private IntegerVariable getOrCreateVariable(Attribute attribute) {
String attributeName = attribute.getName();
String featureId = attribute.getFeature().getId();
String identifier = attributeValue;
String[] parts = new String[] {identifier, featureId, attributeName};
String attributeId = concatenate(parts, attributeDelimiter);
IntegerVariable integerVariable = nodeVariables.get(attributeId);
if (integerVariable == null) {
integerVariable = createAttributeValueVariable(attribute, attributeId);
nodeVariables.put(attributeId, integerVariable);
}
return integerVariable;
}
private void transformAttribute(Attribute attribute) {
// 0: attribute is disabled if feature is disabled
// 1: attribute is enabled if feature is selected
IntegerVariable featureVariable = getOrCreateVariable(attribute.getFeature());
Constraint memberConstraint = getMemberConstraint(attribute);
// if feature is enabled, then attribute value must be in bounds
Constraint featureEnabled = Choco.eq(featureVariable, 1);
Constraint checkAttribute = Choco.implies(featureEnabled, memberConstraint);
getModel().addConstraint(checkAttribute);
IntegerVariable attributeVariable = getOrCreateVariable(attribute);
Constraint featureDisabled = Choco.eq(featureVariable, 0);
Constraint attrDisabled = Choco.eq(attributeVariable, attributeDisabled);
Constraint disabledAttr = Choco.ifOnlyIf(featureDisabled, attrDisabled);
getModel().addConstraint(disabledAttr);
}