Fields

Fields are fundamental components that define the structure and behavior of data within domain models such as Aggregates, Entities, and Value Objects. This section provides a comprehensive guide to the various types of fields available in Protean, detailing their attributes, options, and built-in functionalities that help in the effective management of domain data.

Fields in Protean are designed to encapsulate data properties in domain models, ensuring data integrity and aligning with the business domain's rules and logic. They play a critical role in defining the schema of data containers and are pivotal in enforcing validation, defaults, associations, and more.

Internally, fields are python descriptors that manage the attributes of elements. They help Protean fine-tune and customize attribute access, making it possible to define properties, manage attributes, and control data validation.

Field Arguments

Protean fields come with various options to model real-world scenarios effectively. These include required, default, choices, and unique, among others, which allow for a highly customizable and robust domain model definition.

Read more in Arguments section.

Types of Fields

Simple Fields

Simple fields handle basic data types like strings, integers, and dates. They are the building blocks for defining straightforward data attributes in models. Options like max_length for String or max_value and min_value for numeric fields like Integer and Float allow you to specify constraints directly in the model's definition.

Container Fields

Container fields are used for data types that hold multiple values, such as lists and dictionaries. These fields support complex structures and provide options such as content_type for List fields to ensure type consistency within the collection. Protean optimizes storage and retrieval operations for these fields by leveraging database-specific features when available.

Association Fields

Association fields define relationships between different domain models, such as one-to-one, one-to-many, and many-to-many associations. These fields help in mapping complex domain relationships and include functionalities to manage related objects efficiently, preserving data integrity across the domain.