Guards are Boolean expressions that must evaluate to "true" before the task is activated.
The expression may be based on the current values of workflow variables, on resources in
the Content Management Server or on external resources. A possible use of
guards is to determine the resources that are required for the task. The task then is
deactivated until all resources are freely available. Thus, the workflow suspends
execution until the guard is fulfilled.
In Example 4.7, “Example of a Guard” you see a guard that checks whether the
property isCheckedOut_ of the resource contained in the variable "document"
(variable="document") is set to false (the stored value is negated by
Not). That is, the task continues when the document is checked in.
<Guard> <Not><Read variable="document" property="isCheckedOut_"/></Not> </Guard>
Example 4.7. Example of a Guard
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