Display Format Guessing

When no explicit displayFormat is provided on an entity, Squizy automatically generates a reasonable display format based on the entity's ID structure.

How It Works

The DisplayFormatFactory follows this logic:

1. If a @DisplayFormat annotation is present (on the class or via @SquizyEntity(displayFormat = ...)), use it as-is
2. Otherwise, generate a best-effort format based on the entity's ID fields

Best-Effort Rules

• Single simple ID: The display format is ${idFieldName}
• Composite ID (multiple @Id fields): Fields are joined with - separator, e.g., ${field1} - ${field2}
• Embedded ID (@EmbeddedId): The embedded ID's component fields are used, prefixed with the ID field name, e.g., ${id.author} - ${id.title}

Examples

// Generated format: ${id}
@Entity
@SquizyEntity
public class SimpleEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
}

// Explicit format: ${name}
@Entity
@SquizyEntity
@DisplayFormat("${name}")
public class Category {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
}

// Generated format: ${id.isbn} - ${id.author}
@Entity
@SquizyEntity
public class Book {
    @EmbeddedId
    private BookId id;
}

@Embeddable
public class BookId {
    private String isbn;
    private String author;
}

Field-Level Display Format

When an entity field references another entity, you can override how that referenced entity is displayed for that specific field using @DisplayFormat on fields or @SquizyField(displayFormat = ...):

@Entity
@SquizyEntity
public class Address {

    // Show city as "id - name" instead of the City entity's default display format
    @SquizyField(displayFormat = "${id} - ${name}")
    @ManyToOne
    private City city;
}

If no field-level override is present, the referenced entity's own displayFormat is used.

Embedded Fields

For embedded (non-entity) types, the display format resolution checks:

1. @DisplayFormat on the field
2. @DisplayFormat on the embedded class
3. Falls back to empty (no specific display format)