Conversion of if/else based JSON by using Jolt - json

Question

I have two following json input and i want to convert it into expected output by jolt
input - 1
{
"alert_array": {
"alerts": [
{
"id": "1234",
"data": {
"parameter": [
{
"key": "level",
"value": "93.5"
}
]
}
}
]
}
}
input - 2
{
"alert_array": {
"alerts": [
{
"id": "1234",
"data": {}
}
]
}
}
expected output - 1
{
"alertArray": [
{
"id": "1234",
"properties": [
{
"key": "level",
"value": "93.5"
}
]
}
]
}
expected output - 2
{
"alertArray": [
{
"id": "1234",
"properties": []
}
]
}
In input-1 data contain some parameter but in input-2 data object is blank

Answer 1

You can use default transformation along with shift transformations
in order to add "properties": [] for the empty case of "data" object for the both of the input
JSON values such as
[
{
"operation": "shift",
"spec": {
"*": {
"alerts": {
"*": {
"id": "alertArray.&",
"*": {
"*": {
"*": {
"id": "alertArray.properties[&1].key",
"*": "alertArray.properties[&1].&"
}
}
}
}
}
}
}
},
{
"operation": "default",
"spec": {
"*": {
"properties": []
}
}
},
{
"operation": "shift",
"spec": {
"*": "&[]"
}
}
]
the demo for the first case :
the demo for the second case :
If there was no such need(to fill up for the "data"), then the following single spec would be sufficient :
[
{
"operation": "shift",
"spec": {
"*": {
"alerts": {
"*": {
"id": "alertArray[&1].&",
"*": {
"*": {
"*": {
"id": "alertArray[&4].properties[&1].key",
"*": "alertArray[&4].properties[&1].&"
}
}
}
}
}
}
}
}
]