R data frame to JSON Hierarchy - r

Question

I have the following data frame:
fakedat<-data.frame(name=c("Holdingcompany","Holdingcompany","company1","company1","company2","company2"),children=c("company1","company2","company4","company3","company5","company6"),info=c("text1","text2","text3","text5","othertext","other_text"),percentage=c("100%","100%","60%","75%","80%","70%"))
The output I am hoping is the following:
{"name": "Holdingcompany",
"children": [
{
"name": "company1",
"tooltip": "text1",
"percentage": "100%",
"children": [
{
"name": "company4",
"tooltip": "text3",
"percentage": "60%"
},
{
"name": "company3",
"tooltip": "text5",
"percentage": "75%"
}
]
},
{
"name": "company2",
"tooltip": "text2",
"percentage": "100%",
"children": [
{
"name": "company5",
"tooltip": "othertext",
"percentage": "80%"
},
{
"name": "company6",
"tooltip": "other_text",
"percentage": "70%"
}
]
}
]
}
I have attempted a couple different methods of parsing including:
How to write to json with children from R
But unfortunately I wasn't able to apply the above code to this situation properly to the the children in lists the way I was hoping.
Attempting to apply some of the solution from the below mentioned possible duplicate, I'm running into a recursion error: "C stack usage too close to limit" as the function appears to call itself.
##Adding in IDs
fakedat<-data.frame(id=c(1,2,3,4,5,6),name=c("Holdingcompany","Holdingcompany","company1","company1","company2","company2"),
children=c("company1","company2","company4","company3","company5","company6"),
info=c("text1","text2","text3","text5","othertext","other text"),
percentage=c("100%","50%","60%","75%","80%","70%"))
get_node <- function(df, id) {
node <- as.list(df[df$id == id, c("name", "info",
"percentage","id")])
names(node) = c("name", "info", "percentage","id")
id1<-df[df$id==id,]$children
if (!is.na(id1)){
child1 <- get_node(df, id)
if(child1$name == node$name){
node$children <- list(child1)}
node
}
}
jsonlite::toJSON(get_node(fakedat,6), pretty = TRUE, auto_unbox =
TRUE)`
Error: C stack usage 7972496 is too close to the limit

Answer 1

Consider preparing the relationships of parent to child with merge, then walk down each level of root / parent / child to build nested lists with nested lapply:
Data Preparation
### MERGE DATA
merge_df <- merge(fakedat, fakedat, by.x="children", by.y="name")
merge_df
# children name info.x percentage.x children.y info.y percentage.y
# 1 company1 Holdingcompany text1 100% company4 text3 60%
# 2 company1 Holdingcompany text1 100% company3 text5 75%
# 3 company2 Holdingcompany text2 100% company5 othertext 80%
# 4 company2 Holdingcompany text2 100% company6 other_text 70%
nested_df <- unique(merge_df[c("children", "name", "info.x", "percentage.x")])
nested_df
# children name info.x percentage.x
# 1 company1 Holdingcompany text1 100%
# 3 company2 Holdingcompany text2 100%
top_level_val <- unique(merge_df$name)
top_level_val
# [1] "Holdingcompany"
JSON Build
output <- lapply(top_level_val, function(root) {
root_lst <- list(
name = root
)
root_lst$children <- lapply(1:nrow(nested_df), function(i) {
chld_mrg <- merge(nested_df[nested_df$children == nested_df$children[i],], merge_df)
parent_lst <- list(
name = nested_df$children[i][1],
tooltip = nested_df$info.x[i][1],
percentage = nested_df$percentage.x[i][1]
)
parent_lst$children <- lapply(1:nrow(chld_mrg), function(j)
list(
name = merge_df$children.y[j][1],
tooltip = merge_df$info.y[j][1],
percentage = merge_df$percentage.y[j][1]
)
)
return(parent_lst)
})
return(root_lst)
})
# CONVERT TO JSON STRING
jdata <- toJSON(output[[1]], pretty=TRUE, auto_unbox=TRUE)
# WRITE TO DISK
fileConn <- file("NestParentChildJSON.json")
writeLines(jdata, fileConn)
close(fileConn)
Output
{
"name": "Holdingcompany",
"children": [
{
"name": "company1",
"tooltip": "text1",
"percentage": "100%",
"children": [
{
"name": "company4",
"tooltip": "text3",
"percentage": "60%"
},
{
"name": "company3",
"tooltip": "text5",
"percentage": "75%"
}
]
},
{
"name": "company2",
"tooltip": "text2",
"percentage": "100%",
"children": [
{
"name": "company4",
"tooltip": "text3",
"percentage": "60%"
},
{
"name": "company3",
"tooltip": "text5",
"percentage": "75%"
}
]
}
]
}