CLASS

 

Ø  Class:

à Class is a blueprint (of types Abstract & Concrete) whereas Object (Instance) is an instance of it (i.e. Concrete class)

à Used to organize & re-use the code (rules) in it

à Pega Class represents the applicability (or scope) of the rule & used to organize & reuse the rules and is also a rule of type Rule-Obj-class

F Applicability (Apply to field on ‘Class Create form’) = how reusability is defined

Ø  Inheritance types: Reusing the rules from parent classes

Inheritance is the process of reusing the code (rules) from Parent to child but not vice-versa

It has 2 types:

1)      Directed (mandatory):

Regardless of the names relationships, the inheritance is known as directed Inheritance

Represented by SOLID line

2)      Pattern (Optional):

Relation between the classes in which the prefix of child class must match with Parent class

Note: If any class has both the inheritances (parents), the relation is called Dual inheritance

Represented by DOTTED line

Ø  Class Types:

1.      Abstract Class: (only definition)

à It is a generalized class which can't be instantiated (only definition)

à Only definition (of code), no implementation, so no table is mapped to it

2.      Concrete Class: (Both definition & Implementation)

à It is a specialized class which can be instantiated

à Both definition (of code) & implementation, so table must be mapped to it

à Concrete Class types:

1)      is a class group class is an instance of Data-Admin-DB-Class Group, used to store its related work objects into a single table & is identified by pyID

ð Work pool is a collection of work types, which grants access to users to create work objects that are part of that application

2)      belongs to a class group class (Work class or Work type or Case type) is a concrete class derived from work- base class & it must have Class Group as pattern parent and it defines the type of work being performed (through Starter Flow rule)

3)      does not belong to a class group class is a concrete class derived from the class other than work- class(mostly from Data- layer) and it should not have Class Group as pattern parent and even not work- as directed parent and it has mostly data objects to define reference data (application data)

Ø  Implementation class (Implementation layer): Is a class that belongs to your Application Rule Sets

Ø  Framework class (re-used FW layer): Is a class that belongs to a RuleSet that is not one of your Application Rule Sets

Ø  Internal Class: Is a Class that corresponding to instances saved in the PegaRULES database

Ø  External Class: Is a Class that corresponding to instances saved in the database other than PegaRULES

Ø  To reuse FW functionality into Implementation layer:

a)      Provide FW as built on Application

b)      Class compatibility (Work Class > FW Class as Directed parent)

Ø  PRPC standard (OOTB – Predefined) Class hierarchy:

@baseclass Work-   Data-   Assign-   History-    Index-   Code-    Embed-   Rule- ... 25+ base classes

·         @baseclass is the ultimate base (top-level abstract) class in Pega whereas OBJECT is in JAVA

à We need to create our top-level abstract class on our Organization name, say IBM-called Enterprise level class (ECS–Organizational layer) which is usually derived from Work-Cover-

à @baseclass again contains 22+ base classes as its immediate layer

·         Work– :  Regularly used for transactions (Work objects are derived from it)

à Work- base class is the immediate abstract class to @baseclass.

à This Work layer is used to define Work (transactional) data

à Our Implementation & Framework layers must be indirectly inherited from this Work-

à Work-Cover-: Cases (Cover objects) are generated from it (Case Management)

à Work-Folder-: Folder objects are generated from it

à Work-Object-: Normal Work objects are generated from it

·         Data– :  Regularly used for multi-purpose (Data objects are derived from it)

à Data- base class is the immediate abstract class to @baseclass

à This Data layer is used to define Reference data i.e. application data (stored in Data Table); Repeating data i.e. embedded data(stored in Index Table); Maintenance data (like Data- instances as OperatorID...); global level Common info (like Section created here with Properties)

F Global level Common info: Moreover, the functionality (rules) defined here can be re-used globally across applications by accessing through different page references, without creating the same rules repeatedly

à The rules created in (applied to) this Data layer can be accessed into other classes like Work layer by using pages

·         Assign–: Regularly used, but very important (Assignment objects are derived from it)

à Assign- base class is the immediate abstract class to @baseclass

à This Assign layer is used to define assignments (pending cases) routed to assignees

à Assign-Worklist concrete class: Worklist assignments are stored in pc_assign_worklist

à Assign-Workbasket concrete class: Workbasket assignments are stored in pc_assign_workbasket

à Its Foreign key is: pxRefObjectKey

·         Index–:  Rarely used, used for indexing of embedded data

à Index- base class is the immediate abstract class to @baseclass

à Indexing supports easy reporting & rapid data access, so this Index layer is used to define indexing between Work & Index tables using KCP in the order i.e. pxInsIndexedKey (pk), pxIndexCount (row number) & pxIndexPurpose (Declare Index name)

·         History–: Not regularly used (Automatic process for Work, Rule and  most Data objects)

à History - base class is the immediate abstract class to @baseclass

à This History layer is used to define history objects for Work, Data, Rule to its respective history tables i.e. pc_history_work, pr_data, pr4_history_rule

à These instances are automatically created for each Work, Data, Rule instances. We also can create audit trail as needed using Add History activity, History-Add method

à You also can control Work history records not to write into its History table using both the System Settings rule Pega-ProCom.FilterHistory (set 2 = WRITE_NONE according to your production level) and run the Activity resetFilterHistory (History-Work-) or restart the server respectively. So that you can improve system performance by reducing the number of unnecessary history writes to the pc_history_work table.

F Use Decision Tree rule FilterHistory (Work-) to restrict the history records to be written

·         Code- : Mostly used in embedded data context, but reserved (Read-only records)

à Code- base class is the immediate abstract class to @baseclass & Reserved for Pega 7 Platform's own implementation

à Code- classes directly reference server program code.

à You cannot define classes that are derived from Code- classes

à Pages of Code- classes exist only on the clipboard, so we can work these Properties & Pages; these pages can’t be saved to PegaRULES  db because these exist only temporarily in memory

à Log-in screen is loaded by Code-.Web-Start activity

à Code-Pega-List is similar to Result set in JAVA

·         Embed-:  Not used (used to hold embedded data, but Data layer is used as an alternate to it regularly)

à These are never to be used as top-level structures. No saved instances of concrete Embed- classes ever exist and used only for embedded pages

·         Rule-:  Regularly used by Developers (coding part)

à Rule- base class is the immediate abstract class to @baseclass

à This Rule layer is used to define Rule instances to build the project by developers

à Rule Resolution is applied only on these Rule- instances