JSON.Lua json.encode return nil - json

Question

I'm new to LUA and tried learning coding this language with Garrys Mod.
I want to get the messages from the Garrys Mod chat and send them into a Discord channel with a webhook.
It works, but I tried expanding this project with embeded messages. I need JSON for this and used json.lua as a library.
But as soon as I send a message I retrieve the following error message:
attempt to index global 'json' (a nil value)
The code that causes the error is the following:
json.encode({ {
["embeds"] = {
["description"] = text,
["author"] = {
["name"] = ply:Nick()
},
},
} }),
The complete code:
AddCSLuaFile()
json = require("json")
webhookURL = "https://discordapp.com/api/webhooks/XXX"
local DiscordWebhook = DiscordWebhook or {}
hook.Add( "PlayerSay", "SendMsg", function( ply, text )
t_post = {
content = json.encode({ {
["embeds"] = {
["description"] = text,
["author"] = {
["name"] = ply:Nick()
},
},
} }),
username = "Log",
}
http.Post(webhookURL, t_post)
end )
I hope somebody can help me

Answer 1

Garry's Mod does provide two functions to work with json.
They are:
util.TableToJSON( table table, boolean prettyPrint=false )
and
util.JSONToTable( string json )
There is no need to import json and if I recall correctly it isn't even possible.
For what you want to do you need to build your arguments as a table like this:
local arguments = {
["key"] = "Some value",
["42"] = "Not always the answer",
["deeper"] = {
["my_age"] = 22,
["my_name"] = getMyName()
},
["even more"] = from_some_variable
and then call
local args_as_json = util.TableToJSON(arguments)
Now you can pass args_as_json to your
http.Post( string url, table parameters, function onSuccess=nil, function onFailure=nil, table headers={} )