Updated 2016-06-28 08:02:30 by juef

The Tcllib JSON module provides a parser and a generator. The parser is in the namespace ::json, the generator is in the namespace ::json::write. Both form an "ensemble command".

Reference  edit

json (alternate)
json::write (alternate)

json2prettydict Patch  edit

ABU 2012-04-18:

Few weeks ago I posted a patch-proposal [1] for the json package.

I added a new proc named json2prettydict. Aim of this proc is to return a "pretty-printed" tcl-dictionary

I think this proc could be useful for documenting complex nested dictionaries.

Here is an example:
set jsonStr { \
  { "photos": { "page": 1, "pages": "726", "perpage": 3, "total": "7257", 
    "photo": [
      { "id": "6974156079", "owner": "[email protected]", "secret": "005d743f82", "server": "7197", "farm": 8, "title": "Kenya Watamu \"Deep Sea Fishing\" \"Indian Ocean\" \"Blue Marlin\"", "ispublic": 1, "isfriend": 0, "isfamily": 0 },
      { "id": "6822988100", "owner": "[email protected]", "secret": "56630c18e8", "server": "7183", "farm": 8, "title": "Gedi Ruins, Local Guide", "ispublic": 1, "isfriend": 0, "isfamily": 0 },
      { "id": "6822909640", "owner": "[email protected]", "secret": "f4e392ea36", "server": "7063", "farm": 8, "title": "Local Fisherman, Mida Creek", "ispublic": 1, "isfriend": 0, "isfamily": 0 }
    ] }, "stat": "ok" }
}

First, just for comparision, call json2dict
set d1 [json::json2dict $jsonStr]

result is the following
photos {page 1 pages 726 perpage 3 total 7257 photo {{id 6974156079 owner [email protected] secret 005d743f82 server 7197 farm 8 title {Kenya Watamu "Deep Sea Fishing" "Indian Ocean" "Blue Marlin"} ispublic 1 isfriend 0 isfamily 0} {id 6822988100 owner [email protected] secret 56630c18e8 server 7183 farm 8 title {Gedi Ruins, Local Guide} ispublic 1 isfriend 0 isfamily 0} {id 6822909640 owner [email protected] secret f4e392ea36 server 7063 farm 8 title {Local Fisherman, Mida Creek} ispublic 1 isfriend 0 isfamily 0}}} stat ok

then create a pretty printed dictionary
set d2 [json::json2prettydict $jsonStr]

result is still a valid tcl-dict, just more readable
photos {
    page 1
    pages 726
    perpage 3
    total 7257
    photo {
        {
            id 6974156079
            owner [email protected]
            secret 005d743f82
            server 7197
            farm 8
            title {Kenya Watamu "Deep Sea Fishing" "Indian Ocean" "Blue Marlin"}
            ispublic 1
            isfriend 0
            isfamily 0
        }
        {
            id 6822988100
            owner [email protected]
            secret 56630c18e8
            server 7183
            farm 8
            title {Gedi Ruins, Local Guide}
            ispublic 1
            isfriend 0
            isfamily 0
        }
        {
            id 6822909640
            owner [email protected]
            secret f4e392ea36
            server 7063
            farm 8
            title {Local Fisherman, Mida Creek}
            ispublic 1
            isfriend 0
            isfamily 0
        }
    }

}
stat ok

EF For an experiment on how to access data from the "parsed tree" (which really are dictionaries), see Playing XPath with JSON.

Performance  edit

dbohdan 2015-03-23: Tcllib JSON gets a significant speed boost from [jsonc] if you have [tcllibc] and critcl installed.

Change Log  edit

JH 2006-08-17: I have made the JSON parser functional and moved it into tcllib (see http://tcllib.cvs.sourceforge.net/tcllib/tcllib/modules/json/). I started with what CMcC had here, but rewrote it for correctness and improved speed.