More about data transforms
Using a data transform, you can specify initial properties for objects of a specific class and also map properties (and their values) of an instance of a class to an instance of a different class.
For example, you can ensure that a special set of risk-related properties is present on all instances of class Data-Loan-Aircraft-SingleEngine. When a page of this class is created, you can instruct the system to apply a data transform, named Aircraft-High-Risk. The system places into the page the risk-related properties defined in the data transform. When the page is later saved into the database as a persistent instance, the properties are present with meaningful values.
Typically, you use the actions within a data transform to update and apply data to clipboard pages. Additionally, there are four activity methods that can optionally use a data transform as a parameter:
- Apply-DataTransform — Updates existing clipboard pages with values computed from a data transform.
- Page-New — Creates a new named page of a specified class. If a data transform is specified in this method, the data transform's actions are applied to the page.
- Page-Copy — Copies the contents of a clipboard page to a new named page or replaces the contents of an existing page. If a data transform is specified in this method, the data transform's actions are applied to the destination page before the source's contents are copied.
- Page-Change-Class — Creates a new page of the specified class, and then copies properties from another page into it, according to the method's Keep parameter and the specified data transform (if any).
The Apply-Model method is deprecated in version 6.2, and replaced by the
Apply-DataTransform method. To use the Apply-DataTransform method to achieve the same result
of using the Apply-Model method with the OverwriteProperties parameter set to
'false', use When actions in the data transform to prevent values from
being applied when properties are already present on the target page. For example:
When !@PropertyHasValue(.FirstName) Set .FirstName = "Bob"
In the preceding example, when the
property has a value, the
condition is not satisfied and the Set action is skipped.
Service rules ( Rule-Service- classes) and a few other rule types can reference a data transform. The data transform is processed and applied at runtime to a newly created page.
Viewing the Java code of a rule
Clickto view the generated Java of a rule. You can use the Java code to debug your application or to examine how rules are implemented.
Changing the value of a TimeOfDay property
When you use an expression on TimeofDay property type values, the expression converts the value into a BigDecimal where the whole number is the number of days and the fraction is the hour of the day expressed as a fraction of a day, for example, 12 hours is 0.5 (half of a day). The format is useful to know when you want to change the value of a property that is a Date, DateTime, or TimeofDayproperty type.
For example, assume that you have a property of type TimeofDaythat is formatted as a standard time with hour, minute, and second without punctuation. To add 12 hours to the property:
- Use a Set action to assign the property value to a second property that is of type TimeofDay.
- On the right side of the expression, enter the property reference plus the fraction. In this example, enter .5 to add 12 hours.
ArticleConstants in expressions