private string GenerateOwnershipExpression(string currentUserIdentifier)
{
var sb = new StringBuilder();
if (HasCreatedByField || HasModifiedByField)
{
GetDirectOwnershipExpression(currentUserIdentifier, sb, null);
}
else
{
var related = LinkToOwershipType;
if (related != null && related.Any())
{
var aliases = new FieldEntityAliasDictionary();
sb.AppendLine("EXISTS");
sb.AppendLine("(");
sb.AppendLine("\tSELECT TRUE");
sb.AppendLine($"\tFROM");
GenerateOwnershipJoinExpression(related, sb, aliases);
sb.AppendLine("\tWHERE");
var lastLinkToOwnershipType = related.Last();
var relatedIdentity = lastLinkToOwnershipType.Type.Fields.Where(f => f.IsTrackingUser);
GetRelatedOwnershipExpression(currentUserIdentifier, relatedIdentity, sb, (f) => aliases.GetAliasForLinkingField(lastLinkToOwnershipType));
sb.AppendLine("\tAND");
var linkOnCurrentType = related.First();
sb.AppendLine(
$"\t{aliases.GetAliasForLinkingField(related.Skip(1).Take(1).Single())}.{Util.EscapeSqlReservedWord(linkOnCurrentType.ReferencesTypeField.Name)} = {Util.EscapeSqlReservedWord(linkOnCurrentType.Type.Name)}.{Util.EscapeSqlReservedWord(linkOnCurrentType.Name)}");
sb.AppendLine(")");
}
else
{
sb.AppendLine("TODO"); // unknown relationship type
}
}
return(sb.ToString());
}
protected void GenerateOwnershipJoinExpression(List <Field> related, StringBuilder sb, FieldEntityAliasDictionary aliases)
{
Field previous = null;
string prevAlias = null;
foreach (var field in related)
{
var alias = aliases.CreateAliasForTypeByField(field);
if (previous == null)
{
sb.AppendLine($"\t{field.Type.Name} as {alias}");
}
else
{
sb.AppendLine($"\tINNER JOIN {field.Type.Name} as {alias} on {prevAlias}.{previous.Name} = {alias}.{previous.ReferencesTypeField.Name}");
}
prevAlias = alias;
previous = field;
}
}
protected void GenerateOwnershipJoinExpression(List <Field> related, StringBuilder sb, FieldEntityAliasDictionary aliases)
{
Field previous = null;
string prevAlias = null;
// skip the first item when building the join expression for the security policy because the type we are building the policy for
// will be automatically included as a set of items to filter, and explicitly including it in the policy causes an indefinitely recursive
// security policy to be created (which doesn't work)
foreach (var field in related.Skip(1))
{
var alias = aliases.CreateAliasForTypeByField(field);
if (previous == null)
{
sb.AppendLine($"\t{field.Type.Name} as {alias}");
}
else
{
sb.AppendLine($"\tINNER JOIN {field.Type.Name} as {alias} on {prevAlias}.{previous.Name} = {alias}.{previous.ReferencesTypeField.Name}");
}
prevAlias = alias;
previous = field;
}
}