How to map certain keys of an array to make another one in mule 4 - mule

Question

I have an array -
[
{
"Number": "12345",
"abc": {
"group": "abc",
"operation": "Create"
},
"def": {
"group": "def",
"operation": "Create"
}
},
{
"Number": "45678",
"xyz": {
"group": "xyz",
"operation": "Update"
},
"sdf": {
"group": "sfd",
"operation": "Delete"
}
}
]
and need to convert into this form -
[
{
"Number": "12345",
"group": "abc",
"operation": "Create"
},
{
"Number": "12345",
"group": "def",
"operation": "Create"
},
{
"Number": "45678",
"group": "xyz",
"operation": "Update"
},
{
"Number": "45678",
"group": "sfd",
"operation": "Delete"
}
]
Trying to write dataweave expression for the same. The issue is that abc, def, xyz and all are objects which may or maynot come and can have different values.

Answer 1

Another way to handle this:
%dw 2.0
output application/json
---
payload flatMap ((item, index) ->
(item - "Number") pluck {
"Number": item.Number,
($)
}
)
The approach is mostly the same, but here is the explanation: we use map to iterate, but with flatMap instead since we know we will be returning multiple items from each instance. Then the first thing we do is remove the key Number from the item since we only want to build a new object for each key that isn't Number. Then we can pluck, which gives us access to each key and value; from here we build a new object with our item's number value, and expand the entire object we plucked into that object. When using an anonymous function like this, the $, $$, $$$, etc represent the functions parameters - in pluck's case value, key, index. The parentheses we put around $ means to expand the entire object into our object; in javascript this is similar to { ...props, anotherKey: 'value' }. This means we don't really need to know or care about the structure of that object, which is useful if we have a potentially flexible schema.

Answer 2

You need to map each element, then filter each object to eliminate the attribute Number, and use pluck to convert each remaining key into an array. I used flatMap to concatenate each resulting array from each pluck into the response.
%dw 2.0
output application/json
---
payload flatMap ((item, index) ->
item
filterObject ((value, key, index) -> !(key ~= "Number"))
pluck ((value, key, index) -> {Number: item.Number, group: value.group, operation: value.operation})
)