Dynamically Map Based on a Definition

You can create a transformation that can dynamically change what it does depending on a definition input. This DataWeave example receives both a payload input, and a variable named mappings that specifies how to rename each field and what default value to use in each. Before you begin, note that DataWeave version 2 (%dw 2.0) is for Mule 4 apps. For a Mule 3 app, refer to DataWeave version 1 (%dw 1.0) examples, within the Mule 3.9 documentation set. For other Mule versions, you can use the Mule Runtime version selector in the table of contents.

The example uses the following:

A map function to go through all of the elements in the input array. Also a second map function to go through each field in each element.
A custom function that applies the changes specified in the mappings variable.
default to set a default value, that comes from the mappings variable.

DataWeave Script:

%dw 2.0
output application/json
var applyMapping = (in, mappingsDef) -> (
   mappingsDef map (def) -> {
    (def.target) : in[def.source] default def."default"
  }
)
---
payload.sfdc_users.*sfdc_user map (user) -> (
        applyMapping(user, vars.mappings)
)

Input XML Payload:

<sfdc_users>
    <sfdc_user>
      <sfdc_name>Mariano</sfdc_name>
      <sfdc_last_name>Achaval</sfdc_last_name>
      <sfdc_employee>true</sfdc_employee>
    </sfdc_user>
    <sfdc_user>
      <sfdc_name>Julian</sfdc_name>
      <sfdc_last_name>Esevich</sfdc_last_name>
      <sfdc_employee>true</sfdc_employee>
    </sfdc_user>
    <sfdc_user>
      <sfdc_name>Leandro</sfdc_name>
      <sfdc_last_name>Shokida</sfdc_last_name>
    </sfdc_user>
</sfdc_users>

Input JSON Mule Event Variable (vars.mappings):

[
  {
    "source": "sfdc_name",
    "target": "name",
    "default": "---"
  },
  {
    "source": "sfdc_last_name",
    "target": "lastName",
    "default": "---"
  },
  {
    "source": "sfdc_employee",
    "target": "user",
    "default": true
  }
]

Output JSON:

[
  [
    {"name": "Mariano"},
    {"lastName": "Achaval"},
    {"user": "true"}
  ],
  [
    {"name": "Julian"},
    {"lastName": "Esevich"},
    {"user": "true"}
  ],
  [
    {"name": "Leandro"},
    {"lastName": "Shokida"},
    {"user": true}
  ]
]

Dynamically Map Based on a Definition

Related Examples

See Also