class

JsonWriter

@Js
class JsonWriter : Obj

Write Haystack data in JSON format.

 constructors make

Wrap output stream

 fields opts

 methods valToStr

Get a value as a JSON string

 writeGrid

Write the grid and return this

 writeVal

Write any haystack value

 flush

Flush the underlying output stream and return this

 close

Close the underlying output stream

 close Bool close()

Close the underlying output stream

 flush This flush()

Flush the underlying output stream and return this

 make new make(OutStream out, Dict? opts)

Wrap output stream. By default, the writer encodes JSON in the Haystack 4 (Hayson) format. Use the v3 option to encode JSON in the Haystack 3 format.

The following opts are supported:

  • v3 (Marker): write JSON in the Haystack 3 format
JsonWriter(out).writeVal(Etc.makeDict(["ts": DateTime.now])).close

JsonWriter(out, Etc.makeDict(["v3":Marker.val])).writeGrid(grid).close

 opts Dict : opts

valToStr static Str valToStr(Obj? val)

Get a value as a JSON string.

 writeGrid virtual This writeGrid(Grid grid)

Write the grid and return this

 writeVal This writeVal(Obj? val)

Write any haystack value

 Haxall 4.0.5 ∙ 24-Feb-2026 14:33 EST