Administration > Working with the Type and Attribute Management Utility > Managing Types > Attribute Information Page > Constraints Tab > Attribute Constraint Rules
  
Attribute Constraint Rules
The following table lists and describes the rules available for attribute constraints within Windchill, and the data types to which they apply.
If multiple constraints are added to an attribute, then the attribute values must satisfy all of the enabled constraints on that attribute.
Rule
Data Types
Description
Example Data
Enumerated Value List
String
Composite
Multi Entry
An enumerated list of legal values. This enumerated list can:
• Use a global enumeration
• Be based on a global enumeration
• Be uniquely created for this condition
If an Enumerated Value List condition uses or is based on a global enumeration, the name of the selected global enumeration displays when creating or editing the constraint.
If there are multiple Enumerated Value List constraints, the common values of the constraints are used to build the legal value list. If there are no common values, the legal value list does not contain values.
You can add Enumerated Value List constraints to multi entry data types that have a FlexPLM Attribute Type of Multi List. If you add Enumerated Value List constraints to multi entry data types that have FlexPLM Attribute Type of Multi Entry, the system ignores the list.
For details on adding data to an enumerated value list, see Enumerated Value List Constraints.
For multiple constraints, if the first list contains Blue, Green, and Red, and the second list contains Blue, Yellow, and Red, the list contains the common values Blue and Red.
Valid Range
Real Number
Date and Time
Integer
The actual value of the attribute must be equal to or between the values specified (the range is inclusive). The From field specifies the minimum value; the To field specifies the maximum value.
If there are multiple constraints, the valid range contains the common values. If there are no common values among the multiple constraints, then there are no valid values for the attribute.
For the numerical data types, if the valid range is specified as From1To7, allowable attribute values include 2 and 7, but not 9.
For multiple integer constraints, if the first constraint has a range from 1 to 6, and the second constraint has a range from 3 to 7, the valid range is from 3 to 6.
For multiple float constraints, if the first constraint has a range from 2.5 to 10.4, the second constraint has a range from 3.5 to 15.6, and the third constraint has a range from 4.2 to 20.6, the valid range is from 4.2 to 10.4.
For multiple string constraints, if the first constraint has a length from 3 to 20 and the second constraint has a range from 10 to 50, the valid range is from 10 to 20.
String Length
String
The length of the string value must be greater than or equal to the minimum, and less than or equal to the maximum values specified (the range is inclusive). The From field specifies the minimum value; the To field specifies the maximum value.
If the string length is specified as From3To200, then the number of characters in the string can be greater than or equal to 3 and less than or equal to 200.
Required
All except Image and Sequence
The attribute must have at least one value.
If there are multiple constraints, the value contains the most restrictive rule.
No data is specified for this constraint.
For multiple constraints, if you have a required enabled and a required disabled constraint, the value is required because of the enabled constraint.
Single-Valued
All data types for local attributes.
No more than one value is allowed.
* 
PTC FlexPLM does not support multi-valued attributes. All attributes in PTC FlexPLM are considered to have this constraint applied.
No data is specified for this constraint.
Legal Type List
Object Reference
Version Reference
The list of allowable types for the reference link.
* 
Only the type and subtypes of the type specified for the Other Side Class attribute can be specified.
* 
You must specify the Internal Name of the type, rather than the Display Name.
PTC FlexPLM types must include the caret ( ^ ) in front of the type name.
If there are multiple constraints, and the constraints are on types in the same branch of the type hierarchy, the value contains the most restrictive rule. If there are multiple constraints, and the constraints are on types in different branches of the type hierarchy, the Legal Type List constraint cannot be created.
If the legal type list is specified as ^com.lcs.wc.document.LCSDocument, then only documents of the Document parent type and all of its subtypes can be selected for this attribute.
For multiple constraints, if the first constraint is specified as ^com.lcs.wc.color.LCSColor and the second constraint is ^com.ptc.SolidColors, the valid Legal Type List is ^com.ptc.SolidColors.
External Enumerated Value List
String
Multi Entry
Composite
An enumerated list of legal values from an external source.
The following list-based attributes are supported:
• Single List
• Multi List
• Color Choice
• Composite
This enumerated list can:
• Support localized values
• Support a sort order
• Be dynamically updated from the external source
* 
Conditions cannot be added on external enumerated value list constraints.
Although the External Enumerated Value List option appears in the Constraints tab, Driven attributes are not supported.
Once the external enumerated value list constraint has been added to an attribute, specify the class name of the EnumerationInfoProvider implementation and the initialization string customized for this value list.
In the first field, enter the fully qualified name of the custom class that is your custom EnumerationInfoProvider.
In the second field, enter the initialization string required by the custom class file.
For details on creating and adding data to the external enumerated value list, see “External Enumerated Value Lists” in the Windchill Help Center.