lexical_file

The .lexical document envelope for lexical_core — wire-compatible with @lexical/file, so a file saved here opens in the Lexical playground and the other way round. Pure Dart.

dependencies:
  lexical_file: ^1.0.0

// Save.
final document = serializedDocumentFromEditorState(
  editor.editorState,
  source: 'Hinata',
);
await File(suggestedDocumentFileName()).writeAsString(document.encode());

// Open.
final opened = SerializedDocument.parse(await file.readAsString());
editor.setEditorState(editorStateFromSerializedDocument(editor, opened));

The format

{
  "editorState": { "root": { "children": [], "type": "root", "version": 1 } },
  "lastSaved": 1753488000000,
  "source": "Lexical",
  "version": "0.48.0"
}

Four fields, and only editorState carries content. lastSaved is epoch milliseconds in UTC, source names the application that wrote the file, and version records the Lexical version whose format it is. A file missing the metadata still opens: losing the name of the writer is not worth losing the user's text over.

Why parsing and installing are two calls

final opened = SerializedDocument.parse(text);            // may throw
editor.setEditorState(editorStateFromSerializedDocument(editor, opened));

A file that turns out to be corrupt should leave the document the user already has open exactly as it was. Every failure is a typed MalformedDocumentException, thrown before anything is installed.

Node types are resolved through the editor's registry, which is why editorStateFromSerializedDocument takes one: the same image type may be a different class in two applications. A type the editor does not know follows its UnknownNodePolicy — preserve lets an older client round-trip a newer document without losing what it cannot render.

What this package deliberately does not do

@lexical/file also ships the browser half: a download link and a file input. There is no Flutter counterpart to those, and the right answer differs per platform — dart:io on a server, a share sheet on iOS, an anchor element on web. So this package is the data and nothing else; the bytes are yours to move.

Licence

MIT. Derived from Lexical, © Meta Platforms, Inc. See NOTICE.