Field Configuration¶

Field configuration is handled through [DynamoField] attributes on the mapper class. These attributes target model properties and allow you to override defaults without touching your domain models.

Basic Usage¶

using DynamoMapper.Runtime;

[DynamoMapper]
[DynamoField(nameof(Product.Name), AttributeName = "productName", Required = true)]
[DynamoField(nameof(Product.Description), OmitIfNull = true, OmitIfEmptyString = true)]
public static partial class ProductMapper
{
    public static partial Dictionary<string, AttributeValue> ToItem(Product source);
    public static partial Product FromItem(Dictionary<string, AttributeValue> item);
}

Nested Property Overrides (Dot Notation)¶

Use dot notation to override nested properties without adding attributes to nested types:

[DynamoMapper]
[DynamoField("ShippingAddress.Line1", AttributeName = "addr_line1")]
[DynamoField("ShippingAddress.City", AttributeName = "addr_city")]
public static partial class OrderMapper
{
    public static partial Dictionary<string, AttributeValue> ToItem(Order source);
    public static partial Order FromItem(Dictionary<string, AttributeValue> item);
}

Notes: - Dot-notation overrides force inline mapping for the nested path. - Invalid paths emit DM0008.

Supported Options¶

Option	Description
`AttributeName`	Overrides the DynamoDB attribute name.
`Required`	Controls requiredness during `FromItem`.
`Kind`	Forces a specific `DynamoKind`.
`OmitIfNull`	Omits null values during `ToItem`.
`OmitIfEmptyString`	Omits empty strings during `ToItem`.
`ToMethod`	Uses a custom method to serialize a value.
`FromMethod`	Uses a custom method to deserialize a value.
`Format`	Overrides default format for date/time/enum conversions.