Dataweave Tricks: Extract Keys and Values From HashMap

Introduction

I have a requirement to extract the keys and values from a dataset like the following:

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

{   "account1" : {       "accountID" : "1234",       "name" : "Mary Loo",       "balance" : 234.32      },   "account2" : {       "accountID" : "1234",       "name" : "Lauren Flor",       "balance" : 234.32      },   "account3" : {       "accountID" : "1234",       "name" : "Mary Loo",       "balance" : 234.32      }         }

Apparently, the above data is a Map. Now we need to produce two dataset of values and keys from the input (Map) as the following:

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

[     {         "accountID": "1234",         "name": "Mary Loo",         "balance": 234.32     },     {         "accountID": "1234",         "name": "Lauren Flor",         "balance": 234.32     },     {         "accountID": "1234",         "name": "Mary Loo",         "balance": 234.32     } ]

and

?

1 2 3 4 5

[     "account1",     "account2",     "account3" ]

Understanding Dataweave pluck Function

Dataweave has devised a function particularly for this kind of requirement. Here is the solution to extract values of a HashMap

?

1 2 3 4

%dw 2.0 output application/json --- payload pluck (item, key, index) -> item

The shorthand version:

?

1 2 3 4

%dw 2.0 output application/json --- payload pluck $

And to extract the keys:

?

1 2 3 4

%dw 2.0 output application/json --- payload pluck (item, key, index) -> key

The shorthand version:

?

1 2 3 4

%dw 2.0 output application/json --- payload pluck $$