Struct NoteAttachment 

pub struct NoteAttachment { /* private fields */ }

The optional attachment for a Note.

An attachment is a public extension to a note’s NoteMetadata.

Example use cases:

• Communicate the NoteDetails of a private note in encrypted form.
• In the context of network transactions, encode the ID of the network account that should consume the note.
• Communicate details to the receiver of a private note to allow deriving the NoteDetails of that note. For instance, the payback note of a partial swap note can be private, but the receiver needs to know additional details to fully derive the content of the payback note. They can neither fetch those details from the network, since the note is private, nor is a side-channel available. The note attachment can encode those details.

These use cases require different amounts of data, e.g. an account ID takes up just two felts while the details of an encrypted note require many felts. To accommodate these cases, both a computationally efficient NoteAttachmentContent::Word as well as a more flexible NoteAttachmentContent::Array variant are available. See the type’s docs for more details.

Next to the content, a note attachment can optionally specify a NoteAttachmentScheme. This allows a note attachment to describe itself. For example, a network account target attachment can be identified by a standardized type. For cases when the attachment scheme is known from content or typing is otherwise undesirable, NoteAttachmentScheme::none can be used.

Implementations

impl NoteAttachment

pub fn new( attachment_scheme: NoteAttachmentScheme, content: NoteAttachmentContent, ) -> Result<Self, NoteError>

Creates a new NoteAttachment from a user-defined type and the provided content.

Errors

Returns an error if:

• The attachment content is NoteAttachmentKind::None but the scheme is not NoteAttachmentScheme::none.

pub fn new_word(attachment_scheme: NoteAttachmentScheme, word: Word) -> Self

Creates a new note attachment with content NoteAttachmentContent::Word from the provided word.

pub fn new_array( attachment_scheme: NoteAttachmentScheme, elements: Vec<Felt>, ) -> Result<Self, NoteError>

Creates a new note attachment with content NoteAttachmentContent::Array from the provided set of elements.

Errors

Returns an error if:

• The maximum number of elements exceeds NoteAttachmentArray::MAX_NUM_ELEMENTS.

pub fn attachment_scheme(&self) -> NoteAttachmentScheme

Returns the attachment scheme.

pub fn attachment_kind(&self) -> NoteAttachmentKind

Returns the attachment kind.

pub fn content(&self) -> &NoteAttachmentContent

Returns a reference to the attachment content.

Trait Implementations

impl Clone for NoteAttachment

fn clone(&self) -> NoteAttachment

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NoteAttachment

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for NoteAttachment

fn default() -> NoteAttachment

Returns the “default value” for a type.

impl Deserializable for NoteAttachment

fn read_from<R: ByteReader>( source: &mut R, ) -> Result<Self, DeserializationError>

Reads a sequence of bytes from the provided source, attempts to deserialize these bytes into Self, and returns the result.

fn read_from_bytes(bytes: &[u8]) -> Result<Self, DeserializationError>

Attempts to deserialize the provided bytes into Self and returns the result.

impl PartialEq for NoteAttachment

fn eq(&self, other: &NoteAttachment) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serializable for NoteAttachment

fn write_into<W: ByteWriter>(&self, target: &mut W)

Serializes self into bytes and writes these bytes into the target.

fn to_bytes(&self) -> Vec<u8>

Serializes self into a vector of bytes.

fn get_size_hint(&self) -> usize

Returns an estimate of how many bytes are needed to represent self.

impl Eq for NoteAttachment

impl StructuralPartialEq for NoteAttachment