Workflow Development Summary

workflow development has been around for a while. Here, I will summarize some of my ideas. The workflow engine does not include peripheral implementations, such as the process definer, management control, and work item list.
the workflow engine is actually a state machine, but other work is added to the state change process. I understand the responsibilities of the workflow engine as follows:
1. Support for workflow mode.
This is undoubtedly the most important part. The change of State usually depends on the choice of different modes. The more supported modes, the less your development code will be. The technical level of a workflow engine depends largely on the number of engine support modes.
2. transfer and conversion of workflow variables.
the workflow engine interacts with external applications through workflow variables. workflow variables are transmitted between each activity node, parent process, and child process. In addition to basic types (such as string and INT), variables also need to support some complex data types (such as objects, in a way of configuring ing ). This also involves a context issue.
3. task item allocation.
the assignment of task items is often associated with the Workflow Organization permissions. In fact, the purpose of the Workflow Organization permissions is to determine the task item allocation and who will complete the task. Work items also involve a lot of content, such as work item rollback and recall.
4. Call an external application.
simple form push is no longer applicable. The activity Node itself needs to support many business operations. These operations are irrelevant to the engine itself and related to external applications, therefore, the engine must provide a mechanism to call external applications. External applications can be in the form of JavaBean, WebService, and RCP.
In addition to the above four aspects, there are still some peripheral work, such as time service and node event mechanism.
for customers, they only need two interfaces: task item management interfaces (such as submitting task items and delegating task items) and Process status management interfaces (such as starting a new process instance and promoting process flow ). Ideally, it is also a good way to provide users with a fully encapsulated commit page and parent action.