The document discusses DataWeave and how it transforms input data into output data models. DataWeave defines the output data model using standard code which can produce simple values, arrays, or objects. Expressions in the DataWeave body generate one of these data types, and can be composed of other expressions. The output is always an object, array or simple value.

1. Mule Concepts
DataWeave IV

2. • Regardless of the input and output types, the data model for the output is
always described in standard DataWeave code.
• It is this model that the input is transformed into.
• The data model of the produced output could consist of three different
types of data:
– Simple Values
– Arrays: Represented as a sequence of comma separated values
– Objects: Represented as collection of key value pairs
• When you write code in the DataWeave body, you define an expression
that generates one of the data types listed above.
• Expressions can also be complex, meaning that they can be composed of
other expressions.
• Remember that each expression produces an Object, an Array, or a
Variable
DataWeave – Body

3. • Simple Values :
– Simple values can be of the following types:
• String : Double quoted ("Hello") or Single quoted ('Hello')
• Boolean : Literals true or false.
• Number : Decimal and Integer values are supported (ex: 2.0).
• Date : IS0-8601 enclosed by "|" (ex:|2003-10-01T23:57:59Z|).
• Regex : Regex expression enclosed by "/" (ex:/(d+)-(d+)/)
• Arrays :
– Arrays are represented as a sequence of value expressions.
– Example :
%dw 1.0 %output application/json --- [ "My", "three", "words" ]
• Objects :
– These are represented as a comma separated sequence of key: value pairs
surrounded by curly brackets { }.
DataWeave – Body

4. • Objects :
– Example :
– Both the keys and the values may be expressions.
DataWeave – Body
Transform Output
%dw 1.0
%output application/xml
---
myoutput:{
name : "Jill",
payload : payload.id + 3
}
<?xml version="1.0"
encoding="UTF-8"?>
<myoutput>
<name>Jill</name>
<payload>5</payload>
</myoutput>