Decision Table form
Completing the Table tab

Button

Function

Insert a new row before (above) the selected row.

Insert a new row after (below) the selected row.

Delete the selected row or rows. Focus moves to the row above.

Insert a new column before (to the left of) the selected column.

Insert a new column after (to the right of) the selected column.

Delete the selected column or columns. Focus moves to the column at its left.

Insert OR'd tests in one cell, to the left of the current test.

Insert OR'd tests in one cell, to the right of the current test.

Insert a column in the Actions area to the right of the Results column, to set a property to the results of an expression when this row is the source of the decision table results.

Hide (or show) the properties columns in the Actions area.

Button

Function

Show Conflicts

Marks with a warning icon () any rows of the table that are unreachable, and any rows that are completely blank. For example, if two rows are identical, the second row will never evaluate to true and so is unreachable.

If the Evaluate All Rows check box (on the Results tab) is selected, all rows are considered reachable.

Click any warning icon on a row to highlight with an orange background (      ) the other rows that cause that row to be unreachable. The selected row is highlighted with a pale yellow background (      ).

In this example, the third row is unreachable and the value 3 is never returned. The first two rows together make the third row unreachable.

A decision table that contains no such unreachable rows is called consistent. (The presence of unreachable rows does not prevent you from saving the rule.)

Conflicts are reported as warning messages when you save the form and when you use the Guardrails landing page for the application.

Conflicts do not prevent the rule from validating or executing, but may indicate that the rule does not implement the intended decision.

Show Completeness

Appears on the Table tab when the matrix of values is displayed. Automatically adds suggested rows of the decision table that cover additional cases and reduce or eliminate the situations that fall through to the Otherwise Return expression. They are only suggestions; you can alter or eliminate them.

When a table has more than 500 cells, the matrix is not automatically displayed on the Table tab. To display this button for such a table, display the matrix of values by clicking Load Table in Rule Form.

Edit in Excel

Edit the contents of the table using Microsoft Excel. By design, you can't use Excel sort capabilities, because the order of rows in the decision table is significant.

Load Table in Rule Form

Display the values for a table with more than 500 cells. By default, the system does not display the matrix of values for tables with more than 500 cells.

To check the completeness of a decision table with more than 500 cells, first display the matrix by clicking Load Table in Rule Form, and then click Show Completeness.

Remove Table from Rule Form

Appears after you click Load Table in Rule Form and the matrix of values is displayed on the Table tab. Click to remove the matrix from the rule form tab.

Field

Description

Enter the condition you want to evaluate. This may be a Single Value property, a property reference to a single value, a linked property reference, or a more complex expression. Use SmartPrompt to see a list of all the properties available in the Applies To class of this decision table (and in its parent classes).

Click () to start the Expression Builder. See About the Expression Builder. (You can enter complex expressions and use the Expression Builder only when the Allowed to Build Expressions? check box is selected on the Results tab.)

You can add or modify a property value by dragging an instance from the Application Explorer and dropping it on the Property field. The rule name populates the Label field. Click the icon to select the rule.

Enter a text label for the column.

Select to require two values defining an open or closed range for the column. Choose the < or <= operator to test the starting value. Choose the > or >= operator to test then ending value. In each cell, enter two values to set the limits of the range.

Select an operator for the comparisons in this column. The default is equality (=). If you choose an operator other than =, the operator appears in the column head. An operator in a cell can override the operator you select here, for that cell.

Field

Description

Select a radio button to control who can change the contents of cells in this column. The column background changes to gray for users who cannot update it.

• Everyone — Anyone who can edit the table can change the contents of cells.
• No one — No one (including you) can change the contents of cells.
• Privilege — Any user who holds the selected privilege can change the contents of cells. Select a privilege in the Applies To class of this rule, or in an ancestor class.

This field is not available to users who are delegated this rule.

Field

Description

Define in each row the conditions to be met for each cell. At runtime, the row evaluates to true only if the conditions in each cell evaluate to true.

The label when in this column indicates that at runtime, decision table processing evaluates all rows, rather than stopping at the first row for which all conditions are met. The label appears when you click the Evaluate All Rows option on the Results tab.

Enter a match value for the property identified at the top of each column. Alternatively, enter a comparison operator and an expression, such as a literal value, property reference, or linked property reference. The comparison operators are <, >, =, <=, >=, and !=. If you don't enter an operator, the system uses the operator or operators associated with the column head. (The equality operator = does not display in the column head.)

For columns that require a range, enter both a starting value and an ending value. If you enter literal constants for these values, check that the starting value is less than or equal to the ending value.

You can use SmartPrompt to access a Local List of values (if any) defined on the Table Type fields on the General tab of the property. Do not type a period. For example, if the property Size has values such as XS, S, M, L, XL, and XXL defined, click the Down Arrow key to access this list.

To the right of the comparison operator, enter a literal constant, a property reference, or an expression. For guided assistance in entering expressions, click the magnifying glass icon () to start the Expression Builder. (You can enter complex expressions and use the Expression Builder only when the Allowed to Build Expressions? check box is selected on the Results tab.)

To add more rows, click the Insert Row After button () to the left of the row. Another row appears, titled else if.

As a best practice to simplify the form, delete any blank rows. They cause a warning when you save the Decision Table form. Blank rows have no effect on the results of the rule.

Field

Description

Enter the result to be returned to the application when all the comparisons in the row are true. Enter a constant, a property reference, an expression, or the keyword Call followed by a space and the name of another decision table.

You can enter values in this column only when the Allowed to Return Values check box is selected on the Results tab.

Optional. If you used the button to create a column to the right of the Return column, enter a constant value, property reference or expression here, or use one of three shorthand forms:

• Enter a +=1 in the cell to cause the system to add 1 to the current value of the property.
• Enter += or -= followed by a numeric constant to add or subtract a constant value to from the current value of the property.
• Enter -= and a text constant to append a constant value to the current value of the property (assumed to have a Type of Text or Identifier).
• Enter /= for division, *= for multiplication, or %= for the remainder function.

For guided assistance in entering expressions, click the magnifying glass icon () to start the Expression Builder. (You can enter complex expressions and use the Expression Builder only when the Allowed to Build Expressions? check box on the Results tab is selected.)

The system evaluates this expression when the decision rule returns based on the current row. The results of the evaluation are set as the new value of the property identified in this column.

Field

Description

This check box appears only for decision tables that are circumstance-qualified. When selected, causes PRPC to execute the base (or non-qualified) decision tree of the same name, RuleSet, and Version to obtain the result.

Enter the result to be returned to the application if none of the rows in the table evaluate to true.

Enter a constant, a property reference, or the keyword Call followed by a space and the name of another decision table. If results are restricted to those values listed on the Results tab, select from the choices presented.

You can enter values in this field only when the Allowed to Return Values check box is selected on the Results tab.

If this field is blank and no return value is computed from higher rows, the system returns a null value.

During backward chaining computations for Declare Expression rules, if the Otherwise value can be computed, but properties needed for other parts of the form are not defined, the Otherwise value is returned as the value of the decision table. (In PRPC releases before 5.3, this condition produced an exception that ended processing.)