Mule Transformers can alter message properties, variables, or payloads to prepare them for further processing. Standard transformers are provided to handle common data conversion scenarios, such as XML-to-Object. If no single transformer achieves the needed output, multiple transformers can be used sequentially. Transformer categories include those for Java Objects, Content, SAP, Scripting, Properties/Variables/Attachments. The DataWeave transformer provides powerful data querying and transformation capabilities.

1. Mule Transformers

2. Instructions
• Prepares a message for further processing by
enhancing or altering the contents of the
message properties, variables, or payload
• Use a pre-built transformer to perform a
standard data conversion

3. Example
• Message source in a flow receives data in XML
format, but a downstream message processor
expects a Java object
• Use an XML-to-Object transformer to convert
the format of the message payload

4. Transformer Library
• Mule provides a set of standard transformers
to handle the most common data
transformation scenarios
• If Mule doesn’t have the particular
transformer, can arrange several transformers
in a sequence to achieve the output you need

5. Transformer Library Example
• Implement an A-to-C transformation but no such
transformer exists
• Arrange a sequence – A-to-B, B-to-C – which
effectively simulates an A-to-C transformer
• Example:
– convert XML to JSON, use an XML-to-Object
transformer followed by an Object-to-JSON
transformervely simulates an A-to-C transformer

6. Transformers categories - Java Object
• Each transformer in this group changes a Java
object into another Java object
• A Java object into a non-Java data type (such
as an HTTP request), or vice versa
• Example Transformers:
– JSON to Object
– XML to Object

7. Transformers categories - Content
• Transformers modifies messages by adding to,
deleting from, or converting a message
payload
• Example Transformers:
– Append String
– Expression
– Parse Template
– XSLT

8. Transformers categories - SAP
• Change SAP objects (JCo functions or IDoc
documents) into XML representations, or vice
versa
• Example Transformers:
– SAP Object to XML
– XML to SAP Function (BAPI)
– XML to SAP IDoc

9. Transformers categories - Script
• Utilizes a custom script to perform the
transformation
• Just add one of these to your flow, then write a script
in your favorite language to convert data as needed
• Example Transformers:
– Groovy
– JavaScript
– Python
– Ruby
– Script

10. Transformers categories - Properties,
Variables, and Attachments
• Add, remove, or copy properties, variables, and
attachments on the message
• Message processors doesn’t so much transform as
manipulate or enrich the contents of the message
header
• Example Transformers:
– Attachment
– Property
– Session Variable
– Variable

11. DataWeave Transformer
• Overview DataWeave:
– Simple, powerful tool used to query and transform data
inside of Mule
– Supports a variety of transformations: simple one-to-one,
one-to-many or many-to-one mappings from an
assortment of data structures

12. DataWeave Transformer
• Map an input field, such as last_name, to a different
output field, such as family_name
• Map multiple fields, such as title, first_name, and last_name,
to a composite output field such as full_name
• Retrieve session state information in a message to
facilitate conditional message routing
• Evaluation to facilitate conditional value recalculation
• Look up information in tables or other flows

13. Question and answer