private static ColumnInfo TryGetColumnInfo(
[NotNull] IList <string> aliases,
[NotNull] IList <ColumnInfoFactory> factories,
[NotNull] string expressionToken,
out int tableAliasIndex)
{
int tableSeparatorIndex = expressionToken.IndexOf(_tableSeparator, 0);
tableAliasIndex = -1;
if (tableSeparatorIndex < 0)
{
// there is no separator in the token --> ignore
return(null);
}
string tableNameOrAlias = expressionToken.Substring(0, tableSeparatorIndex);
int aliasIndex = aliases.IndexOf(tableNameOrAlias);
if (aliasIndex < 0)
{
return(null);
}
// the qualified field name references one of the aliases ("L.FIELD1")
string tokenWithoutQualifier =
expressionToken.Substring(tableSeparatorIndex + 1);
ColumnInfoFactory factory = factories[aliasIndex];
ColumnInfo columnInfo = factory.GetColumnInfo(tokenWithoutQualifier);
if (columnInfo == null)
{
return(null);
}
tableAliasIndex = aliasIndex;
return(columnInfo);
}
public static TableView Create([NotNull] ITable table,
[CanBeNull] string expression,
bool useAsConstraint,
bool caseSensitive = false)
{
Assert.ArgumentNotNull(table, nameof(table));
if (expression == null || expression.Trim().Length == 0)
{
// this filter helper won't do much
return(new TableView(new ColumnInfo[] { }, null));
}
// read/remove case sensitivity override from expression
bool?caseSensitivityOverride;
expression = ExpressionUtils.ParseCaseSensitivityHint(expression,
out caseSensitivityOverride);
if (caseSensitivityOverride != null)
{
caseSensitive = caseSensitivityOverride.Value;
}
var columnInfos = new List <ColumnInfo>();
var addedFields = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
IFields fields = table.Fields;
if (table.HasOID)
{
string oidFieldName = table.OIDFieldName.ToUpper();
int fieldIndex = table.FindField(oidFieldName);
IField field = fields.Field[fieldIndex];
columnInfos.Add(new FieldColumnInfo(table, field, fieldIndex));
addedFields.Add(oidFieldName);
}
var factory = new ColumnInfoFactory(table);
foreach (string token in ExpressionUtils.GetExpressionTokens(expression))
{
if (addedFields.Contains(token))
{
continue;
}
ColumnInfo columnInfo = factory.GetColumnInfo(token);
if (columnInfo != null)
{
columnInfos.Add(columnInfo);
addedFields.Add(token);
}
}
var dataTable = new DataTable(DatasetUtils.GetName(table))
{
CaseSensitive = caseSensitive
};
foreach (ColumnInfo columnInfo in columnInfos)
{
dataTable.Columns.Add(columnInfo.ColumnName, columnInfo.ColumnType);
}
var dataView = new DataView(dataTable);
if (useAsConstraint)
{
dataView.RowFilter = expression;
}
return(new TableView(columnInfos, dataView));
}