mapobject in dataweave ?166

 mapobject in dataweave ?

The mapobject function in DataWeave is used to iterate over the key-value pairs of an object and perform transformations on them. It's a powerful tool for manipulating the structure and content of data within your MuleSoft applications.

Here's a breakdown of what mapobject does:

Syntax:

mapobject<K, V>(object: { (K)?: V }, mapper: (value: V, key: K, index: Number) -> Object): Object

• <K, V>: Represents the generic types for keys and values in the object. In most cases, you can omit this part.

• object: The input object you want to iterate over.

• mapper: A lambda expression that defines how to transform each key-value pair.

• value: The value associated with the current key.

• key: The key itself.

• index: The zero-based index of the key-value pair within the object (optional).

• Returned value: A new object containing the transformed key-value pairs.

Key Points:

• The mapper lambda expression allows you to access and modify both the key and value of each element.

• You can modify the value, create a new key-value pair, or even remove the existing pair entirely within the mapper.

• The index parameter provides context for situations where the order of elements matters.

Here are some common use cases for mapobject:

• Renaming keys: Change the names of keys in the object.

• Transforming values: Apply DataWeave expressions to modify the values.

• Conditional transformations: Apply transformations based on specific conditions.

• Filtering key-value pairs: Include or exclude certain key-value pairs from the output based on criteria.

• Creating new key-value pairs: Generate new data based on existing values.

Example:

%dw 2.0
output = person |> mapobject { name:toupper(value), age: value * 2 }

---

{
  NAME: "JOHN",
  AGE: 40
}

In this example:

• We use mapobject to iterate over the person object.

• The mapper function converts the name value to uppercase and doubles the age value.

• The resulting output object has modified keys and transformed values.

By effectively using mapobject, you can achieve various data manipulation tasks within your MuleSoft applications using DataWeave's functional programming capabilities.