Creating and Managing Decision Tables

Decision Tables are provided to easily manage business rules in a familiar spreadsheet format. Decision tables exist within the context of a Rules Set. Multiple decision tables may exist within a Rules Set, which may also contain Rules. In the Decision Table Editor you can create and manage decision tables.

The tables may be created directly in the editor or imported into the editor from a spreadsheet format.

• Table Content
• Adding Decision Tables
• Editing Decision Tables
• Renaming Decision Tables
• Deleting Decision Tables

Table Content

A Decision table may contain the following entries:

• Description column - optional text description for the rule in the according row. This column exists per default and cannot be deleted.
• Attribute columns -
  • optional rule attributes (e.g., salience, timer, enabled, etc.)
  • lock-on-active - this column exists per default with the value true for the whole table. This allows each rule to only fire once by default. Note that disabling the attribute can easily lead to infinite loops and is only necessary if one rule should fire as result of another rule. For example:
    A rule sets Person.age to 18 and a second rule should react to Person.age >= 18 and sets driversLicense = true.
  For details on provided attributes refer to section Available Rule Attributes.
• Condition columns to define conditions on properties of objects in the Rules Data Set. For details on adding conditions, refer to section Adding conditions.
• Action columns to define the rule action for the consequence of the rule. For details on adding actions, refer to section Adding actions.
• Rows for Rules specifying values for the properties set in the Action column

The headers for individual Attribute, Condition and Action columns have an additional label containing the name of primitive used. The operator used in each condition is displayed next to it. Hovering over the header displays the entire path of the data.

Figure: Header Tooltip

These columns can be reordered via drag-and-drop, but only in relation to columns of the same type.

Available Rule Attributes

The following rule attributes are available:

Lock-on-active Attribute Column

The lock-on-active attribute column exists per default with the value true for the whole table. This allows each rule to only fire once by default.

Note
Take attention when disabling the lock-on-active attribute. This can easily lead to infinite loops!

The following warning is displayed above the decision table in case of any change of the lock-on-active column:

Figure: Warning message

Disabling the attribute is only necessary in a scenario where one rule should fire as result of another rule, as in the following example:

A rule sets Person.age to 18. A second rule should react to Person.age >= 18 and set driversLicense = true. In that case the second rule needs to fire as result of the first rule.

Figure: Exception example for using disabled lock-on-active attribute

Adding Decision Tables

To add a decision table, right-click a Rules Set node in the Outline and select Create Decision Table.

Figure: Adding a Decision Table

A new decision table node is added to the Rules Set and the Decision Table Property view opens.

Figure: New Decision Table

The view displays the following entries:

• UUID and ID of the Decision Table
• Decision Table Name - Please enter a name for the new Decision Table
• Description - optionally enter a description for the Decision Table

Editing Decision Tables

If a new Decision Table is added, the properties view of the Decision table opens automatically. To edit an existing Decision Table, click the according Decision Table node in the My Rule Sets tree.

• Adding Columns
• Hiding Description and Attributes
• Searching for Text Occurrence in the Table
• Setting Operators in the Table Header
• Managing Rows and Columns

Adding Columns

To add a column, click the Add column icon in the Decision Table toolbar.

Figure: Adding a column from the toolbar

The Add Column dialog opens. You can add attributes, conditions and actions.

• Searching for attributes, Structured Types and Primitives
• Adding attributes
• Adding conditions
• Adding actions

Searching for attributes, Structured Types and Primitives

A search facility is provided to find attributes, Structured Types and Primitives in the tree. All search hits are highlighted, and the tree is auto-expanded to reveal search hit nodes that may be hidden.

Figure: Searching in the tree

Adding attributes

To add rule attributes to a Decision table, expand the Attributes node in the Add Column dialog and select one of the provided attributes, which are described in section Available Rule Attributes.

A tooltip is displaying the description for a specific attribute, e.g.:

Figure: Tooltip showing description for attribute

For details on rule attributes in general, you can refer to the JBoss Rule Language documentation.

A separate attribute column is created for each attribute selected from the list. Note that only one attribute can be selected for a table. An already added attribute is grayed out in the tree and not selectable again.

Adding conditions

To add conditions to the decision table, expand the Conditions node in the Add Column dialog and select the conditions that you want to add. Optionally, you may search for the conditions you want to add in the search box, as described in section Searching for Structured Types and Primitives and select them from the highlighted search results.

All IN data defined in the containing Rule Set are displayed in a tree structure under the Conditions node. Structured Types are represented with the icon, may be expanded to display their primitive leaf nodes.

Figure: Adding Conditions

The following rules apply to selecting Conditions:

1. Only primitives (represented with the icon) can be selected
2. Multi-cardinality fields cannot be selected, these are hidden
3. The same primitive can be added multiple times

Adding actions

To add actions to the decision table, expand the Actions node in the Add Column dialog and select the actions that you want to add. Optionally, you may search for the actions you want to add in the search box, as described in section Searching for Structured Types and Primitives and select them from the highlighted search results.

All OUT data defined in the containing Rule Set are displayed under the Actions node in the tree.

Figure: Adding Actions

The following rules apply to selecting Actions:

1. Only primitives (represented with the icon) can be selected
2. Multi-cardinality fields cannot be selected, these are hidden
3. Only primitives that are not used in the decision table in scope are visible
4. Primitives are enabled in the tree once they are added to the table

When a primitive is selected, a new action column is immediately added to the decision table for that primitive.

Hiding Description and Attributes

To hide the Description and Attributes columns in a Decision table, click the Hide Description and Attributes icon in the table toolbar.

Searching for Text Occurrence in the Table

To search for a text occurrence in the decision table, enter a text snippet in the Search entry field in the toolbar. All fields in the table that match are highlighted.

Figure: Searching for Text in the Table

Setting Operators in the Table Header

For Condition columns, the operator can be changed by clicking the operator label. A drop list is populated with the operators specific to the column primitive data type.

Figure: Choosing an operator

The following operators are provided according to the data type:

Operator Icon	Description	Code Usage Example	Supported for Type
			Boolean	String	Numeric	Date
	Equal To	==	X	X	X	X
	Not Equal To	!=		X	X	X
	Greater Than	>		X	X	X
	Less Than	<		X	X	X
	Less Than or Equal To	<=		X	X	X
	Greater Than or Equal To	>=		X	X	X
	Matches	matches		X
	Sounds Like	sounds like		X
	Null	= null		X	X	X
	Not Null	!= null		X	X	X
	In List	in ( "a", "b", "c" )		X	X	X
	Not In List	not in ( "a", "b", "c" )		X	X	X
	After	Date after "19-Sep-2013"				X
	Before	Date before "19-Sep-2013"				X
	Coincides	Date coincides "19-Sep-2013"				X

Managing Rows and Columns

Rows and columns can be managed by a context-menu that appears when right-clicking in the according table cell.

• Removing Columns
• Moving Rows
• Removing Rows
• Inserting Rows

Removing Columns

To remove a column, right-click in the column and select Remove Column.

Figure: Deleting a Column

Moving Rows

To move a row up or down in the table, right-click the according row and select Move Row Up or Move Row Down accordingly.

Figure: Moving a Row inside the Table

Removing Rows

To remove a row, right-click the according row and select Remove Row.

Figure: Deleting a Row

Inserting Rows

You can insert rows in the table directly. Right-click a row in the table and select one of the following options:

• Insert Row (Above)
• Insert Row (Below)

Figure: Insert a Row

To append a row at the end of the table, click the Add Row icon in the table toolbar.

Figure: Adding a row from the toolbar

Renaming Decision Tables

You can rename a Decision table by one of the following actions:

• Right-click the Decision table in the My Rule Sets tree and select Rename

  

  or
• edit the Name field in the properties view of the Decision Table.

  

Deleting Decision Tables

To delete a Decision Table from a rule set right-click the table in the My Rule Sets tree and select Delete.

Figure: Deleting a Decision Table

A confirmation dialog opens to confirm the deletion of the table.

Figure: Deletion Confirmation Dialog

All open views respective to the deleted Decision Table will be closed.