How to encode decode JSON objects in Redis Lua script?

Question

I am passing a JSON string to Lua script as an arg, I want to manuplate the JSON object to add some data and push to a queue.
How can I encode & decode the JSON objects in Redis Lua script?

Karthik Divi · Accepted Answer

Redis Lua scrip comes with the following packages by default

- base 
- table 
- string 
- math 
- struct 
- cjson 
- cmsgpack 
- bitop

we can use the `cjson` to do the marshalling and unmarshalling of JSON objects. 
Following code shows you how to do that

```lua 
local input = KEYS[1]
local json = cjson.decode(tostring(input))

-- work with json 
json.foo = 1

local output = cjson.encode(json);
return output
```

How to encode decode JSON objects in Redis Lua script?

2 Answers