/// <summary>
/// Overrides the base method to return null if all properties are null for a string format.
/// If the values are not properties then it returns false, so that they would still be added
/// to the list that is passed to the <see cref="ListToString"/> method.
/// </summary>
/// <param name="value">The value to check for null.</param>
/// <param name="format">The value format, for which the null check is performed.</param>
/// <returns>True if the value is considered to be null for the given format, otherwise false.</returns>
public override bool IsValueNull(object value, ValueFormat format)
{
if (format.IsString())
{
List <object> props = value as List <object>;
if (props != null && props.All(p => p is DataProperty))
{
return(props.Cast <DataProperty>().All(p => p.IsNull()));
}
}
return(false);
}
/// <summary>
/// Converts a single value to a given format. For typed formats
/// this method tries to convert various types of values to a nullable DateTime.
/// For string formats it displays the internal DateTime formatted according
/// to the specified <see cref="Format"/>.
/// </summary>
/// <param name="value">A single value to convert to the given format.</param>
/// <param name="format">The value format to convert the value to.</param>
/// <returns>The value converted to the given format.</returns>
protected override object ConvertValue(object value, ValueFormat format)
{
if (format.IsTyped())
{
if (value is DateTime?)
{
return(value);
}
if (value is DateTime)
{
return((DateTime?)value);
}
if (IsValueNull(value, format))
{
return(null);
}
DateTime dt;
if (DateTime.TryParse(Convert.ToString(value), out dt))
{
return(dt);
}
if (format == ValueFormat.Transport)
{
return(null);
}
}
if (format.IsString())
{
DateTime?dt = value as DateTime?;
if (dt == null && value is DateTime)
{
dt = (DateTime)value;
}
if (dt != null && dt.HasValue && !string.IsNullOrEmpty(Format))
{
return(dt.Value.ToString(Format));
}
}
return(base.ConvertValue(value, format));
}
/// <summary>
/// Overrides the base method to return null if all properties are null for a string format.
/// If the values are not properties then it returns false, so that they would still be added
/// to the list that is passed to the <see cref="ListToString"/> method.
/// </summary>
/// <param name="value">The value to check for null.</param>
/// <param name="format">The value format, for which the null check is performed.</param>
/// <returns>True if the value is considered to be null for the given format, otherwise false.</returns>
public override bool IsValueNull(object value, ValueFormat format)
{
if (format.IsString())
{
List<object> props = value as List<object>;
if (props != null && props.All(p => p is DataProperty))
return props.Cast<DataProperty>().All(p => p.IsNull());
}
return false;
}
