The WorkflowManager
The class org.imixs.workflow.WorkflowManager is the central interface for each implementation of an Imixs-Workflow Engine. This interface provides the general functionality to create, process and search Workitems.
The WorkflowManager instantiates the WorkflowKernel to process a WorkItem and provides the implementation of a Model. The WorkflowManager can be used by an application to process and search Workitems and provide the environment for the business logic implemented by the plugins.
| Method | Return Type |
|---|---|
| processWorkItem(ItemCollection workitem) | Processes and persists a workItem. The WorkItem must provide at least the mandatory items $modelVersion, $taskID, and $EventID to identify the current state in a BPMN model. |
| getWorkItem(String id) | Returns a workItem by its uniqueID ($uniqueID) from the persistence layer |
| removeWorkItem(String id) | The method throws an AccessDeniedException if the work item cannot be removed due to its state or user permissions. |
The WorkflowManager Service implements the WorkflowManager based on the JEE architecture.
The Plugin-API
The general workflow functions and also application specific business logic is provided by Plugin API. The WorkflowManager can register a specific set of plugins to be called by the WorkflowKernel when processing a Workitem. A typical code example is structured as follows:
....
// init WorkflowKernel
WorkflowKernel workflowKernel =new org.imixs.workflow.WorkflowKernel(workflowContext);
// register plugins.....
workflowKernel.registerPlugin("org.imixs.workflow.plugins.AccessPlugin");
workflowKernel.registerPlugin("org.imixs.workflow.plugins.HistoryPlugin");
// processing workitem...
myWorkitem=workflowKernel.process(myWorkitem) ;
....
Processing a Workitem
The method ‘processWorkItem()’ is used to create or update a Workitem. The WorkflowManager implementation is responsible to load the Model, call the WorkflowKernel and persist the Workitem so it can be retrieved later by the application.
public void processWorkItem(ItemCollection aWorkItem)throws Exception {
// ...instantiate workflowKernel...
// ...register plugins to workflowKernel...
aWorkItem=workflowKernel.process(itemCol);
// ...save the workitem...
....
}
The WorkflowKernel can throw a ProcessingErrorException if the Workitem did not match the model status. Therefore the WorkflowManager implementation have to verify if the Workitem provides valid values for the properties ‘$taskID’ and ‘$eventID’.
Find Workitems
The property “$uniqueid” identifies the workitem controlled by the workflowManager. This ID can be used to load a workitem from the WorkflowManager:
workitem=wfm.getWorkItem(uniqueid);
It is also possible to receive a list of workitems for the current user by calling the method getWorkList().
List<ItemCollection> worklist=wfm.getWorkList();
The method returns a list of all workItems assigned to the current user. A workitem is typically managed by a WorkflowManger for the complete life cycle. To remove a workitem from the WorkflowManager underlying database you can call the removeWorkitem method:
wfm.removeWorkItem(workitem);
The Imixs WorkflowService
The Imixs-Workflow engine provides the WorkflowService component which implements the WorkflowManager on the JEE component stack. Find more information about the Imixs-WorkflowService in the section WorkflowService.
