Web diagram connections

A connection can represent either a logic flow or a data flow. Several specific types of connections are possible for Web applications that are based on Faces or Struts.

Logic flow

A logic flow connection in a Web diagram represents how a page or an action can execute to the next page or action. For example, a link from a Web page to another page represents how the first page can go to or "flow" to the next page. Similarly, an action mapping's forward represents the possibility that this action can go to its next destination (through a forward).

A line drawn from a Web page to a Web page, action mapping, or Web application node is a logic flow connection. A line drawn from an action mapping to an action mapping or Web page is also a logic flow connection.

Data flow

A data flow connection is a line that represents a possible flow of data through beans from a Web page or an action mapping. Two types of data flow connections exist: a declared data reference and a procedural data reference.

Declared data reference

This connection type is shown, by default, as a blue line. (You can change the default color by setting a Web diagram preference.)

A line drawn from an action mapping to a form bean, that is specified in the Struts configuration file's action mapping declaration represents a declared data reference. The first connection made from an action mapping to a form bean is assumed to be a declared data reference. By contrast, any subsequent connections from that action mapping to other form beans are assumed to represent bean references from within the action mapping's action class and are shown as procedural data references.

A line drawn from a Web page to a Java bean or form bean, where the bean is referenced in the Web page by a useBean tag, is also a declared data reference.

Procedural data reference

This connection type is shown, by default, as a green line. (You can change the default color by setting a Web diagram preference.)

A line drawn from an action mapping to a Java bean is a procedural data reference. Any connection from an action mapping to a form bean, apart from the first one that you create for that action mapping, is a procedural data reference.

Types of connections

Table 1 shows the various types connections possible between Faces or Struts nodes.

Table 1. Types of connections for Faces and Struts
Connection category	Connection type
Faces	Faces outcome
Faces	Faces action ref
Java	Java bean
Struts	Action-mapping input
	Action-mapping local forward
	Action-mapping global forward
	Action-mapping local exception
	Action-mapping global exception
	Form bean
	Action mapping configured as a forward
	Action mapping configured as an include
	Struts module exit
Web	Web-page link

Related concepts

Web diagrams and the Web diagram editor