Fragments

As you create rules, you must create rule fragments that perform the rule logic. This section describes in detail how to create and work with rule fragments.

Working With Rule Fragments

Use these procedures to define or modify a rule's fragments when you are creating ( To Define a Rule) or modifying ( To Modify a Rule) a rule.

When you are creating a rule, the Fragment area appears as in Figure 336.

TABLE 35. Rule Buttons 

Button	Name
	New Operator button
	New Fragment button
	Delete button
	Edit button

Click the New Fragment icon here to create a fragment at the currently displayed level (in this case, the top level) in the rule structure. Click New Fragment again to create a second fragment at the currently displayed level. In other words, the rule would be:

FragmentA AND FragmentB

Clicking the New Operator icon creates a nested level for creating fragments, as shown in Figure 337. The new level displays a new set of New Fragment and New Operator links. You use this New Fragment link to create the fragments at this nested level. If you click New Operator at this level, then you will create another nested level below this one with another set of New Fragment and New Operator links for that level.

Example: To Create a Simple Level of Fragments

In this example, you are attempting to create a rule consisting of two fragments, joined by a single operator, with no nested levels: FragmentA AND FragmentB. When you access the tab, the New Rule tab appears as in Figure 338.

1. Select the boolean operator you want for these fragments.
2. Click the New Fragment icon

   This displays the New Fragment tab.

3. Define the fragment.
   1. Check the Not check box if you want to define the fragment as a negative: "NOT (sum(PropertyA <= 250))".
   2. Select the first function from the Function1 drop-down list.

      See Table 12, Function Definitions.

   3. Select a property from the Property1 drop-down list.
   4. Select the operator.

      See Table 13, Operators.

   5. Select the second function from the Function2 drop-down list.
   6. In the Property2 field, select a property from the drop-down list or enter a literal value in the field (if you selected "literal" as the function).
   7. Select the value for the If Not Specified drop-down list.

      See If Not Specified for an explanation of these values.

4. Click Save and Return.

   This re-displays the New Rule tab with the new fragment, as shown in Figure 340. Also, notice the infix representation.

5. Click the New Fragment icon to create the next fragment in the rule.
6. Repeat Step 3 to define the second fragment.
7. Click Save and Return.

   This re-displays the New Rule tab with the fragment you created, as shown in Figure 341. Notice that the rule has two fragments now.

You can click Save to save the rule and continue defining the rule. Click Save and Return to return to the list of rules in the Define tab.

Example: To Create Nested Fragments

In this example, the modeler is creating the following rule with nested fragments:

(FragmentA AND FragmentB) OR (FragmentC AND FragmentD)

1. Click New Operator icon.

   A nested level appears in the New Rule tab, as shown in Figure 343. This level has its own drop-down boolean operators, as well as its own New Fragment, New Operator, and Delete Operator icons.

2. Create two fragments as described in Example: To Create a Simple Level of Fragments.

   Use the nested drop-down list to select the boolean operator for these fragments. The default is AND.

   Use the nested New Fragment icon to create the fragments at this nested level.

   When the two fragments are completed, the New Rule tab appears as in Figure 344.

You can nest as many fragments as you want by clicking the nested New Operator icon. Each time, a new nested operator will appear with a new set of nested icons. You use these nested icons to create the fragments for the nested level.

3. Using the top-level list, select the boolean operator (in this example, OR) that will join the two nested levels.

4. Click the New Operator icon at the top level.

   A new nested level appears in the fragments tab, as shown in Figure 346. This level has its own drop-down boolean operators, as well as its own New Fragment, New Operator, and Delete Operator icons.

5. Create two fragments as described in Example: To Create a Simple Level of Fragments.

   Use the nested drop-down list of boolean operators and the nested New Fragment icon for these fragments.

   When the two fragments are completed, the New Rule tab appears as in Figure 347.

To Modify a Fragment

1. Find the fragment you want to modify, then click on the Edit Fragment icon in the Actions column.

   This displays the Edit Fragment tab.

2. Modify one or more elements of the fragment.
   1. Check the Not check box if you want to define the fragment as a negative: "NOT (sum(PropertyA <= 250))".
   2. Select the first function from the Function1 drop-down list.

      See Table 12, Function Definitions.

   3. Select a property from the Property1 drop-down list.
   4. Select the operator.
   5. See Table 13, Operators.
   6. Select the second function from the Function2 drop-down list.
   7. In the Property2 field, select a property from the drop-down list or enter a literal value in the field (if you selected "literal" as the function).
   8. Select the value for the If Not Specified drop-down list.

      See If Not Specified for an explanation of these values.

3. Click Save And Return.

To Delete a Fragment

Find the fragment you want to delete in the Fragments table, then click the Delete icon in the Actions column on the same line as the fragment.

Working with Rule Actions

Perform these tasks when you want to include a rule action when you are creating ( To Define a Rule) or modifying ( To Modify a Rule) a rule.

You define rule actions in the lower part of the New Rule or Edit Rule tab. Rule actions comprise three types of actions:

• Message Actions: A message that is displayed when the rule is triggered.
• Expansion Action: Defines an expansion action based on a rule expansion formula.
• Assignment Action: Assigns the value calculated by the rule formula to one or more properties when the rule is triggered.

To Create a Message Action

When you are creating ( To Define a Rule) or modifying ( To Modify a Rule) a rule, you perform this task in the Message Actions area of the New Rule or Edit Rule tab.

1. Select the type of message action from the drop-down list: Error, Warning, Suggestion.
2. Type the message.
3. Click Add Item.
4. Repeat these steps to enter additional messages.
5. Click Save to save the message action and continue editing. Click Save and Return to save the message and return to the Define tab.

To Create an Expansion Action

When you are creating ( To Define a Rule) or modifying ( To Modify a Rule) a rule, you perform this task in the Expansion Actions area of the New Rule or Edit Rule tab.

1. Enter a formula. The formula can use the supported functions as described in Rule Fragments.

   The results of formula will be used to perform the expansion. See Expansion for an explanation of rule formulas.

2. Enter a minimum and a maximum amount of the formula result.

   The minimum amount is the minimum value the rule formula result must be greater than. This value can be negative or greater than or equal to zero. The value must be less than the maximum value (Max). The maximum amount is the maximum value the rule formula result must match. This value must be greater than the minimum value (Min).

   Note:

   Min and Max work slightly differently: for a fragment to evaluate to true, the rule formula must evaluate to greater than the Min value, but less than or equal to the Max value.

3. Enter the quantity of the expansion items (must be greater than zero). You can use the supported functions to calculate the quantity and so you can specify the quantity as a function of a property. For example:

   2*value(Memory Cards)

4. Enter the item that will be expanded.

   You must provide the full path to the expansion item within the current model. In the figure above, for example, the rule adds an option item called either 64MB, 128MB, or 256MB, located in option class AutoMemory in the current model.

When a rule is used in multiple models, this fully qualified path could be difficult to specify since the current model name will very likely not be "MXWS-7650" for all the models where the rule is attached. To facilitate the use of expansion rules across multiple models, you can usual special symbols as follows:

• You can begin the path with a period (.), which means "from the attachment point of the rule". In other words, if you attach a rule to a model, then ".Memory.64MB" means "an option item called 64MB in an option class called Memory in the current model".
• You can begin the path with an asterisk (*), which means from the root of the model group hierarchy.
• If the name of a path component includes a quote character (' or "), then you must escape the quote character or wrap the whole expression in quotes. For example, to get the gauge property from the Tubing.3"pipe.threading option item, you can use

  		x = value(Tubing.3\"pipe.threading.gauge)

  or

  x = value('Tubing.3"pipe.threading.gauge')

  To retrieve Board.8'plank.thickness, use

  x = value(Board.8\'plank.thickness)

  or

  x = value("Board.8'plank.thickness")

5. Repeat these steps to enter additional items.
6. Click Save All Changes.

Typically, the result of an expansion action is to pick a quantity selected on an option item. If the option item quantity is a drop-down list, then you should take to ensure that the possible calculated values are consistent with the pickable values: otherwise, the drop-down list will not be able to display the calculated value.

To Create an Assignment Action

When you are creating ( To Define a Rule) or modifying ( To Modify a Rule) a rule, you perform this task in the Assignment Actions area at the bottom of the New Rule or Edit Rule tab.

1. Select a property from the drop-down list. The table below summarizes some of the special properties that can be assigned.
2. Enter a value for the property. You can use the supported functions to calculate the value and so you can specify the value as a function of a property. For example:

   2*value(Memory Cards)

   When you are assigning a value to a property whose type is String, then you must use the following syntax to refer to properties:

   ${function(arg1, arg2, ..., arg N}

   For example, ${expand("Color", "Black", 0)}. See Example Uses of Expand for other examples of the usage of the expand function.

3. Type the entity to which you want to assign the property and its value.

   If you leave this field blank, then the assignment defaults to the entity to which the rule is attached.

4. Click Add Item.

5. Repeat these steps to add additional items.
6. Click Save All Changes.

The following table summarizes some of the available properties for assignment. These properties can be changed each release so check with your Comergent Technologies representative for further information if required.

TABLE 36. Assignment Action Properties

Property	Action
_constraintMessage	String: a message on an item because it is constrained
_constraintType	Integer: type of constraint; 0 is suggest, 1 is warn, and 2 is error
_description	String: an items description
_amEntitled	Integer: 0 false, 1 true
_isConstrained	Integer: 0 false, 1 true
_isSelected	Integer: 0 false, 1 true
_isViewable	Integer: 0 false, 1 true
_itemKey	Integer: database key of the item
_pickOverride	Integer: 0 false, 1 true; pick was overridden by a rule
_quantity	Integer: quantity; 0 quantities are not in the rule pool
_ratio	Numeric: ratio of this item to its children, computed if nested within another parent
_rawRatio	Numeric: raw ratio used in previous computation
_rulePick	Integer: 0 false, 1 true
_tabLevel	Integer: depth of this item

Example Uses of Expand

The syntax of the expand function should follow ${expand(property[,defaultValue[,format[,lookup]]])}.

For example, suppose that you want to display the name of the model as the name of the associated product together with the product description. Then at the model level, set the value of the UI: DISPLAY NAME property to: ${expand("UI: PRODUCT NAME")} or ${expand("UI: PRODUCT DESCRIPTION","Description not available")}.

This has the advantage that if the product name or description gets changed, then if you recompile the model, then the name or description is displayed with the new version when users next configure product.

Here are some further examples of the expand function:

• String-valued property
  • ${expand("color")}
  • ${expand("color", "Black")}
• Numeric-valued property
  • ${expand("weight")}
  • ${expand("weight", 0.0)}
  • ${expand("weight", 0.0, #.00)}

Comergent Technologies http://www.comergent.com Voice: (650) 232 6000 Fax: (650) 232 6010 support@comergent.com sales@comergent.com