Web workflow management system development 3 visualization process designer

In the workflow management system, all the activities, drivers, and flows of the engine are carried out based on the process definition. A process definition file is a prerequisite for a process to run. A process definition file is also the basis of the workflow engine design. The engine must be able to generate, interpret, and obtain information about any process definition node. Business process modeling is to describe a specific business process system with a process definition file. The visual editing tool that generates the process definition file is the process designer.

Generally, as long as you are familiar with the steps and the meaning of the nodes defined in the process, the process description file can be generated manually using a text editor. However, this is too demanding for users. A visual process definition tool is usually used.

Workflow definition tool implementation method:

Use the Java graphical interface package to implement:

To generate a Java application, JRE must be installed on the client, which is a C/S application. JRE must be installed on each client to install this visual editing tool, this method is not suitable for publishing the Web management system. Each client needs to be installed, which is not ideal;

Using Applet:

This solution solves the problems of installing each client.ProgramBut you still need to download a large number of installation packages and download JRE, which is not the ideal implementation method.

Use HTML + JS + ajax to implement:

You do not need to install the client or download JRE. It is only the first time you need to download all JS scripts. This is an ideal implementation method.

The following describes how to implement HTML + JS + Ajax:
Workflow process definition must be modeled in a graphical way to make Process Modeling simple and operable. You can drag, pull, point, or drag the workflow to build a process.
Use HTML and DHTML to display the interface.
Through JavaScript and XML, Dom analysis enables Dynamic Modification and editing of node attributes.
Use ajax to interact with the background.
Use VML to implement graphical operations, draw lines, draw boxes, and drag.

Using technologies such as JS, DHTML, XML, Dom, and VML, You can flexibly and easily edit the interface. Then, AJAX can be used to interact with the background at any time, and web pages are released at the same time, it can be integrated and released with applications, and can be opened to end users through permission control.

Generally, the process definition file can be saved as a file or saved to a database table, because it is designed to be saved in Ajax mode, both methods can be easily implemented. At the same time, it is easy to upload and download processes by saving files and databases.

The following is a simulation of the Business Process Modeling tool operation interface:

Related links:
Workflow concept in Web Workflow Management System Development
Web workflow management system development 2 workflow engine