public static InternalSchemaDefinition Create(Type userType, SchemaDefinition userSchemaDefinition)
{
Contracts.AssertValue(userType);
Contracts.AssertValueOrNull(userSchemaDefinition);
if (userSchemaDefinition == null)
{
userSchemaDefinition = SchemaDefinition.Create(userType);
}
Column[] dstCols = new Column[userSchemaDefinition.Count];
for (int i = 0; i < userSchemaDefinition.Count; ++i)
{
var col = userSchemaDefinition[i];
if (col.MemberName == null)
{
throw Contracts.ExceptParam(nameof(userSchemaDefinition), "Null field name detected in schema definition");
}
bool isVector;
DataKind kind;
MemberInfo memberInfo = null;
if (!col.IsComputed)
{
memberInfo = userType.GetField(col.MemberName);
if (memberInfo == null)
{
memberInfo = userType.GetProperty(col.MemberName);
}
if (memberInfo == null)
{
throw Contracts.ExceptParam(nameof(userSchemaDefinition), "No field or property with name '{0}' found in type '{1}'",
col.MemberName,
userType.FullName);
}
//Clause to handle the field that may be used to expose the cursor channel.
//This field does not need a column.
if ((memberInfo is FieldInfo && (memberInfo as FieldInfo).FieldType == typeof(IChannel)) ||
(memberInfo is PropertyInfo && (memberInfo as PropertyInfo).PropertyType == typeof(IChannel)))
{
continue;
}
GetVectorAndKind(memberInfo, out isVector, out kind);
}
else
{
var parameterType = col.ReturnType;
if (parameterType == null)
{
throw Contracts.ExceptParam(nameof(userSchemaDefinition), "No return parameter found in computed column.");
}
GetVectorAndKind(parameterType, "returnType", out isVector, out kind);
}
// Infer the column name.
var colName = string.IsNullOrEmpty(col.ColumnName) ? col.MemberName : col.ColumnName;
// REVIEW: Because order is defined, we allow duplicate column names, since producing an IDataView
// with duplicate column names is completely legal. Possible objection is that we should make it less
// convenient to produce "hidden" columns, since this may not be of practical use to users.
ColumnType colType;
if (col.ColumnType == null)
{
// Infer a type as best we can.
PrimitiveType itemType = PrimitiveType.FromKind(kind);
colType = isVector ? new VectorType(itemType) : (ColumnType)itemType;
}
else
{
// Make sure that the types are compatible with the declared type, including
// whether it is a vector type.
VectorType columnVectorType = col.ColumnType as VectorType;
if (isVector != (columnVectorType != null))
{
throw Contracts.ExceptParam(nameof(userSchemaDefinition), "Column '{0}' is supposed to be {1}, but type of associated field '{2}' is {3}",
colName, columnVectorType != null ? "vector" : "scalar", col.MemberName, isVector ? "vector" : "scalar");
}
ColumnType itemType = columnVectorType?.ItemType ?? col.ColumnType;
if (kind != itemType.RawKind)
{
throw Contracts.ExceptParam(nameof(userSchemaDefinition), "Column '{0}' is supposed to have item kind {1}, but associated field has kind {2}",
colName, itemType.RawKind, kind);
}
colType = col.ColumnType;
}
dstCols[i] = col.IsComputed ?
new Column(colName, colType, col.Generator, col.Metadata)
: new Column(colName, colType, memberInfo, col.Metadata);
}
return(new InternalSchemaDefinition(dstCols));
}
public static InternalSchemaDefinition Create(Type userType, SchemaDefinition.Direction direction)
{
var userSchemaDefinition = SchemaDefinition.Create(userType, direction);
return(Create(userType, userSchemaDefinition));
}