Reference Classes

A Reference class is a class that contains more than one property. The properties of a reference class object are accessed with the syntax Identifier.property. The variable used as the identifier of a reference class may contain some or all of the properties of the object, or may be a pointer to other data structures that contain some or all of the properties. The implementation is dependent on the class itself and the optimization logic associated with the code generator.

The following guidelines apply to reference classes:

All reference classes can be implicitly cast into their ancestor classes.
An object of a reference class can be explicitly cast to another reference class or primitive class, if a method exists to cast it.
Reference classes cannot be declared as Public scope and must be passed between procedures as parameters.
Only the = and '= operators can be used on a reference class object.
Multiple references to a reference class object refer to the same object and return a "true" value to an equality test (e.g., a=b is true if it is the same object).
The length of a reference object is subject to the implementation of the length method within that class hierarchy.
A reference class object cannot be null.

The following reference classes exist in PSL:

Class	Description
Cache	Contains methods used to retrieve Record<class> objects from within a process' local memory, calling the Db.getRecord method if a record does not exist in the cache.
Class	Provides a runtime description of the class methods and properties.
Column	Contains properties that enable programmers to reference the attributes of a table column.
Db	Contains the set of all records within the database.
DbSet	Contains the set of all records of a single table that satisfy a common condition.
Error	Contains properties and methods that enable programmers to identify and throw exceptions. The properties describe the exception and the location in the code where it occurred.
HTML	Contains methods used to create XML documents that are typically used with web access interfaces.
IO	Provides methods and properties for data input and output.
List	Contains methods used to add and locate elements in a list.
Object	The superclass of all of the classes in PSL.
Record	Defines objects based on database table definitions. This class contains all the methods used by the database tables.
RecordACN	Subset of the Record class. It is also the account superclass (ancestor) of the RecordDEP and RecordLN classes. The RecordACN class exists exclusively to provide methods and properties for the ACN table.
RecordCIF	The customer record class. The RecordCIF class exists exclusively to provide methods and properties for the CIF table.
RecordDEP	The deposit record class. It is a subset of the RecordACN class. The RecordDEP class exists exclusively to provide methods and properties for the DEP table.
RecordLN	The loan record class. It is a subset of the RecordACN class. The RecordLN class exists exclusively to provide methods and properties for the LN table.
ResultSet	Defines the set of rows and columns resulting from a database selection operation.
Row	Treats a delimited string as a row from a table, allowing reference to elements by "column name".
Runtime	Contains methods that evaluate or produce data during the execution of the code generated by PSL, or perform other “runtime” actions, such as the Transaction Processing methods. Generally the methods found in this class cannot be pre-compiled by PSL.
Schema	Deprecated. Contains properties that describe a DQ schema table.
SchemaTable	Provides a description of a DATA-QWIK table.
TranSet	Contains properties and methods associated with transaction processing.