public static IEnumerable <Column> GetColumnsForType <T>() where T : PersistenceModel
{
return(DbHelper.GetColumnsForType(typeof(T)));
}
/// <summary>
/// Retrieve a collection of columns for the given type
/// </summary>
/// <param name="entityType">The type to inspect (it is expected to be of type PersistenceModel)</param>
/// <returns></returns>
public static IEnumerable <Column> GetColumnsForType(Type entityType)
{
if (!typeof(PersistenceModel).IsAssignableFrom(entityType))
{
throw new ArgumentException("Invalid type specified, expecting a type of PersistenceModel", "entityType");
}
var columns = new Collection <Column>();
// Sort the properties so the id property is listed first
var properties = entityType.GetProperties()
.OrderBy(p => p.Name, Comparer <string> .Create((x, y) =>
{
// Ensure id is at the front of the list
if (x.ToLowerInvariant() == "id")
{
return(-1);
}
if (y.ToLowerInvariant() == "id")
{
return(1);
}
return(x.CompareTo(y));
}));
foreach (var member in properties)
{
// Map properties to fields
if (member.Name.ToLowerInvariant() == "id")
{
columns.Add(new Column()
{
Name = "_Id", // This is the name of the backing variable of the id in the PersistenceModel
Type = ColumnType.TEXT,
IsPrimaryKey = true,
IsForeignKey = false,
PropertyPath = "Id"
});
}
else
{
// Detect the type of the property down to one of TEXT, NUMERIC, INTEGER, REAL
var fieldType = ColumnType.UNKNOWN;
var typeCode = Type.GetTypeCode(member.GetUnderlyingType());
var foreignKey = false;
var propertyPath = member.Name;
var name = member.Name;
switch (typeCode)
{
case TypeCode.Byte:
case TypeCode.Int16:
case TypeCode.Int32:
case TypeCode.Int64:
case TypeCode.SByte:
case TypeCode.UInt16:
case TypeCode.UInt32:
case TypeCode.UInt64:
fieldType = ColumnType.INTEGER;
break;
case TypeCode.Char:
case TypeCode.String:
fieldType = ColumnType.TEXT;
break;
case TypeCode.Double:
case TypeCode.Single:
fieldType = ColumnType.REAL;
break;
case TypeCode.Boolean:
case TypeCode.DateTime:
case TypeCode.Decimal:
fieldType = ColumnType.NUMERIC;
break;
case TypeCode.Object:
// We will store the id of the related entity in this field (Guid format)
// but only if this is not the aggregate root child entity and not the aggregate root object
if (typeof(PersistenceModel).IsAssignableFrom(member.GetUnderlyingType()) &&
DbHelper.IsOwner(member))
{
fieldType = ColumnType.TEXT;
foreignKey = true;
name = member.Name + "Id";
propertyPath = member.Name + ".Id";
}
break;
}
if (fieldType != ColumnType.UNKNOWN)
{
columns.Add(new Column()
{
Name = name,
Type = fieldType,
IsPrimaryKey = false,
IsForeignKey = foreignKey,
PropertyPath = propertyPath
});
}
}
}
return(columns);
}