Jolt Transform to append extracted data - json

Question

I'm new to Jolt Transform and have some EDI data that I want to transform. I want to keep the original data and append a few extracted elements in order to make it easier for a downstream process to get to. Here's a sample:
Input
{
"id": "2000",
"segments": [
{
"REF02": "xxxxxxxxxxxx",
"REF01": "0F",
"id": "REF"
},
{
"REF02": "yyyyyyyyyyyy",
"REF01": "1L",
"id": "REF"
}
],
"loops": [
{
"id": "2100",
"segments": []
},
{
"id": "2100",
"segments": [],
"loops": [
{
"id": "2300",
"segments": [
{
"DTP01": "348",
"DTP03": "20220101",
"DTP02": "D8",
"id": "DTP"
},
{
"DTP01": "349",
"DTP03": "20221231",
"DTP02": "D8",
"id": "DTP"
}
]
}
]
}
]
}
Desired Output
{
"ext": {
"subscriber": "xxxxxxxxxxxx",
"start": "20220101"
},
"id": "2000",
"segments": [
{
"REF02": "xxxxxxxxxxxx",
"REF01": "0F",
"id": "REF"
},
{
"REF02": "yyyyyyyyyyyy",
"REF01": "1L",
"id": "REF"
}
],
"loops": [
{
"id": "2100",
"segments": []
},
{
"id": "2100",
"segments": [],
"loops": [
{
"id": "2300",
"segments": [
{
"DTP01": "348",
"DTP03": "20220101",
"DTP02": "D8",
"id": "DTP"
},
{
"DTP01": "349",
"DTP03": "20221231",
"DTP02": "D8",
"id": "DTP"
}
]
}
]
}
]
}
That is, I'd like to append the ext element - copying values from the original.
In xpath terms, the extracted values' paths look something like this:
subscriber :
/segments[../id eq "2000"]/..[REF01 eq "0F"]/REF02/text()
start :
/loops[../id eq "2000"]/../segments[../id eq "2100"])[1]/..
[id eq "NM1" and NM101 eq "IL"][DTP01 eq "348"]/DTP03/text()
Thanks for the help.

Answer 1

I ended up with this solution. If there's any feedback on streamlining, making more elegant, let me know.
[
{
"operation": "default",
"spec": {
"dummy": {}
}
},
{
"operation": "shift",
"spec": {
"dummy": {
"#2,segments": {
"*": {
"REF01": {
"0F": {
"#2,REF02": "ext.subscriber"
}
}
}
},
"#2,loops": {
"*": {
"id": {
"2100": {
"#2,loops": {
"*": {
"id": {
"2300": {
"#2,segments": {
"*": {
"DTP01": {
"348": {
"#2,DTP03": "ext.start"
}
}
}
}
}
}
}
}
}
}
}
}
},
"id": "id",
"segments": "segments",
"loops": "loops"
}
}
]

Answer 2

You can replicate the whole content by use of "#": "" within a shift transformation while adding less curly braces to nest the inner stuff, at the same time determining the paths to search to be used in the next spec such as
[
{
"operation": "shift",
"spec": {
"#": "",
"segments": {
"*": {//indexes of the array
"#REF02": "ext.su.#REF01"
}
},
"loops": {
"*": {//indexes of the array
"#loops": {
"*": {//indexes of the array
"#segments": {
"*": {//indexes of the array
"#DTP03": "ext.st.#5,id.#3,id.#DTP01"
}
}
}
}
}
}
}
},
{
"operation": "shift",
"spec": {
"ext": {
"#su.0F": "&1.subscriber",
"#st.2100.2300.348": "&1.start"
},
"*": "&" //replicate the other attributes/arrays/objects
}
}
]