How to Manage Business Data

In a business application information need to be managed and distributed in a predefined way. Users edit data, which need to be made available for various actors. Back-end applications need the data to track the status or trigger different events. The data which is processed by a workflow management system is stored into a database and synchronized with a business process. This data is called the ‘workitem’.

The data, which is usually edited by a user or controlled by an application is called the ‘business data’. The Data which is managed by the workflow system is called the ‘workflow data’. The workflow data contains all information about the current state of a ‘process instance’. So a workitem holds business data, entered by a user or controlled by an application, and also processing information controlled by the workflow system.

Business data

To manage the data of a workitem, the Imixs Workflow project provides the simple data object - called ItemCollection. A ItemCollection holds a list of Items that can store any type of data. There are no restrictions in the amount or size of the data stored into an ItemCollection. See the following example:

import org.imixs.workflow.ItemCollection;
.....
ItemCollection workitem=new ItemCollection();
workitem.setItemValue("name","Anna");
workitem.setItemValue("age",new Integer(32));

Each item stored into a ItemCollection has a item-name and a item-value. The item-name identifies a specific part of data contained in a ItemCollection. You can access a item-value by its name:

....
String name=workitem.getItemValueString("name");
int age=workitem.getItemValueInteger("age");
....

You will find more information in the section ItemCollection.

Workflow data

As explained before, a workitem can not only contain business data, but also information about the process instance which is controlled by the workflow engine. This workflow data of a process instance contains for example the creation date or the processing status. This is an example how to access this kind of data:

String uniqueID=workitem.getUnqiueID();
int taskID=workitem.getTask();
String status=workitem.getItemValueString(WorkflowKernle.WORKFLOWSTATUS);
Date created=workitem.getItemValueDate("$created");
Date modified=workitem.getItemValueDate("$modified");

The following table provides an overview about all data items managed by the Imixs-Workflow Engine. The column ‘read/write’ indicates if the item can be controlled by an application. The column ‘indexed’ indicates if the item can be searched by the search index:

Property Type read/write indexed Description
$ModelVersion String yes yes The Version of the model the workitem belongs to
$TaskID Integer yes yes The current taskID of the workitem
$EventID Integer yes yes Current event processed by the Workflow Engine. Is 0 if no processing lifecycle is executed.
$workflowGroup String no yes The name of the current process group
$workflowStatus String no yes The name of the current workflow status
$Created Date no yes Date of creation
$Modified Date no yes Date of last modification
$ReadAccess List no yes String list of User/Roles with read access
$WriteAccess List no yes String list of User/Roles with write access
$uniqueId String no yes The unique ID of this workItem
$uniqueIdRef String yes yes A reference to a connected workItem (child process)
$workitemId String no yes A unique process instance id of a workitem and all its versions
$uniqueIDSource String no yes The UniqueID of the Source workitem for a version (See Workflow Kernel split-events)
$uniqueIDVersions String no yes A list of UniqueIDs to all created versions of this workitem (See Workflow Kernel split-events)
$lastTask Integer no yes The last assigned Task ID (processid)
$lastEvent Integer no yes The last processed event ID
$lastEventDate Date no yes The timestamp of the last processing action
$eventLog List no no Log of processed workflow events
$creator String no yes The user who created the workItem.
$editor String no yes The user who invoked the processWorkitem() method.
$lasteditor String no yes The last user, that invoked the process method before the $editor
$noindex Boolean yes no If set to ‘true’, the document will not be added into the index. (See DocumentService for details.)
$immutable Boolean yes no If set to ‘true’ updateing the workitem is no longer allowed. (See DocumentService for details.)
$Participants List no yes String list of Users having executed this WorkItem.
$owner List no yes String list of User/Roles, that are owners of that WorkItem.
$workflowsummary String no yes A short description of the current status
$workflowabstract String no yes A long description of the current status
$file List yes no List of FileData objects
$file.count Integer no yes Count of FileData objects
$file.filenames List yes yes List of file names
txtworkflowimageurl String no no A link to an image which displays the current status
txtworkflowresultmessage String no no The result message of last process step

Temporary Attributes

The Imixs-Workflow engine provides additional temporarily attributes. These attributes are not persisted into the database. Temporarily attributes are indicating the session state of a workitem:

Property Type Scope Description
$isAuthor Boolean read Indicates if the current user has write access. The attribute is computed when a workitem is read.
$isVersion Boolean processing Indicates if the current instance is a version to a source workitem. This attribute is computed during the processing phase.

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