JSON

require("internal.json") serialises Lua values to JSON and back. It is a built-in module, available in every script kind.

local json = require("internal.json")

json.encode(value)

local str = json.encode({ key = "value", items = { 1, 2, 3 } })
-- '{"key":"value","items":[1,2,3]}'

Converts a Lua value to a JSON string. A table with consecutive integer keys from 1 encodes as an array; any other table encodes as an object.

json.decode(string)

local tbl = json.decode('{"key": "value"}')
-- tbl.key == "value"

Parses a JSON string into a Lua value. Raises when the input is not valid JSON.

json.to_array(table)

return { items = json.to_array(results) }
-- With results:    {"items": [{"name": "a"}, {"name": "b"}]}
-- Without results: {"items": []}

Marks a table so it always encodes as a JSON array. Lua does not distinguish an empty array from an empty object, so an empty {} encodes as {} unless it is marked. Pages and record lists returned by a library are already marked; mark a table you build yourself with table.insert or index assignment, whether it is returned from handle or passed to json.encode.