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Completing the Definition tab

 About Model rules

Use the Definition tab to list the properties and values to include in the model.

At runtime, the system makes the property assignments in the order of the rows. A property reference in a row can refer to a property (as a source of value) that is computed in a higher row.

Select the Call superclass model? check box to chain together this model and a model in the immediate parent class of the same Model Name. At runtime, the system sets properties and values defined in the parent class first. (If the parent class model also has this check box selected, its own parent's model is used first, and so on.)

TipIf this model is to be used to initialize a newly created page, do not set properties to the null value (or empty string ""). This has no effect on later computations involving the property, as the PropertyExists() function returns false for such properties, and properties with a null value are not saved into the PegaRULES database by the Obj-Save method. (Models that apply to a class derived from the Rule- base class are exceptions, because null values are important to runtime forms created by the Form Builder.)

Field

Description
Data Dictionary Entries  
Property

SmartPrompt zzzSpecify a target property or property reference to be initialized. See How to reference properties. Click the pencil icon (zzz) to open the property rule.

To convert this row into a non-functioning comment, precede the property reference with two forward slash characters (//).

Value

Optional. Enter an expression. See About Expressions. If you use an expression that references a value on a page other than the page being updated, list that page name and class on the Pages & Classes tab.

TipTo enter literal constants that represent a Date (as "20051215") or DateTime value, remember to include double quotes to distinguish them from integer constants.

TipDon't use "" as a value to initialize a property of type TrueorFalse. Use "T" or "F" for true or false values respectively.

For guided assistance in entering complex expressions, click the magnifying glass icon (zzz) to start the Expression Builder.
Super Class Model  
Call superclass Model?

Select to cause the system at runtime to apply a model of the immediate parent of this model's class (with the same Model Name) before it applies this model.

This approach can link together several models. This capability is sometimes described as model chaining. The model that is found may (through this check box) refer to still another model of this name, in a still-higher class.

Click the pencil icon (zzz) to open the model of the superclass.

Note the details of the internal algorithm for this feature:

  1. Process Commander identifies the parent of the current class using the Parent field in the class definition, not by following full class hierarchy searches. (Thus, it uses directed inheritance first to find the parent, then pattern inheritance.)
  2. After identifying a parent class, the system uses rule resolution to find the model of the same name as the current model.
  3. The model in the highest class is applied first. The current model is applied last.

For example, assume a model named FirstModel in the class Master-MyDesign has this box selected. The system examines the Rule-Obj-Class instance named MyDesign to locate its parent class (say Data-Master-). It then uses rule resolution to find another model named FirstModel, starting with the Data-Master- class. The rule resolution search depends on the user's RuleSet list, versions, time-based rules, circumstances, and so on.

zzz About Model rules