Do Azure table services entities have an equivalent of NonSerializedAttribute?

Question

If I'm trying to serialize a normal CLR object, and I do not want a particular member variable to be serialized, I can tag it with the

[NonSerialized]

attribute. If I am creating a table services entity, is there an equivalent attribute I can use to tell Azure table services to ignore this property?

Answer 1

For Version 2.1 there is a new Microsoft.WindowsAzure.Storage.Table.IgnoreProperty attribute. See the 2.1 release notes for more information: http://blogs.msdn.com/b/windowsazurestorage/archive/2013/09/07/announcing-storage-client-library-2-1-rtm.aspx.

Answer 2

There's no equivalent I know of.

This post says how you can achieve the desired effect - http://blogs.msdn.com/b/phaniraj/archive/2008/12/11/customizing-serialization-of-entities-in-the-ado-net-data-services-client-library.aspx

Alternatively, if you can get away with using "internal" rather than "public" on your property then it will not get persisted with the current SDK (but this might change in the future).

Answer 3

For version 2.0 of the Table Storage SDK there is a new way to achieve this.

You can now override the WriteEntity method on TableEntity and remove any entity properties that have an attribute on them. I derive from a class that does this for all my entities, like:

public class CustomSerializationTableEntity : TableEntity
{
    public CustomSerializationTableEntity()
    {
    }

    public CustomSerializationTableEntity(string partitionKey, string rowKey)
        : base(partitionKey, rowKey)
    {
    }

    public override IDictionary<string, EntityProperty> WriteEntity(Microsoft.WindowsAzure.Storage.OperationContext operationContext)
    {
        var entityProperties = base.WriteEntity(operationContext);

        var objectProperties = this.GetType().GetProperties();

        foreach (PropertyInfo property in objectProperties)
        {
            // see if the property has the attribute to not serialization, and if it does remove it from the entities to send to write
            object[] notSerializedAttributes = property.GetCustomAttributes(typeof(NotSerializedAttribute), false);
            if (notSerializedAttributes.Length > 0)
            {
                entityProperties.Remove(property.Name);
            }
        }

        return entityProperties;
    }
}

[AttributeUsage(AttributeTargets.Property)]
public class NotSerializedAttribute : Attribute
{
}

Then you can make use of this class for your entities like

public class MyEntity : CustomSerializationTableEntity
{
     public MyEntity()
     {
     }

     public string MySerializedProperty { get; set; }

     [NotSerialized]
     public List<string> MyNotSerializedProperty { get; set; }
}