Slap.Yjs.Awareness (slap_yjs v0.4.0)

Copy Markdown View Source

Encodes and decodes awareness (presence) updates in the y-protocols format. An update starts with its entry count as a varuint. Each entry contains a client id and clock as varuints, then a length-prefixed JSON state; "null" removes the client's state.

A host can use decode/1 to check the awareness messages its clients send, and encode/1 to build an update from the entries it accepts. The README's "Authorizing client awareness" section shows how. To publish and maintain awareness for a server-side participant, use Slap.Yjs.Presence.

Summary

Types

entry()

Functions

decode(update)

Decodes an awareness update into entries. A removal has a nil state. Returns {:error, :invalid} for malformed updates.

encode(entries)

Encodes entries into an awareness update.

Types

entry()

@type entry() ::
  {client_id :: non_neg_integer(), clock :: non_neg_integer(), state :: term()}

Functions

decode(update)

@spec decode(binary()) :: {:ok, [entry()]} | {:error, :invalid}

Decodes an awareness update into entries. A removal has a nil state. Returns {:error, :invalid} for malformed updates.

A complete awareness message is byte 1 followed by a framed update. This function accepts only the unframed update.

encode(entries)

@spec encode([entry()]) :: binary()

Encodes entries into an awareness update.