heading top-level property
Codec to convert HeadingModifier to/from JSON (see DocumentJsonCodec).
Implementation
final heading = LineModifierCodec<HeadingModifier>.stateful(
typeStr: 'heading',
encode: (mod) => mod.level,
decode: (level) {
if (level is! int) {
throw Exception('Expected integer as data for heading attribute.');
}
return HeadingModifier(level);
},
);