Convert properties from properties file into json in Dataweave 2.0 - mule

Question

How to convert properties from a properties file
creditmaster.metadata.AverageFicoScore=700
creditmaster.a.b.c=xyz
into this json format in a generic way
{
creditmasterMetaData: [
{
attributeKey: "AverageFicoScore",
attributeValue: 700
}
]
}

Answer 1

This script is generic in that it doesn't matter what are the parts of the key, it only groups by the first element (before of the first dot) and the key name after the last dot, it ignores everything in the middle:
%dw 2.3
output application/java
import * from dw::core::Strings
fun mapProperties(props) =
entriesOf(props) // since Mule 4.3 / DW 2.3
filter (substringAfter($.key, ".") startsWith "metadata.") // to filter keys with .metadata.
groupBy ((item, index) -> substringBefore(item.key, "."))
mapObject ((value, key, index) ->
(key): value map {
attributeKey: substringAfterLast($.key, "."),
attributeValue: if (isInteger($.value)) $.value as Number else $.value
}
)
---
mapProperties(payload)
Input file:
creditmaster.metadata.AverageFicoScore= 700
other.a.b= 123
creditmaster.a.b.c=xyz
something.metadata.another.maximum=456
creditmaster.metadata.different.minimum=500
Output (in JSON for clarity):
{
"something": [
{
"attributeKey": "maximum",
"attributeValue": "456"
}
],
"creditmaster": [
{
"attributeKey": "minimum",
"attributeValue": "500"
},
{
"attributeKey": "AverageFicoScore",
"attributeValue": "700"
}
]
}

Answer 2

One alternative is using the pluck function. It lets you iterate over an object receiving the entries.
If you have this input
{
"creditmaster": {
"metadata": {
"AverageFicoScore": "700",
"OtherData": "Some value"
}
}
}
with this transformation
{
creditmasterMetaData:
payload.creditmaster.metadata pluck ((value, key, index) ->
{
attributeKey: key,
attributeValue: value
}
)
}
you get this output
{
"creditmasterMetaData": [
{
"attributeKey": "AverageFicoScore",
"attributeValue": "700"
},
{
"attributeKey": "OtherData",
"attributeValue": "Some value"
}
]
}