app.json - JSON API

JSON encoding and decoding.

Methods

app.json.parse(jsonString)

Parses a JSON string into a Lua table.

Parameters:

• jsonString (string) - JSON string

Returns: any|nil - Lua value or nil (on parse failure)

local data = app.json.parse('{"name": "test", "count": 123}')
-- { name = "test", count = 123 }

local arr = app.json.parse('[1, 2, 3]')
-- { 1, 2, 3 }

app.json.stringify(value, pretty?)

Converts a Lua value to a JSON string.

Parameters:

• value (any) - Value to convert (table, string, number, etc.)
• pretty (boolean, optional) - Whether to format the output (default false)

Returns: string|nil - JSON string or nil

-- Compact format
local json = app.json.stringify({name = "test", count = 123})
-- '{"name":"test","count":123}'

-- Pretty format
local json = app.json.stringify({name = "test", count = 123}, true)
-- {
--   "count": 123,
--   "name": "test"
-- }

app.json.readFile(path)

Reads and parses JSON from a file.

Parameters:

• path (string) - JSON file path

Returns: any|nil - Lua value or nil

local config = app.json.readFile("/path/to/config.json")
if config then
    app.log.info("Config: " .. config.name)
end

app.json.writeFile(path, value, pretty?)

Writes a Lua value to a JSON file.

Parameters:

• path (string) - File path
• value (any) - Value to write
• pretty (boolean, optional) - Whether to format (default false)

Returns: boolean - Whether successful

app.json.writeFile("/path/to/output.json", {
    name = "test",
    items = {1, 2, 3}
}, true)

Type Mapping

Examples

Reading a Configuration File

function MyPlugin:loadConfig()
    local configPath = app.path.join(app.context.pluginDirectory(), "config.json")

    if not app.path.exists(configPath) then
        -- Create default configuration
        self.config = {
            version = "1.0.0",
            settings = {
                quality = 90,
                format = "PNG"
            }
        }
        app.json.writeFile(configPath, self.config, true)
    else
        self.config = app.json.readFile(configPath)
    end
end

Processing an API Response

function MyPlugin:fetchData(url)
    local response = app.http.get(url)

    if not response or response.status ~= 200 then
        app.log.error("Request failed")
        return nil
    end

    local data = app.json.parse(response.body)
    if not data then
        app.log.error("JSON parse failed")
        return nil
    end

    return data
end