void IEnumerator.Reset()
{
xml?.Dispose();
xml = null;
columns = null;
currentRow = null;
state = ReadingState.Unread;
} // proc Reset
} // proc Dispose
#endregion
#region -- IEnumerator ------------------------------------------------------------
private bool MoveNext(bool headerOnly)
{
switch (state)
{
#region -- ReadingState.Unread --
case ReadingState.Unread:
// open the xml stream
xml = owner.request.GetXmlStreamAsync(owner.path, owner.acceptedMimeType).Result;
xml.Read();
if (xml.NodeType == XmlNodeType.XmlDeclaration)
{
xml.Read();
}
if (xml.NodeType != XmlNodeType.Element || xml.LocalName != xnView.LocalName)
{
throw new InvalidDataException($"Expected \"{xnView}\", read \"{xml.LocalName}\".");
}
xml.Read();
if (xml.NodeType != XmlNodeType.Element || xml.LocalName != xnFields.LocalName)
{
throw new InvalidDataException($"Expected \"{xnFields}\", read \"{xml.LocalName}\".");
}
var viewColumns = new List <ViewDataColumn>();
var fields = (XElement)XNode.ReadFrom(xml);
foreach (var field in fields.Elements())
{
var columnName = field.Name.LocalName;
var columnDataType = LuaType.GetType(field.GetAttribute("type", "string"), lateAllowed: false).Type;
var columnId = field.GetAttribute("field", String.Empty);
var attributes = new PropertyDictionary();
// add colum id
if (!String.IsNullOrEmpty(columnId))
{
attributes.SetProperty("field", typeof(string), columnId);
}
foreach (var c in field.Elements("attribute"))
{
if (c.IsEmpty)
{
continue;
}
var attributeName = c.GetAttribute("name", String.Empty);
if (String.IsNullOrEmpty(attributeName))
{
continue;
}
attributes.SetProperty(attributeName, LuaType.GetType(c.GetAttribute("type", "string"), lateAllowed: false).Type, c.Value);
} // foreach c
viewColumns.Add(new ViewDataColumn(columnName, columnDataType, attributes));
} // foreach field
if (viewColumns.Count < 1)
{
throw new InvalidDataException("No header found.");
}
columns = viewColumns.ToArray();
state = ReadingState.FetchFirstRow;
if (headerOnly)
{
return(true);
}
else
{
goto case ReadingState.FetchFirstRow;
}
#endregion
#region -- ReadingState.FetchFirstRow --
case ReadingState.FetchFirstRow:
if (xml.NodeType != XmlNodeType.Element || xml.LocalName != xnRows.LocalName)
{
throw new InvalidDataException($"Expected \"{xnRows}\", read \"{xml.LocalName}\".");
}
if (xml.IsEmptyElement)
{
xml.Read();
if (xml.NodeType != XmlNodeType.EndElement || xml.LocalName != xnView.LocalName)
{
throw new InvalidDataException($"Expected \"{xnView}\", read \"{xml.LocalName}\".");
}
xml.Read();
if (!xml.EOF)
{
throw new InvalidDataException("Unexpected eof.");
}
state = ReadingState.Complete;
goto case ReadingState.Complete;
} // if xml.IsEmptyElement
else
{
xml.Read();
state = ReadingState.FetchRows;
goto case ReadingState.FetchRows;
}
#endregion
#region -- ReadingState.FetchRows --
case ReadingState.FetchRows:
if (xml.NodeType != XmlNodeType.Element || xml.LocalName != xnRow.LocalName)
{
throw new InvalidDataException($"Expected \"r\", read \"{xml.LocalName}\".");
}
var values = new object[columns.Length];
if (!xml.IsEmptyElement)
{
var rowData = (XElement)XNode.ReadFrom(xml);
foreach (var column in rowData.Elements())
{
var columnIndex = Array.FindIndex(columns, c => String.Compare(c.Name, column.Name.LocalName, StringComparison.OrdinalIgnoreCase) == 0);
if (columnIndex != -1)
{
values[columnIndex] = Procs.ChangeType(column.Value, columns[columnIndex].DataType);
}
}
} // if xml.IsEmptyElement
else
{
// Without a call to XNode.ReadFrom() it's necessary to read to the next node.
xml.Read();
}
currentRow = new ViewDataRow(this, values);
if (xml.NodeType == XmlNodeType.Element && xml.LocalName == xnRow.LocalName)
{
return(true);
}
if (xml.NodeType != XmlNodeType.EndElement || xml.LocalName != xnRows.LocalName)
{
throw new InvalidDataException($"Expected \"{xnRows}\", read \"{xml.LocalName}\".");
}
xml.Read();
if (xml.NodeType != XmlNodeType.EndElement || xml.LocalName != xnView.LocalName)
{
throw new InvalidDataException($"Expected \"{xnView}\", read \"{xml.LocalName}\".");
}
xml.Read();
if (!xml.EOF)
{
throw new InvalidDataException("Unexpected eof.");
}
state = ReadingState.Complete;
return(true);
#endregion
case ReadingState.Complete:
return(false);
default:
throw new InvalidOperationException("The state of the object is invalid.");
} // switch state
} // func MoveNext