Creating JSON format data through data frames in R -

i want create json data of form

{"recipe name": "abc", "main ingredient": "xyz", "ingredients": {type:"a"                  id:"1"},                {type:"b"                  id:"2"},                 {type:"b"                  id:"3"} "servings": 3,} 

i have data frame of type:

recipe, recipe id ,ingredients,ingredients id,servings ,main ingredient,main ingredient id    "abc"  , 2     ,    {"a","b","c"}  , {1,2,3,}   , 5   , "f"   ,7      "bcf"  , 3   ,       {"d","e","f"} , {4,5,7}  ,  4    ,"g"   ,8    .... 

i have tried usign rjson package got character(0) output .can me please ?

i did find 1 method though

>library(rjsonio) >tojson(dataframe) 

here output:

[1] "{\n \"factor1\": [ \"115g\", \"1\", null, null ],\n\"unit1\": [ \"tub\", \"cups\", \"greek\", \"baby\" ],\n\"item1\": [ \"tomatoes na\", \"kalamata olives\", \"feta cheese\", \"rocket na\" ] \n}"

which not in required format

your desired output isn't correctly structured: missing commas (minor), , ingredients needs explicit list (using [ , ], nothing implicit allowed). also, r doesn't enjoy spaces in column names, removed them. restructured output:

{"recipename": "abc",  "mainingredient": "xyz",  "ingredients": [{"type":"a", "id":"1"},                  {"type":"b", "id":"2"},                  {"type":"b", "id":"3"}],  "servings": 3} 

since data.frame example bit difficult read/parse, here 1 similar enough, think:

dat <- data.frame(     recipename=c('abc', 'def'),     mainingredient=c('xyz', 'lmn'),     ingredients=c('{"a","b","c"}', '{"d","e","f"}'),     ingredientsid=c('{1,2,3}', '{4,5,6}'),     servings=c(7,8),     stringsasfactors=false ) dat ##   recipename mainingredient   ingredients ingredientsid servings ## 1        abc            xyz {"a","b","c"}       {1,2,3}        7 ## 2        def            lmn {"d","e","f"}       {4,5,6}        8 

from here, takes little effort convert nested lists within ingredients more string:

datlist <- as.list(dat) datlist$ingredients <- mapply(function(a,b) {     a1 <- strsplit(substring(a, 2, nchar(a)-1), ",")[[1]]     ## might want remove leading/trailing quotes     a1 <- gsub('"', '', a1)     b1 <- strsplit(substring(b, 2, nchar(b)-1), ",")[[1]]     mapply(function(e,f) list(type=e, id=f), a1, b1, simplify=false, use.names=false) }, datlist$ingredients, datlist$ingredientsid,     simplify=false, use.names=false) datlist$ingredientsid <- null # remove now-unnecessary field  library(rjsonio) # jsonlite::tojson looks similar, not same cat(tojson(datlist, pretty=t)) ## { ##  "recipename" : [ ##      "abc", ##      "def" ##  ], ##  "mainingredient" : [ ##      "xyz", ##      "lmn" ##  ], ##  "ingredients" : [ ##      [ ##          { ##              "type" : "a", ##              "id" : "1" ##          }, ##          { ##              "type" : "b", ##              "id" : "2" ##          }, ##          { ##              "type" : "c", ##              "id" : "3" ##          } ##      ], ##      [ ##          { ##              "type" : "d", ##              "id" : "4" ##          }, ##          { ##              "type" : "e", ##              "id" : "5" ##          }, ##          { ##              "type" : "f", ##              "id" : "6" ##          } ##      ] ##  ], ##  "servings" : [ ##      7, ##      8 ##  ] ## }>  

unfortunately, taking single row data.frame results in nested components (specifically ingredients), not adhere desired output:

datlist2 <- as.list(dat[1,]) ## rest of mapply(mapply(...)) ... cat(tojson(datlist2, pretty=true)) ## { ##  "recipename" : "abc", ##  "mainingredient" : "xyz", ##  "ingredients" : [ ##      [ ##          { ##              "type" : "a", ##              "id" : "1" ##          }, ##          { ##              "type" : "b", ##              "id" : "2" ##          }, ##          { ##              "type" : "c", ##              "id" : "3" ##          } ##      ] ##  ], ##  "servings" : 7 ## }