A composition service is invoked using an <invoke> element.

Below are possible attributes and child elements for an <invoke> element, plus an example script and diagram:

Example

The following script invokes composition services using the <invoke> element with different options. The first service (VPN) will use a timeout value of 1500 ms; the second service (HomeZone) will use all the defaults; and the last service (PrePay) is so important that if it times out, the processing of the service composition will be terminated.

VIA diagram

invoke options

Script XML

<script>
    <invoke service="VPN" timeout="1500"/>
    <invoke service="HomeZone"/>
    <invoke service="Prepay" on-timeout="terminate-processing"/>
</script>

Attributes and child elements

Below are possible attributes and child elements for an <invoke> element

Attributes

Name Description Optional?
 service

The service to be invoked. Must refer to a service defined in the SIS (using a service reference).

 timeout

Specifies the timeout period, measured in milliseconds, that the SIS will wait for a response from the service when required. If present, this timeout overrides the default timeout configured for the service.

 on-timeout

Specifies the behaviour the SIS will take if a service response timeout (or other service failure) occurs at any time for the invoked service. The supported values for this attribute are:

  • ignore-service-and-continue — remove the service from further interaction with the composition and continue delivery of any current event to the next service

  • terminate-processing — terminate processing of the current event; if no terminate child element is specified then, if relevant, the SIS will send a response to the network based on event processing thus far, otherwise the SIS will take the action specified by the terminate element.

Warning The behaviour of the terminate-processing action with no terminate child element changed between SIS 2.4.0 and SIS 2.5.0. Please refer to the change log included in the distribution package for information on the previous behaviour and how that behaviour can be specified in the composition.

The default value if this attribute is not specified is ignore-service-and-continue.

Child elements

Name Description Optional?
 service-input-interceptor

A service input interceptor. The SIS evaluates this input interceptor before it delivers any event to the service.

 service-output-interceptor

A service output interceptor. The SIS evaluates this output interceptor whenever the service generates output intended for the network.

 terminate

This element can only be specified if the on-timeout attribute is set to terminate-processing. It specifies a terminate clause that the SIS will use to send a response for the current event.

 message-handling-options

This element specifies configurable options for how the SIS manages specific messages received from the service.

 extension-options

Specifies arbitrary extension options supported by the SIS for service invocation. This is a collection of extension-option elements each with a name and optional value. See the extension options currently supported for <invoke> elements.

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