JSON pretty encode

bogdan · 2015-09-28T20:37:26+00:00

Hi folks The latest git master branch of lua-nginx-module now has the new *_by_lua_block {} directives. For example, instead of writing content_by_lua...

JSON pretty encode

bogdan

Hello, everybody

We need to encode a LUA data structure using JSON encoding, but in a human readable format, like this:

{

  "key1": "data",

  "key2": 27,

  "key3":
 {

    "key3_1": "something",

    "key3_2": "something
 else"

},

  "key4":
 [

    "item1",

    "item2"

]

}

Please note the indentation for each item in the data structure.

I found for this two libraries written in pure Lua:

The first one seems to be faster for encoding (according to this: http://lua-users.org/wiki/JsonModules), but anyhow much slower than other C-based libraries (like "cjson" already included in OpenResty).

This type of "human readable encoding" (or "pretty encoding") is used only in a few places in our application, so performance is not critical, but the output has to be compatible with the "cjson" library.

What would you recommend?

Thank you

Bogdan

aapo.talvensaari

On 28 September 2015 at 15:37, Bogdan Irimia <bo...@digitair.ro> wrote:

> We need to encode a LUA data structure using JSON encoding, but in a human readable format

How about this:

https://github.com/bungle/lua-resty-libcjson

bogdan

Wasn't clear for me if it formats the text as we need it.

Aapo Talvensaari wrote:

On 28 September 2015 at 15:37, Bogdan Irimia <bo...@digitair.ro
<mailto:bo...@digitair.ro>> wrote:

> We need to encode a LUA data structureusing JSON encoding, but
in a human readable format

How about this:
https://github.com/bungle/lua-resty-libcjso.

aapo.talvensaari

On Monday, 28 September 2015 16:04:42 UTC+3, bogdan wrote:
Wasn't clear for me if it formats the text as we need it.

It is easy to test:

print(json.encode({
  key1 = "data",
  key2 = 27,
  key3 = {
    key3_1 = "something",
    key3_2 = "something else"
  },
  key4 = {
    "item1",
    "item2"
  }
}, true)) 

This will output:

{
  "key1": "data", 
  "key3": { 
    "key3_1": "something", 
    "key3_2": "something else" 
 }, 
 "key2": 27, 
 "key4": ["item1", "item2"] 
}

Not sure though if this is what you wanted as ut seems you like to have each array item on their own line.

Regards

Aapo

bogdan

It'll do with arrays on one line. I tested it, works pretty ok for what we need.

Thank you

Aapo Talvensaari

Monday, September 28, 2015 4:37 PM via Postbox

On Monday, 28 September 2015 16:04:42 UTC+3, bogdan wrote:
Wasn't clear for me if it formats the text as we need it.

It is easy to test:

print(json.encode({ key1 = "data", key2 = 27, key3 = { key3_1 = "something", key3_2 = "something else" }, key4 = { "item1", "item2" } }, true))

This will output:

{ "key1": "data", "key3": { "key3_1": "something", "key3_2": "something else" }, "key2": 27, "key4": ["item1", "item2"] }

Not sure though if this is what you wanted as ut seems you like to have each array item on their own line.

Regards
Aapo
.

aapo.talvensaari

On Monday, 28 September 2015 16:39:05 UTC+3, bogdan wrote:
It'll do with arrays on one line. I tested it, works pretty ok for what we need

You may also check this:

https://github.com/bungle/lua-resty-prettycjson

I just wrote a simple pretty formatter for Lua cJSON in Lua (no extra dependencies). This does excatly what you wanted.

sparvu_71a1

> You may also check this:
> https://github.com/bungle/lua-resty-prettycjson
> 

10 x thanks. We will use that, less dependencies and no need for extra
binaries, shared libs.

-- 
Stefan Parvu <sp...@kronometrix.org>