You can specify what values are allowed for your custom Tag value types. Allowed tag values are defined in the TTAGALLOWEDVALUE table.

For example, you want to create a marital status tag to store each customer's marital status. The possible values would be single, married, divorced, widowed, or common law. You could use the out-of-the-box text tag value type, but that would allow CM users to enter invalid values when creating conditions with this tag. A better way would be to define a marital status tag value type that would only allow users to enter specific values. The following SQL creates the tag value type.

insert into TTAGVALUETYPE(uidpk, guid, java_type) values(17, 'maritalStatus', 'java.lang.String');

The following SQL defines the operators that are available to users when creating condition statements with tags of this type.

insert into TTAGVALUETYPEOPERATOR(tagvaluetype_guid, tagoperator_guid)
	values('maritalStatus', 'equalTo'), ('maritalStatus', 'notEqualTo');

The following SQL sets the values that are allowed for the tag value type.

insert into TTAGALLOWEDVALUE(uidpk, value, tagvaluetype_guid, description, ordering)
	values(42, 'single', 'maritalStatus', 'Single', 1),
	(43, 'married', 'maritalStatus', 'Married', 2),
	(44, 'divorced', 'maritalStatus', 'Divorced', 3),
	(45, 'widowed', 'maritalStatus', 'Widowed', 4),
	(46, 'common law', 'maritalStatus', 'Common law', 5);

In the CM's serviceCM.xml file, find the selectableTagValueServiceLocator bean definiton and add the following value provider:

<entry><key><value>maritalStatus</value></key>
        <bean class="com.elasticpath.tags.service.impl.InternalSelectableStringTagValueProviderImpl"></bean>
</entry>

When a user creates a condition statement with this tag, the condition builder UI displays a drop-down list containing only the allowed values.

You can specify what operators are supported by Tag value types. The following tag operators are provided out of the box:

The following SQL associates a tag operator with a tag value type.

insert into TTAGVALUETYPEOPERATOR(tagvaluetype_guid, tagoperator_guid)
     values('phone_number', 'includes'),
          ('phone_number', 'greaterThan'),
         ('phone_number', 'lessThan'),
          ('phone_number', 'notIncludes');

You can specify validation constraints on Tag value types to prevent users from setting invalid tag values. Validation constraints are stored as strings in the TVALIDATIONCONSTRAINTS table. They are expressed in the Spring Expression Language format (also called SpEL), which provides a rich yet easy to learn syntax for defining validation rules.

For example, you want to create a tag to store North American telephone numbers (XXX-XXX-XXXX). The following SQL creates the tag value type and its supported operators.

insert into TTAGVALUETYPE(uidpk, guid, java_type)
     values(17, 'phone_number', 'java.lang.String');

insert into TTAGVALUETYPEOPERATOR(tagvaluetype_guid, tagoperator_guid)
     values('phone_number', 'includes'),
          ('phone_number', 'greaterThan'),
         ('phone_number', 'lessThan'),
          ('phone_number', 'notIncludes');

The following SQL creats the validation constraint that will be used to determine whether the user input is valid.

insert into TVALIDATIONCONSTRAINTS(uidpk, object_uid, error_message_key, validation_constraint, type)
    values(17, 17, 'validationTagPhoneNumberError',
    '(#isValidConditionType((#this))) == true AND tagValue.matches(\'[2-9]\\\\d{2}-\\\\d{3}-\\\\d{4}\')',
    'TagValueType');

The validation_constraint column contains the SpEL code that is used to evaluate the user input. In this case, it tests the user input against a regular expression.