Obj extensions to Java CeSdk ideas on fine-grained persistence perspectives for BIP Thierry Bravier Version 1.0 6 March 2007

obj extensions to Java CeSdk ideas on fine-grained persistence

perspectives for BIP

obj extensions to Java CeSdk ideas on fine-grained persistence

perspectives for BIP

Thierry BravierVersion 1.0

6 March 2007

Slide 2

CeSdk is very flexible and functional as it is

but requires some level of expertise to use correctly

Idea: develop a strongly typed layer over CeSdk to fully benefit from modern languages C++/Java5/.NET2&3 This presentation focuses on Java5 extensions for Java CeSdk Similar work has already been developed for C++ over wire objects

Session

Desktop plugins

Collection of info-objects

Info-object and bag

Query syntax

Copyright © 2007 Business Objects S.A. All rights reserved.

CeSdk + obj: where we are, where we could go

Slide 3

The several techniques used aim at ensuring …

Strong typing C++ templates / Java 5 generics / .NET 2+ generics Statically type everything that can be

• Typed properties that « know » their type• Typed (reified) plugins that « know » their info object type and more• Typed Query syntax API (forget about string concatenation)• Ban casts

Const correctness• By design in C++• Covariant return type in Java 5• To be explored in .NET

ie. Favor non mutable over mutable• IKSession, IKObjs, IKObj, IKProperty …• Would you want a pure consumer to unwillingly modify objects?


CeSdk + obj: techniques used (1/2)

Slide 4


Extensibility Combine predefined property types into user defined ones An IObj isAn Ibag

• So a typed property working on bags can work on objs (code re-use)



Slide 5 Copyright © 2007 Business Objects S.A. All rights reserved.

Session management can be complex To ease session life-cycle ISession is a Closeable

• close (alternatively release) must be called to release acquired resource• Currently only building session with a Logon object (session must be logged off),

but this can be generalized for tokens or serialized form

IKSession can only query const objects collections

ISession can query mutable objects collections

CeSdk + obj: ISession (1/1)

final ISession session = ISession.logon // Logon non-mutable object .userName("tbravier") // Administrator .password("sesame") // blank .authentication("secEnterprise") // secEnterprise .cmsName("tbravier-titan") // localhost .session(); // logs onsession.close();


Today, a plugin is represented by its SI_KIND string But a plugin should know its Java associated type

• A plugin can be used as a factory to extend a collection in a type-safe way• A plugin can be useful to restrict a query result set

CeSdk + obj: IObjPlugin Desktop plugins (1/2)

final IInfoObj<IFolder> folderObj = session.create(IInfoObjPlugin.FOLDER // knows about IFolder .spec(parentSid) // make sure new object has a parent .name("NewFolderName”) // optionaly specify name );

Query.select .prop(SpecialProp.STAR) .from(Ci.APPOBJECTS) .where(IInfoObjPlugin.FOLDER); // here plugin is used as a predicate


A plugin is a kind of metaclass hierarchies of plugin classes are possible A plugin can be used as a type token like Java5 classes

CeSdk + obj: IObjPlugin Desktop plugins (2/2)

// typed Java5 class literalClass<String> cls = String.class;

// typed plugin literalIObjPlugin<IPersonObj> plg = IPersonObj.plugin;

void test(String data, IPersonObj obj) { assert(data.getClass() == String.class); assert(obj.plugin() == IPersonObj.plugin);}

Slide 8


Strong typing C++ templates / Java 5 generics / .NET 2+ generics Statically type everything that can be

• Typed properties that « know » their type• Typed (reified) plugins that « know » their info object type and more• Ban casts

Const correctness ie. Favor non mutable over mutable

• IKSession, IKObjs, IKObj, IKProperty …• Would you want a pure consumer to unwillingly modify objects?

By design in C++ Covariant return type in Java 5 To be explored in .NET




CeSdk + obj: IObjs Collection (1/2)

An IObjs is iterable (type-safe) and indexed by sids

A collection of mutable objects may commit IObjs is a Flushable whose flush (alt. commit) updates CMS

An IObjs « knows » its ISession incremental loading, finding target objects of relations …

Objects are created / destroyed inside collections Simplification: ISession owns IObjs which owns each IObj

iobjs.create(IPersonObj.plugin.spec(IPersonObj.defaultFolderId));iobjs.commit();

iobjs.destroy(personObj);iobjs.commit();

final IPersonObj personObj = iobjs.create(IPersonObj.plugin .spec(IPersonObj.defaultFolderId));personObj.commit(); // shortcutpersonObj.destroy().commit(); // shortcut


An IKObjs is iterable (type-safe) and indexed by sids

An IKObjs collection only contains IKObj’s but can grow

An IKObjs « knows » its IKSession

CeSdk + obj: IObjs Collection (2/2)

for (final IUser user : ksession.objs( "select static from ci_systemobjects where si_kind = 'User'") .infos(IInfoObjPlugin.USER)) { testUser(user);}

Slide 11

How to create objects Don’t forget to set

• SI_PARENTID or SI_PARENT_CUID• SI_KIND (see slide on plugins)• SI_NAME (optionaly)

How to manage properties in a type-safe way• Property name (and associated integer value)• Type• Value• Bags

Predefined property types• boolean SiBool Boolean• int SiInt4 Integer• long SiInt8 Long• double SiFlt8 Double• String SiStrg String• Date SiTime Date


CeSdk + obj: IObj & IBag object and bag (1/4)

Slide 12

How to separate authoring & consumption when consuming missing data often means something’s wrong when authoring missing data should be inserted

How to traverse relationships relationships targets really are info objects, not sids this asks for « connected » objects that know their collection

How to access missing objects To get missing objects

• an additional query (with a merge) is needed• the session is needed

This is important for• Authoring: adding/removing objects graphs to/from edition workspace• Consumption: incremental loading depending on previous query results



Slide 13

How to simply deal with default values, null values

How to manage values properties for user-defined types Enumerated types (encoded as string, cf. SiRainbow in demo) Struct (Bag + field, cf. SiAnimal in demo) Encoding (cf. Locale …)

How to manage relations properties encoding as bags 3 kinds of relations

• Single SiSRel Integer• Unordered SiURel Set<Integer>• Ordered SiORel List<Integer>




Using predefined value and relation properties


final SiSub SI_BAG = SiSub.make("SI_BAG");final SiBool SI_BOOL = SiBool.make("SI_BOOL");final SiInt4 SI_INT4 = SiInt4.make("SI_INT4");final SiInt8 SI_INT8 = SiInt8.make("SI_INT8");final SiFlt8 SI_FLT8 = SiFlt8.make("SI_FLT8");final SiTime SI_TIME = SiTime.make("SI_TIME");final SiStrg SI_STRG = SiStrg.make("SI_STRG");

final SiSrel SI_SREL = SiSrel.make("SI_SREL");final SiUrel SI_UREL = SiUrel.make("SI_UREL");final SiOrel SI_OREL = SiOrel.make("SI_OREL");

final double flt8 = obj.set(SI_BAG).set(SI_BAG).set(SI_FLT8);final String strg = obj.set(SI_BAG).set(SI_BAG).set(SI_STRG);final Date time = obj.set(SI_BAG).set(SI_BAG).set(SI_TIME);

final int int4 = obj.get(SI_BAG).get(SI_BAG).get(SI_INT4);obj.set(SI_BAG).set(SI_BAG).set(SI_INT4, int4 + 1);

final Integer si_srel = obj.get(SI_SREL);


let’s take a look !


CeSdk + obj: typed properties (1/2)

values


CeSdk + obj: typed properties (2/2)

relations


Queries are immutable Libraries of useful query contants can be written

Forget about escaping, precedences and string concat

Value properties become predicates

Relation constants (not detailed) become predicates

Plugins become predicates

CeSdk + obj: Query syntax (1/2)

Query.select .top(5) .prop(SI_NAME, SI_DESCRIPTION, SI_FULLNAME) .from(Query.Ci.SYSTEMOBJECTS) .where(IInfoObjPlugin.USER .or(SI_ID.eq(95))) ;


Using relation traversal predicates (descendents …)

CeSdk + obj: Query syntax (2/2)

Query.select .top(5) .prop(SI_NAME, SI_DESCRIPTION, SI_CUID, SI_UPDATE_TS, SI_KIND) .from(Query.Ci.APPOBJECTS) .where(IPersonObj.plugin // ie. SI_KIND.eq("TB_Person") .and(FOLDER_HIERARCHY.descendents(SI_ID.eq(95))) .and(SI_NAME.in("John", "O'Brien"))) ;

Slide 20

obj and mes code dependency graph


obj package extends CeSdk• Strongly typed• Generics

persistence exposes• Metadata (cf. xsd+) in plugins objects• Inversion of control (ioc)

• Plugins register into the application• Application loads plugins

meta = persistence + obj• Fine-grained authoring &

consumption algorithms


obj and mes code metrics

MES packages in lines of code (loc)

Total size of code = 22 kloc

mes3852% persistence

455523%

plugin7384%

meta732637%

obj669434%

mes

persistence

plugin

meta

obj

Slide 22

obj + persistence = meta UML design


service

service

«interface»IEditionContext

«interface»IRetrievalContext

«interface»plugin::IServiceContext

«interface»IElem

+persistentId() : string

«interface»IIdElem

+folderId() : string

«interface»ITopElem

+editor()+retriever()

«interface»IElemPlugin

«interface»IIdElemPlugin

«interface»ITopElemPlugin

«metaclass»plugin

«metaclass»plugin

«metaclass»plugin

+commit()

«interface»IEditionManager

+retrieve(in cuid : string)

«interface»IRetrievalManager

«interface»IDeployableManager

+create()+setElemField()+destroy()

«interface»IEditor

+getElemField()

«interface»IRetriever

«interface»plugin::IService

service

+deploy(in topModelPlugin : ITopElemPlugin)+deploy(in topModelClass)

«interface»plugin::IDeployable

+service(in modelClass)

«interface»plugin::IManager

context

context

context

kelems

«interface»IElems

«interface»IKElems

elems

«interface»meta::IMetaObj

«interface»meta::IIdMetaObj

«interface»meta::ITopMetaObj

«interface»meta::IMetaObjPlugin

«interface»meta::IIdMetaObjPlugin

«interface»meta::ITopMetaObjPlugin

«metaclass»plugin

«metaclass»plugin

«metaclass»plugin

«interface»obj::IBag

«interface»obj::IObj

«interface»obj::IObjPlugin

«metaclass»plugin

«interface»obj::IObjs

«interface»obj::ISession

«interface»meta::IMetaObjs

Documents

Obj extensions to Java CeSdk ideas on fine-grained persistence perspectives for BIP Thierry Bravier Version 1.0 6 March 2007