/// <summary>
/// Generic extension method yielding objects of specified type from table.
/// </summary>
/// <remarks>
/// Exceptions are not catched. It works on all or nothing basis.
/// Only primitives and enums are supported as property.
/// Currently supports only tables with header.
/// </remarks>
/// <typeparam name="T">Type to map to. Type should be a class and should have parameterless constructor.</typeparam>
/// <param name="table">Table object to fetch</param>
/// <param name="onCaught"></param>
/// <param name="configurationAction"></param>
/// <returns>An enumerable of the generating type</returns>
public static IEnumerable <T> AsEnumerable <T>(this ExcelTable table, OnCaught <T> onCaught = null, Action <IExcelConfiguration <T> > configurationAction = null) where T : class, new()
{
IExcelConfiguration <T> configuration = DefaultExcelConfiguration <T> .Instance;
configurationAction?.Invoke(configuration);
List <KeyValuePair <int, PropertyInfo> > mapping = PrepareMappings <T>(table);
ExcelAddress bounds = table.GetDataBounds();
// Parse table
for (int row = bounds.Start.Row; row <= bounds.End.Row; row++)
{
var item = (T)Activator.CreateInstance(typeof(T));
foreach (KeyValuePair <int, PropertyInfo> map in mapping)
{
object cell = table.WorkSheet.Cells[row, map.Key + table.Address.Start.Column].Value;
PropertyInfo property = map.Value;
try
{
TrySetProperty(item, property, cell);
}
catch (Exception ex)
{
if (!configuration.SkipCastingErrors)
{
var exceptionArgs = new ExcelTableExceptionArgs
{
ColumnName = table.Columns[map.Key].Name,
ExpectedType = property.PropertyType,
PropertyName = property.Name,
CellValue = cell,
CellAddress = new ExcelCellAddress(row, map.Key + table.Address.Start.Column)
};
throw new ExcelTableConvertException($"The expected type of '{exceptionArgs.PropertyName}' property is '{exceptionArgs.ExpectedType.Name}', but the cell [{exceptionArgs.CellAddress.Address}] contains an invalid value.",
ex, exceptionArgs
);
}
}
}
onCaught?.Invoke(item, row);
// TODO:
if (!configuration.SkipValidationErrors)
{
// Validate parsed object according to data annotations
item.Validate(row);
}
yield return(item);
}
}
/// <inheritdoc />
/// <summary>
/// Custom constructor that takes message, inner exception and conversion arguments
/// </summary>
/// <param name="message">Exception message</param>
/// <param name="inner">Actual conversion exception catched</param>
/// <param name="args">Information related to the circumstances of the exception</param>
public ExcelTableConvertException(string message, Exception inner, ExcelTableExceptionArgs args)
: base(message, inner)
{
Args = args;
}