Zooming Layout Showing and Hiding Unconnected Beans

6-8 Oracle Complex Event Processing Developers Guide Figure 6–12 Configuration Badging Nodes with this badge will also have the Go To Configuration Source context menu item.

6.2.8 Link Specification Location Indicator

When working with streams, you can specify a link in the assembly file as a: ■ source element in the downstream node. ■ listener element in the upstream node A circle on the line indicates where a particular link is specified in the assembly file. Figure 6–13 shows an example in which the link is specified as a source element on the downstream node outStream so the circle is next to the outStream node. Figure 6–14 shows the corresponding assembly file. Figure 6–13 Link Source Figure 6–14 Link Source Assembly File Figure 6–15 shows an example in which the link is specified as a listener element in the upstream node algoTradingProcessor so the circle is next to the algoTradingProcessor node. Figure 6–16 shows the corresponding assembly file. Figure 6–15 Link Listener Oracle CEP IDE for Eclipse and the Event Processing Network 6-9 Figure 6–16 Link Listener Assembly File

6.2.9 Nested Stages

When you define a child node within a parent node, the child node is said to be nested. Only the parent node can specify the child node as a listener. You can drag references from a nested element, but not to them. For more information, see Section 6.4.2, Connecting Nodes . Consider the EPN that Figure 6–17 shows. Example 6–1 shows the EPN assembly source for this EPN. Note that the HelloWorldBean is nested within the helloworldOutputChannel. As a result, it appears within a box in the EPN diagram. Only the parent helloworldOutputChannel may specify the nested bean as a listener. Figure 6–17 EPN With Nested Bean Example 6–1 Assembly Source for EPN With Nested Bean wlevs:adapter id=helloworldAdapter class=com.bea.wlevs.adapter.example.helloworld.HelloWorldAdapter wlevs:instance-property name=message value=HelloWorld - the current time is: wlevs:adapter wlevs:channel id=helloworldInputChannel event-type=HelloWorldEvent wlevs:listener ref=helloworldProcessor wlevs:source ref=helloworldAdapter wlevs:channel wlevs:processor id=helloworldProcessor wlevs:channel id=helloworldOutputChannel event-type=HelloWorldEvent advertise=true wlevs:listener bean class=com.bea.wlevs.example.helloworld.HelloWorldBean wlevs:listener wlevs:source ref=helloworldProcessor wlevs:channel Alternatively, you can define this EPN so that all nodes are nested as Figure 6–18 shows. Example 6–2 shows the EPN assembly source for this EPN. Note that all the nodes are nested and as a result, all nodes appear within a box in the EPN diagram. The helloworldAdapter is the outermost parent node and does not appear within a box in the EPN diagram.