Provide a dedicated project (service) for them
– Depending on the count of your search helps it
may be worth grouping them into several services
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9. • OData 2.0 does not support
cross service usage of
entities
 To access a re-use OData-
Service include the specific
service
 Do not redefine it
• Redefinition of a service
doesn't let you create own
entities
• It focuses extending and
overwriting existing services
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Re-Use OData-Services

10. SERVICE IMPLEMENTATION
Best Practices
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11. • Map your EntitySet when ever
possible
 Let the Service Adaptation Definition
Language (SADL) do the work for you
 It will generate the specific design
time artifacts (ABAP classes) for you
 You do not need to implement OData
specifics like „$top“, „$filter“ etc.
 When using BOPF your service will be
fully CRUD compliant
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Mapping during Service
Implementation

12. • Mapping can be extended / overwritten
– Jump into ABAP Workbench and open your
service implementation *DPC_EXT class
– Redefine the appropriate CRUD-Method
– Extend: Call the generated super method first
(SADL)
– Extend/Overwrite: Add your specific code
• Use it to provide your additional transient
fields (go back to slide „Modeling und
Creating Entities“)
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Extend or overwrite your Mapping
Call the super-
method to
extend your
mapping
Add your own
code for
extending/
overwriting

13.  Do not force generic
programming
– An OData service points to a
specific well formed resource
– You deal with typed data
– Implementing the CRUD interface-
methods directly will
 force you to code OData-specifics
 move the identification of types to
another place where you have to do
it on your own
 Redefine the typed CRUD-
methods of your generated *DPC
class
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OData is type based

14. • Are essential for SAPUI5
SmartControls like
SmartTable
• Needed for UI
Adaptation at Runtime
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SAP Annotations

15. Daniel Ridder @nielseabap
Thank you.
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