How to convert all the keys in an object to uppercase ? in MuleSoft 117

Wednesday 13 March 2024

How to convert all the keys in an object to uppercase ? in MuleSoft

There are two primary methods to convert all keys in an object to uppercase within MuleSoft 4:

1. Using DataWeave:

DataWeave offers a powerful approach for manipulating objects and their properties. Here's how to achieve the conversion:

%dw 2.0
---
output = message.payload mapObject ((key, value) -> { (upper(key)): value })

Explanation:

The mapObject function iterates over each key-value pair in the original payload object.
Within the function, a new object is constructed.
The key is converted to uppercase using the upper function.
The original value is retained.
The final output variable holds the new object with all keys in uppercase.

2. Using MEL (Message Expression Language):

While less flexible than DataWeave, MEL can be used for this specific task. Here's the approach:

XML

#[(payload map { (key: k, value: v) -> [MULE_UTIL:upper(k)]: v })]

Explanation:

The expression utilizes a custom function using MULE_UTIL:upper to convert the key to uppercase within the anonymous function.
Similar to DataWeave, a new map is created, iterating over each key-value pair.
The uppercase key becomes the new key in the resulting map.

Choosing the Right Approach:

DataWeave: This is the recommended method due to its readability, maintainability, and broader data manipulation capabilities.
MEL: While functional for this specific scenario, MEL can become cumbersome for complex data transformations.

Additional Notes:

Ensure the payload is a valid JSON object before applying these methods.
Error handling can be incorporated within DataWeave or MEL to handle cases where the payload might not be in the expected format.

Here are some helpful resources for further exploration: