Derived and Stored Properties
Derived and Stored properties are properties whose default value is calculated during a request from an expression that you define and then stored on the node when a request is completed.
Derived and Stored default property values are indexed so that they can be referenced when querying viewpoints. See Querying a Viewpoint. You can also use them to derive a value for a property in a hierarchy viewpoint and then access that stored value for the property in a list viewpoint.
Note:
Properties with the Derived and Stored default type are able to be queried only after a value has been either defined or derived and then stored for that property on a node. This is true even if you join the Derived and Stored query filter with an indexed property query filter using an AND statement. See Querying a Viewpoint.Considerations
- You can derive and store default values for node level properties only.
- You cannot derive and store default values for properties in the Core or CoreStats namespaces, or for properties with the Sequence data type.
- You can set the Derived and Stored default type at the application and node type levels in the property inspector. See Editing Property Parameters.
- Derived and Stored property values are processed during a request, an import, or when loading a viewpoint.
- You can clear the current value of a derived and stored default value in order to
derive and store the value again:
- For interactive requests, in the property that you want to clear and derive
again click Actions
, and then select Clear.
- In a request file upload, use the
<clear>
keyword. See Request Load File Format.
- For interactive requests, in the property that you want to clear and derive
again click Actions
Defining a Derived and Stored Property
-
Inspect a property definition that uses a Boolean, Date, Float, Integer, List, Node, or String data type. See Inspecting Properties.
-
Select an application or a node type, and then click Edit.
-
From Default Type, select Derived and Stored.
-
Click the Expression icon in the Default Value text box.
-
Define an expression to calculate the property and click Apply. For information on how to define expressions, see Using Expressions to Define Custom Business Logic.
Note:
If you change the Default Type from Derived to Derived and Stored (or the reverse), you do not have to re-enter the expression to calculate the property value. -
Click Save.