<sc-union> — Custom Element renderer for plain UnionField.
Mirrors React's renderUnion: picks the structurally matching option
via matchUnionOption and delegates to renderChild. Falls
back to the first option when no match is found, or to the em-dash
placeholder when the union has no options.
<sc-union>— Custom Element renderer for plainUnionField.Mirrors React's
renderUnion: picks the structurally matching option via matchUnionOption and delegates torenderChild. Falls back to the first option when no match is found, or to the em-dash placeholder when the union has no options.Parts:
value.