Class PropertyMetadata

Represents cached reflection metadata for a single serializable property or field belonging to a type managed by the Scylla serialization system.

Inheritance
object
PropertyMetadata
Inherited Members
Namespace: Scylla.Core.Util.Serialization
Assembly: ScyllaCore.dll
Syntax
public sealed class PropertyMetadata
Remarks

PropertyMetadata is constructed once per member during type discovery (performed by TypeMetadata) and stored in a TypeMetadataCache for reuse across all subsequent serialization operations. This design eliminates the per-call overhead of repeated reflection lookups and attribute scanning.

Getter and setter access is provided through compiled delegates rather than raw MemberInfo reflection calls, which reduces invocation cost at the expense of a one-time delegate creation cost during construction.

Instances of this class are immutable and thread-safe after construction. They may be safely shared across multiple concurrent serialization contexts.

A member is included in serialization if it is public, or if it carries the ScyllaIncludeAttribute. A member can be explicitly excluded with ScyllaIgnoreAttribute. Custom serialized names, ordering, and required-field enforcement are controlled via ScyllaPropertyAttribute.

Constructors

PropertyMetadata(FieldInfo, ScyllaPropertyAttribute)

Initializes a new PropertyMetadata instance that describes a C# field member.

Declaration
public PropertyMetadata(FieldInfo field, ScyllaPropertyAttribute attribute)
Parameters
Type Name Description
FieldInfo field

The FieldInfo for the field to describe. Must not be null. Compiler-generated backing fields (those whose names contain < or >) should be filtered out before construction.
ScyllaPropertyAttribute attribute

The optional ScyllaPropertyAttribute decorating the field, or null if the field carries no such attribute. When null, default values are used for Name, Order, and IsRequired.
Exceptions
Type Condition
ArgumentNullException

Thrown if field is null.

PropertyMetadata(PropertyInfo, ScyllaPropertyAttribute)

Initializes a new PropertyMetadata instance that describes a C# property member.

Declaration
public PropertyMetadata(PropertyInfo property, ScyllaPropertyAttribute attribute)
Parameters
Type Name Description
PropertyInfo property

The PropertyInfo for the property to describe. Must not be null. Indexer properties (those with index parameters) are not supported and should be filtered out before construction.
ScyllaPropertyAttribute attribute

The optional ScyllaPropertyAttribute decorating the property, or null if the property carries no such attribute. When null, default values are used for Name, Order, and IsRequired.
Exceptions
Type Condition
ArgumentNullException

Thrown if property is null.

Properties

CanRead

Gets whether the underlying member supports reading its value.

Declaration
public bool CanRead { get; }
Property Value
Type Description
bool

For a property, true if the property has a getter (including non-public getters); for a field, always true because all fields are readable. When false, calling GetValue(object) will throw InvalidOperationException.
See Also

CanWrite

Gets whether the underlying member supports writing a value to it.

Declaration
public bool CanWrite { get; }
Property Value
Type Description
bool

For a property, true if the property has a setter (including non-public setters); for a field, true unless the field is declared readonly (i.e., IsInitOnly is false). When false, calling SetValue(object, object) will throw InvalidOperationException.
See Also

DefaultValue

Gets the language-default value for this member's Type.

Declaration
public object DefaultValue { get; }
Property Value
Type Description
object

For value types, the result of CreateInstance(Type) (e.g., 0 for int, false for bool, a zeroed struct for custom structs). For reference types, null. Used by IsDefaultValue(object) and by the serialization engine when DefaultValueHandling is set to Ignore.
See Also

IsRequired

Gets whether this property or field must be present in the serialized data during deserialization.

Declaration
public bool IsRequired { get; }
Property Value
Type Description
bool

true if the member is decorated with ScyllaPropertyAttribute and Required is set to true; otherwise, false. When true, the deserializer will throw a SerializationException if the key is absent from the input data.
See Also

MemberInfo

Gets the underlying reflection descriptor for this member.

Declaration
public MemberInfo MemberInfo { get; }
Property Value
Type Description
MemberInfo

Either a PropertyInfo or a FieldInfo instance, depending on which constructor overload was used to create this PropertyMetadata. Callers can cast to the concrete type when property-specific or field-specific reflection behavior is needed.

MemberName

Gets the original name of the property or field as declared in the source type, independent of any custom serialized name specified via ScyllaPropertyAttribute.

Declaration
public string MemberName { get; }
Property Value
Type Description
string

The C# identifier name of the underlying PropertyInfo or FieldInfo member.
See Also

Name

Gets the serialized name of the property or field as it appears in the output document (e.g., the JSON key).

Declaration
public string Name { get; }
Property Value
Type Description
string

The value of Name if the member is decorated with ScyllaPropertyAttribute and a custom name was specified; otherwise, the original member name as declared in the type (i.e., the same value as MemberName).
See Also

Order

Gets the relative serialization order for this property or field. Members with lower order values are serialized before members with higher values.

Declaration
public int Order { get; }
Property Value
Type Description
int

The value of Order if the member is decorated with ScyllaPropertyAttribute and an order was specified; otherwise, MaxValue, which places this member after all explicitly ordered members. Members sharing the same order value are sorted alphabetically by Name.
See Also

Type

Gets the runtime Type of the value stored in this property or field.

Declaration
public Type Type { get; }
Property Value
Type Description
Type

For a property, this is PropertyType. For a field, this is FieldType. The value is never null.

Methods

GetValue(object)

Reads the current value of this property or field from the specified object instance and returns it as an untyped object.

Declaration
public object GetValue(object instance)
Parameters
Type Name Description
object instance

The object whose member value should be read. Must be an instance of the type that declares this member; passing an incompatible type will cause the underlying delegate to throw a runtime exception.
Returns
Type Description
object

The boxed value of the member on instance, or null if the member holds a null reference.
Exceptions
Type Condition
InvalidOperationException

Thrown if CanRead is false or the internal getter delegate was not compiled (e.g., the property has no accessible getter).

IsDefaultValue(object)

Determines whether the specified value is equal to the language-default value for this member's Type.

Declaration
public bool IsDefaultValue(object value)
Parameters
Type Name Description
object value

The value to compare against DefaultValue. May be null.
Returns
Type Description
bool

true if value is structurally equal to DefaultValue (via Equals(object, object)), or if both are null; otherwise, false.
Remarks

Used by the serialization engine when DefaultValueHandling is set to Ignore to decide whether to omit a member from the serialized output.

SetValue(object, object)

Assigns the specified value to this property or field on the given object instance.

Declaration
public void SetValue(object instance, object value)
Parameters
Type Name Description
object instance

The object whose member should be updated. Must be an instance of the type that declares this member; passing an incompatible type will cause the underlying delegate to throw a runtime exception.
object value

The value to assign to the member. Must be assignment-compatible with Type; type mismatches will cause the underlying delegate to throw a runtime exception. Pass null to assign a null reference to a reference- type member.
Exceptions
Type Condition
InvalidOperationException

Thrown if CanWrite is false or the internal setter delegate was not compiled (e.g., the field is readonly).

Extension Methods

See Also