About Value Assignment

Values are held in variables that exist for the entire execution of an orchestration workflow. These variables include the following:

• Working data variables
• The asynchronous orchestration workflow EventNotice or the synchronous orchestration workflow EventNoticeWithReply and EventNoticeWithReplyResponse
• Request and response messages for each Service step in the workflow

A working data value can be assigned on the Data Mapping tab in the orchestration workflow Property Editor. Alternatively, a Calculate step can be used to assign a value to a working data variable.

The EventNotice or EventNoticeWithReply variables will contain the values sent when the orchestration workflow is invoked, but can be overwritten by Calculate steps. The EventNoticeWithReplyResponse can be assigned using the Data Mapping tab in the End step Property Editor.

A Service step input variable can be assigned on the Data Mapping tab for the step or by a Calculate step that specifies the input to a Service step as its target. A Service step output variable is normally assigned by the Service step on its return. However, a Calculate step can be used to set or override a value in the Service step output variable.

The Data Mapping tab includes a Source elements column, where values are mapped from other variables. It also includes a Default value column, where a constant value can be specified.

Values are assigned to Service steps as follows:

1. When an orchestration workflow is invoked, its first action is to allocate the event variables, the working data, and the Service step input and output message variables. It does this by assigning any default values that have been specified. Its next action is to perform mappings to working data, overwriting any default values with the respective mapped values.
2. When the workflow reaches a Calculate step, values assigned by that step replace either the initial values as described above or the values set by previous Calculate steps.
3. When the workflow reaches a Service step with mappings, the mappings replace either the initial values as described above or the values set by previous Calculate steps.

A data element with a complex type has a structure that includes a parent element and child elements. When you map a parent element to a source parent element, its child elements are replaced by a copy of the source child elements. Because the mappings copy the source data structure, you can explicitly assign different values to the child elements in the new structure without changing values in the parent. For details about complex types, see About Complex Types and Namespaces.