Data sent between agents in workflows is either represented as UDRs (Usage Detail Records) or as raw data. Raw data is sent as bytearrays, while UDRs are to be treated as individual records.

Due to the various formats of incoming data, the system does not provide any hardcoded formatting rules. Instead, it provides the Ultra subsystem where nearly any format may be defined and handled using the Ultra Format Definition Language (UFDL). Such definitions will automatically compile into classes, implementing the DRUDR interface. In addition, the DTK provides the possibility of coding such classes directly in Java.

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DRUDR

UDR related classes are located in the package com.digitalroute.devkit.drudr.

DRUDR

UDRs developed using the DTK must extend the DRAbstractUDR class, which uses Java reflection to implement all DRUDR methods, except for the actual field data manipulation. A DRUDR class is intended to be a data carrier, and thus it will require methods for setting and retrieving user defined values, as it walks its way through a workflow. Such values are referred to as fields.

By implementing method names prefixed with the get_ and/or set_ keywords, the UDR subsystem uses Java reflection mechanisms to obtain information about available fields, such as their access type and data type. DRUDRs contain a list of possible error codes that may be useful if UDRs are routed to ECS. Error codes may be added using addErrorCode, examined via getErrorCodes and removed by clearErrors. Finally, a description of the UDR Type and its fields may be obtained using getDRUDRDesc.

public class MyUDR extends DRAbstractUDR {

              private String _name;

                private int _age;
   public void set_name(String newName) {
      _name = newName;
   } 
   public String get_name() { 
      return _name; 
   } 
   public void set_age(int newAge) { 
   _age = newAge; 
   } 
   public int get_age() { 
      return _age; 
   } 
   public boolean get_isChild() { // Read only field 
      return _age < 18; 
   } 
   // writeTo and readFrom methods are omitted 
}

MyUDR udr = new MyUDR(); 
udr.setValue("name", "Karen"); 
udr.setValue("age", 10); 
udr.setValue("isChild", true); // Will cause exception 
System.out.println( 
  "Name: " + udr.getValue("name") + 
  "Age: " + udr.getValue("age") +
  "Child: " + udr.getValue("isChild"));

MyUDR udr = udrCreate(MyUDR); 
udr.name = "Karen"; 
udr.age = 10; 
udr.isChild = true; // Will cause APL compilation error 
debug( 
  "Name: " + udr.name + 
  "Age: " + udr.age + 
  "Child: " + udr.isChild);

The Ultra format system allows the definition of nested UDRs. That is, for instance, a UDR within another UDR. Addressing fields in such UDRs is done by so called qualified names where a dot (".") separates each level.

For a DRUDR plugin example, see:

com.digitalroute.devkit.examples.udr.*

DRUDRDesc

The DRUDRDesc class contains information about a specific UDR Type. An instance of this class may be obtained from a DRUDR and a list of all available UDR Types in the system from the DREnvironment. The class offers methods such as getFields, which returns a list of DRUDRField instances that describe each field.

DRUDRDesc extends the DRUDRType class, where each returned field's type may be examined. A returned field could be a primitive field but also a nested UDR (DRUDRDesc), a list (DRUDRListDesc), a map (DRUDRMapDesc), a table (DRUDRTableType) or a byte array (DRUDRRawDataDesc).

The system automatically creates DRUDRDesc instances for all UDRs defined in the system.

DRUDRField

A DRUDRField represents an element within a UDR. The getFieldName method returns the element name and getType returns the type of the element. The returned type could be a primitive field, such as a string or integer, but also a composite type, such as another DRUDRDesc or any other DTUDRType subtype.

If traversing a nested DRUDRDesc, the returned field's type has to be examined and if it is of type DRUDRDesc the a further examination needs to be performed.

DRUDRType

To be able to support type validation and automatic code generation, Image Added implements a type description system that is separate from standard Java class handling. The base class for all type descriptions is DRUDRType, and various UDR types are described by subclasses of DRUDRDesc.

The following table lists the available types, their type descriptions and the runtime implementation classes.