/// <summary>
/// Helper method to recursively walk value roles. A value role
/// is any role that is allowed to have a value constraint.
/// </summary>
/// <param name="playedRoles">Roles from an ObjectType to walk. The assumption is made that the
/// owning ObjectType is either a value type or has a preferred identifier with exactly one role</param>
/// <param name="dataTypeLink">The data type information for the constraint</param>
/// <param name="pathRoots">The <see cref="RolePathObjectTypeRoot"/> relationships from a role path associated
/// with the root path.</param>
/// <param name="previousValueConstraint">The value constraint nearest this value role.
/// Any value constraint on the current set of roles must be a subset of the previousValueConstraint.</param>
/// <param name="skipRole">A role to skip. If the playedRoles came from a preferred identifier,
/// then the skipRole is the opposite role.</param>
/// <param name="walkSubtypes">true to walk subtypes. Should be true if the playedRoles come from an
/// EntityType and false if they come from a ValueType</param>
/// <param name="visitor">The callback delegate</param>
/// <returns>true to continue iteration</returns>
private static bool WalkDescendedValueRoles(IList<Role> playedRoles, IList<RolePathObjectTypeRoot> pathRoots, ValueTypeHasDataType dataTypeLink, ValueConstraint previousValueConstraint, Role skipRole, bool walkSubtypes, ValueRoleVisitor visitor)
{
int count = pathRoots.Count;
for (int i = 0; i < count; ++i)
{
RolePathObjectTypeRoot pathRoot = pathRoots[i];
if (!visitor(null, null, pathRoot, dataTypeLink, pathRoot.ValueConstraint, previousValueConstraint))
{
return false;
}
}
count = playedRoles.Count;
for (int i = 0; i < count; ++i)
{
Role role = playedRoles[i];
SupertypeMetaRole supertypeRole;
if (role == skipRole)
{
// Nothing to do
}
else if (null != (supertypeRole = role as SupertypeMetaRole))
{
if (walkSubtypes)
{
SubtypeFact subtypeFact = (SubtypeFact)role.FactType;
ObjectType subtype;
if (subtypeFact.ProvidesPreferredIdentifier &&
null != (subtype = subtypeFact.Subtype) &&
subtype.PreferredIdentifier == null)
{
if (!WalkDescendedValueRoles(subtype.PlayedRoleCollection, RolePathObjectTypeRoot.GetLinksToRolePathCollection(subtype), dataTypeLink, previousValueConstraint, null, true, visitor))
{
return false;
}
}
}
}
else if (!(role is SubtypeMetaRole))
{
RoleValueConstraint currentValueConstraint = role.ValueConstraint;
if (!visitor(role, null, null, dataTypeLink, currentValueConstraint, previousValueConstraint))
{
return false;
}
if (currentValueConstraint != null && !currentValueConstraint.IsDeleted)
{
previousValueConstraint = currentValueConstraint;
}
foreach (PathedRole pathedRole in PathedRole.GetLinksToRolePathCollection(role))
{
// UNDONE: VALUEROLE This does not correctly report a value constraint from a previous
// path node. Note that this, as well as allowing value restrictions on supertype roles
// (and possibly other patterns), can result in multiple previous value constraints, so
// the callback signature may possibly need to be modified here. As of changeset 1442,
// none of the callbacks use the previousValueConstraint information, so we can ignore
// this for now.
// Note that we visit for the pathed role even if no value constraint is present
// to allow processing for this pathed role.
if (!visitor(role, pathedRole, null, dataTypeLink, pathedRole.ValueConstraint, previousValueConstraint))
{
return false;
}
}
// Walk sequences to find a single-role preferred identifier so
// we can get to the next link.
LinkedElementCollection<ConstraintRoleSequence> sequences = role.ConstraintRoleSequenceCollection;
int sequencesCount = sequences.Count;
for (int j = 0; j < sequencesCount; ++j)
{
UniquenessConstraint constraint = sequences[j] as UniquenessConstraint;
ObjectType identifierFor;
if (null != (constraint = sequences[j] as UniquenessConstraint) &&
null != (identifierFor = constraint.PreferredIdentifierFor) &&
constraint.RoleCollection.Count == 1)
{
RoleBase nextSkipRole = role.OppositeRoleAlwaysResolveProxy;
if (nextSkipRole == null)
{
return false;
}
if (!WalkDescendedValueRoles(identifierFor.PlayedRoleCollection, RolePathObjectTypeRoot.GetLinksToRolePathCollection(identifierFor), dataTypeLink, previousValueConstraint, nextSkipRole.Role, true, visitor))
{
return false;
}
}
}
}
}
return true;
}
/// <summary>
/// Get all value roles including all roles directly attached to the provided
/// object type and any roles descended from this one through prefererred identifiers.
/// Walks the opposite direction of <see cref="Role.GetValueRoles()"/>
/// </summary>
/// <param name="anchorType">The <see cref="ObjectType"/> to walk descended roles for</param>
/// <param name="unattachedRole">A role to test that is not currently attached to the anchorType.
/// If unattachedRole is not null, then only this role will be tested. Otherwise, all current played
/// roles will be walked.</param>
/// <param name="unattachedPreferredIdentifier">A preferred identifier to test that is not currently
/// attached to the anchorType.</param>
/// <param name="visitor">A <see cref="ValueRoleVisitor"/> callback delegate.</param>
public static void WalkDescendedValueRoles(ObjectType anchorType, Role unattachedRole, UniquenessConstraint unattachedPreferredIdentifier, ValueRoleVisitor visitor)
{
ValueTypeHasDataType dataTypeLink = anchorType.GetDataTypeLink();
if (null == unattachedPreferredIdentifier &&
null != (dataTypeLink = anchorType.GetDataTypeLink()))
{
ObjectType unattachedRolePlayer;
WalkDescendedValueRoles(
(unattachedRole != null) ? new Role[] { unattachedRole } as IList<Role> : anchorType.PlayedRoleCollection,
RolePathObjectTypeRoot.GetLinksToRolePathCollection(anchorType),
dataTypeLink,
anchorType.ValueConstraint,
null,
(null == unattachedRole || null == (unattachedRolePlayer = unattachedRole.RolePlayer)) ? false : !unattachedRolePlayer.IsValueType,
visitor);
}
else
{
LinkedElementCollection<Role> roles;
UniquenessConstraint preferredIdentifier;
if (null != (preferredIdentifier = unattachedPreferredIdentifier ?? anchorType.ResolvedPreferredIdentifier) &&
(roles = preferredIdentifier.RoleCollection).Count == 1)
{
Role currentRole = roles[0];
Role[] valueRoles = currentRole.GetValueRoles();
if (valueRoles != null)
{
ValueConstraint nearestValueConstraint = null;
int valueRolesCount = valueRoles.Length;
for (int i = valueRolesCount - 1; i >= 0; --i)
{
nearestValueConstraint = valueRoles[i].ValueConstraint;
if (nearestValueConstraint != null)
{
break;
}
}
ObjectType valueType = valueRoles[0].RolePlayer;
dataTypeLink = valueType.GetDataTypeLink();
if (nearestValueConstraint == null)
{
nearestValueConstraint = valueType.ValueConstraint;
}
RoleBase nextSkipRole = currentRole.OppositeRoleAlwaysResolveProxy;
if (nextSkipRole != null)
{
WalkDescendedValueRoles(
(unattachedRole != null) ? new Role[] { unattachedRole } as IList<Role> : anchorType.PlayedRoleCollection,
RolePathObjectTypeRoot.GetLinksToRolePathCollection(anchorType),
dataTypeLink,
nearestValueConstraint,
nextSkipRole.Role,
true,
visitor);
}
}
}
}
}