constructing json in R with jsonlite - too many brackets - r

Question

Not a json expert, but I need what I think is referred to as "nested objects" and I am getting instead what I think is referred to as "nested arrays". In other words, some extra brackets. I'm trying to convert a dataframe into json data using jsonlite in R. Reproducible code and results below. Can anyone point me to how to get the data in the proper format (rows as nested objects)?
library(jsonlite)
testdat <- data.frame(locationColumn = c("US", "US"),
nameColumn = c("General Motors", "Walmart"),
zipColumn = c(19890, 72712) )
jsl <- jsonlite::toJSON(
list(
config = list(
item1 = list("country",
"city"),
item2 = "true",
item3 = "false",
item4 = 3
),
rows = split(testdat, 1:nrow(testdat))
),
auto_unbox = TRUE,
pretty = TRUE,
dataframe = "rows",
simplifyDataFrame = TRUE
)
jsl
Output:
{
"config": {
"item1": [
"country",
"city"
],
"item2": "true",
"item3": "false",
"item4": 3
},
"rows": {
"1": [
{
"locationColumn": "US",
"nameColumn": "General Motors",
"zipColumn": 19890
}
],
"2": [
{
"locationColumn": "US",
"nameColumn": "Walmart",
"zipColumn": 72712
}
]
}
}
What I need: (EDIT: I added some more complexity to the json. I need to keep the brackets in 'config', but not have brackets in 'rows'.
{
"config": {
"item1": [
"country",
"city"
],
"item2": "true",
"item3": "false",
"item4": 3
},
"rows": {
"1":
{
"locationColumn": "US",
"nameColumn": "General Motors",
"zipColumn": 19890
},
"2":
{
"locationColumn": "US",
"nameColumn": "Walmart",
"zipColumn": 72712
}
}
}

Answer 1

Here is a possible solution:
library(jsonlite)
testdat <- data.frame(locationColumn = c("US", "US"),
nameColumn = c("General Motors", "Walmart"),
zipColumn = c(19890, 72712) )
jsl <- jsonlite::toJSON(
list(
rows = split(testdat, 1:nrow(testdat))
),
auto_unbox = TRUE,
pretty = TRUE,
dataframe = "columns", #change from rows (moves brackets from row level to value level)
simplifyDataFrame = TRUE
)
#removed the backets if desired
#jsl<-gsub("\\[|\\]", "", jsl)
all.equal(testcase, fromJSON(jsl))
testcase<-fromJSON('{
"rows": {
"1":{
"locationColumn": "US",
"nameColumn": "General Motors",
"zipColumn": 19890
},
"2":{
"locationColumn": "US",
"nameColumn": "Walmart",
"zipColumn": 72712
}
}
}')
all.equal(testcase, fromJSON(jsl))
#[1] TRUE
EDIT Here is an approved version that manually edits the list of list in order to obtain the correct format.
#create a list of the data
top<-list(
config = list(
item1 = list("country",
"city"),
item2 = "true",
item3 = "false",
item4 = 3
),
rows = split(testdat, 1:nrow(testdat))
)
#edit the data frames store as part of rows
#lapply - lapply loops will parse each column in each row to create a new list
rows<-lapply(top$rows, function(x){
tempdf<-x
#collist<-lapply(names(tempdf), function(y){print(tempdf[ , y, drop=T])})
collist<-lapply(names(tempdf), function(y){tempdf[, y, drop=T]})
names(collist)<-names(tempdf)
collist
})
#update the list with the list of list
top$rows<-rows
#make the JSON
jsl <- jsonlite::toJSON(
top,
auto_unbox = TRUE,
pretty = TRUE,
dataframe = "columns",
simplifyDataFrame = TRUE
)