SharePoint State Machine Workflow Solution (a): Why use a state machine

Used to be a Windows Workflow Foundation workflow platform, more familiar with WF, the development of workflow platform to meet the company's implementation of a variety of project workflow application needs.

Recently made a SharePoint document library project with an approval process that involves SharePoint workflows; I've always heard that there are no mature workflow solutions under SharePoint, but when contacted, SharePoint is a very good workflow platform Although there are still some design and technical problems to be solved in practical applications, the SharePoint workflow can meet the needs of various projects after these problems are solved.

SharePoint workflows are based on Workflow Foundation, so let's talk about WF and find the solution to the SharePoint workflow only if you have the right understanding of WF.

The 2 most notable features of Workflow Foundation

Direct Support state machine model

State machine is the theoretical basis of workflow, but there was almost no workflow products directly support the state machine, because the general workflow products have a direct commercial purpose, the goal is the application, and state machine technology is more difficult, in order to reduce the difficulty of application, the state machine will be encapsulated, So that the process can be implemented in a flowchart jump. In exchange for ease of use by sacrificing functionality.

WF's goal is a basic framework, so you can directly support the state machine model, although the development has a higher technical difficulty, but to achieve a perfect flow of circulation function. On top of WF, you can build different platforms to meet the needs of different applications.

Our workflow platform implemented hundreds of business processes, are using state machine, no one can be achieved through sequential flow, so the state machine is WF application basis, only through the state machine to achieve complex process logic. Some people get the process back by adding loops to the sequential stream, which greatly improves the complexity of the process and limits the functionality of the process.

Fine-grained activity

WF's basic component is the activity, the number of the movement is very small, the function is very fine, all the flow-related statements required in the code have almost all the corresponding activity; Through the inheritance of the existing movement, the function can be expanded conveniently; CodeActivity can facilitate the implementation of business logic.

But there are some WF and SharePoint workflow solutions that encapsulate the activity, no longer support the native activity, and may have some benefits for the development of the process, but the development of the business logic is a big hassle.

Relationship between SharePoint workflows and WF

WF is a workflow engine that implements process-driven functionality and provides a process-driven interface to the outside, which can be applied both to human-computer interaction processes and to industrial control processes. But WF technology is more difficult, the code is complex, in WF to develop a simple man-machine interaction process, but also need to understand its complex mechanism, the implementation of the process-driven interface, write a large number of code.

SharePoint is a workflow platform that is applied to the human-computer interaction process, and implements the role or person-driven functionality on the WF process-driven interface. So on SharePoint, you don't need to know the mechanism of the WF process-driven interface, and you don't need to write code to implement a simple human-computer interaction process.