Migrating to v15.0.0

CsvHelper 15 makes [Ignore] work on a reference member: a member whose type is a class that auto mapping maps as its own set of columns, such as an Address property with Street and City. The attribute now ignores all of that class's columns. In 14 it had no effect there. No API was removed or renamed.

Ignoring a reference member

In 14, leaving a reference's columns out took an [Ignore] on each member of the referenced class, which left them out wherever that class was used. Now one attribute on the reference member does it:

public class Person
{
    public int Id { get; set; }
    public Address Address { get; set; }
}

public class Address
{
    [Ignore]
    public string Street { get; set; }

    [Ignore]
    public string City { get; set; }
}

public class Person
{
    public int Id { get; set; }

    [Ignore]
    public Address Address { get; set; }
}

public class Address
{
    public string Street { get; set; }
    public string City { get; set; }
}

Either way, writing a Person writes the header Id, and reading one doesn't read Street or City.

• An [Ignore] you already have starts working. If a reference member has the attribute, its columns are no longer read or written. Remove the attribute to keep them.
• Nested references: 15.0.0 ignores the members of the referenced class, but not the references inside it. 15.0.10 ignores the whole tree.