Creating derived attributes

You can create an attribute that derives its value from other attributes instead of directly from the data source. In the derived attribute, you can perform operations on the values of the source attributes, such as basic arithmetic operations on numeric attributes or string concatenation on string attributes.

The basic expression syntax used for derived expressions contains functions. These functions provide a more complicated manipulation of data including short term aggregation, conversion from string to integer, and accessing configuration properties and environment variables. In addition, an editor helps you visualize the expression as it is being built.

To add a new derived attribute, use the following procedure:

1. On the Data Source Definition page, right-click the data source and click Add Attribute.
   Figure 45. Adding an attribute

   
2. On the Attribute Information page, type an Attribute name and Help text (Figure 46).
   Figure 46. Attribute Information page

   
3. Click the Derived Attribute Details tab to create an attribute that derives its value from other attributes instead of directly from the data source.
   Figure 47. Attribute Information page with Derived Attribute Details tab open

   
4. In the Formula field, type the formula text or click Edit to enter the formula with a graphical editor. See Formula operators and functions for information about the operators and functions that can be used in the formula.
   Note:

   When you click Edit, the Derived Formula Editor is displayed. See Editing derived attributes for information about editing derived attributes.
5. In the Attribute type area, click the type of attribute.
6. Click OK. The Data Source Definition page is displayed again with the data source listed in it as before (see Figure 91).
7. Click Finish.