Service input and output parameters are defined within the Service's definition using XML declaration statements with an element tag of attribute. Each XML attribute element declaration represents either an input parameter (INPUT), an output parameter (OUTPUT), or a parameter that is passed as both input and output (INOUT). The participation of each parameter as an input or output value may be made optional by adding an optional attribute to the declaration. By default, the optional value is false, and all parameters that are defined are required to be passed. This means that the Service will fail if one or more of the configured (non-optional) parameters are not passed.
Note
Note: If an INPUT parameter is not defined for a Service, then that value will not be passed into the Service's execution context regardless of the values that are sent by the calling program. Similarly, if an OUT or INOUT parameter is not defined for a value, then that value will not be passed back to the calling program.
Add one or more attribute elements within the Service definition. For example:
<service name="myService" engine="SupportedEngine" location="somewhere.on.the.classpath" invoke="myService"> <attribute name="attribute1" type="String" mode="IN" optional="true"/> <attribute name="attribute2" type="String" mode="IN" optional="false"/> <attribute name="attribute3" type="String" mode="INOUT"/> </service>
The OFBiz Service Engine handles the passing of input, output, and context parameters automatically based on the Service's Service definition. Only parameters configured for the Service (and several OFBiz managed context parameters such as the userLogin GenericValue, locale, timeZone, errorMessage, and errorMessageList) will be passed as input or as output.
By default, OFBiz automatically validates, at runtime, all incoming and outgoing parameters against the defined type attribute as configured. Validation failures will cause the Service to fail and control will be passed back to the calling program.