These are the presentation slides for the sixth Mulesoft Meetup held in Huddersfield. The topics include covering RAML design - a comparison of queryParams vs queryStrings and Dataweave 2.0

1. 07/11/2019: DataWeave 2.0 & RAML, Integrating Design
with Development
West Yorkshire MuleSoft Meetup
Group

2. All contents © MuleSoft Inc.
Agenda
2
• Introductions
• Who are the organizers? / Introductions
• Guest speaker Ven: DataWeave
• Networking & Food
• Francis: RAML Integrating Design and Development
• What’s next
• Freebies

3. All contents © MuleSoft Inc.
Introductions
3
• About the organizers:
– The integration team in Saint Gobain Building Distribution have been actively developing
business applications within MuleSoft for over three years now.
– The team provides integrations between different corporate systems as well as to external
third parties and have replaced numerous file transfer integrations, automated scripts &
exposed APIs for the Digital Transformation strategy.
• About the sponsor:
– Saint-Gobain Building Distribution is the company that bring together a number of
suppliers & brands that supply material & tools into the construction industry
– The company is part of the wider Saint-Gobain Group & uses IT infrastructure that is both
within UK datacentres & IT services headquartered in France.
– Saint Gobain employ over 180,000 people and are present in 68 countries.
• Useful links:
– https://www.saint-gobain.com/en

4. Integrating Design with Development
RAML

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RAML Integrating Design with Development
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• RAML for Console
– Requires to root element to be valid
and ideally have all code in the
specification to render the console
– Requires that securitySchemes defined
and a securedBy element populated by
at least null to provide console
functionality
– The documentation element allows a
readme file to be included in the
console that can give instructions for
expected behavior and information in
the described resource

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RAML Integrating Design with Development
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• RAML for Anypoint Exchange
– Requires the title element to create
the maven artefact name
– Requires the version to populate the
main version grouping of the
published Anypoint Exchange
artefact
– The documentation element is
incorporated within the Anypoint
Exchange artefact and can be cut
and pasted into the artefact page
– baseUri and resource methods auto-
populate in an artefact description
pane, together with instance
information

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RAML Integrating Design with Development
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• RAML for API Manager
– The title element is taken from
the title in Anypoint Exchange
which is populated from the
original element
– version required to differentiate
API implementation and produce
unique autodiscovery string
– baseUri required to populate the
location of the API
implementation

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RAML Integrating Design with Development
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• RAML for Anypoint Studio
– Flows can be generated with payload
stubs using the imported RAML
specification

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RAML Integrating Design with Development
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• RAML for Anypoint Studio
– The first parts of a RAML
definition can be used to provide
configuration details to
developer
– Prevents typing errors and
assigns correct testing details
– item definitions aid with using
‘as :String’ or
Integer.parseInt(message.inbou
ndProperties.ID) functions when
declaring values

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RAML Integrating Design with Development
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• RAML for Anypoint Studio
– Examples data can be included
initially to aid with setting output
payloads
– Object definitions can be used to
provide meta-data for
transformations
– Objects can be used as input into
query-parms expressions
– It is easier to carry out null
checking on json objects than to
remember to so this for each
query-param used in a HTTP
requester

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RAML Integrating Design with Development
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• Useful Resources
– There are a number of books that can
help learn API design and RAML
particularly – Manning: The Design of
Web APIs & Undisturbed REST
– API Workbench is a package that can
be installed into ATOM editor
– Design Centre at Anypoint Platform
– The RAML Specification – GitHub
project
– The resources at RAML Org
– The API Design Course from Mulesoft
Training

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RAML Integrating Design with Development
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Demo Time
• Anypoint Design Centre
– This RAML project describes the
access of objects from a collection
and shows how the RAML
develops to describe the objects
contained and how they can be
searched
– My main recommendation being
that rather than specifying
queryParams, that objects
describe instead what can be
searched via the queryString
element

13. Networking time
Introduce yourself to your neighbours!

14. The Power of Transformation
- Venkata Nallapuneni (Ven): Integration Developer for Rathbones
Brothers PLC
DataWeave 2.0

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Background and Overview
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• DataWeave language is introduced in Mule 4.0
• Replaces Mule Expression Language (MEL)
• Supported by Anypoint Studio version 7 onwards
• Features
– New functions/methods are added
– Improved power and method of transformation
– Simplified syntaxes
– Accessibility
– Ease of Learning
– Use of Data weave reduced the need for multiple transformers
– Process flow are more simplified compared to Mule 3 versions

16. “There’s nothing in this universe that can’t be
explained. Eventually.”
House MD

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Understanding Capabilities
Transformation and Functions
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• Many transformers are deprecated in Mule 4.0, as data weave replaces type
transformations
• Functions can be defined in any way as required
• Operators are now functions
• Simplified transformation using data weave
• Transforms complex data and binary data can also be extracted from an expression
• Type coercion errors are reduced comparatively
• DataWeave language can be used in most components like http request, file
connector, database etc.

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Use Dataweave expression in Variable
Transformation and Functions
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Transforms type and we can also define data type within same component

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File Connector and use of DataWeave language
1. - Use any Type of DW expression
in the components like file
connector, database, http request
etc.
2. - Write or read mime types as
needed.
• Eg:
write(payload,”application/xml”)
• - DataWeave expressions not
limited to content, can also be used
in path .
• - Coding Language type expressions
• if and else
•

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Accessing parameters is simplified in DataWeave 2
Simplifications and Inbound Properties
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• Inbound properties are changed to attributes and outbound properties are removed
• Eg:
attributes.headers.id instead of message.inboundproperties.id
attributes.queryParams.company (camel casing for all attributes)
• Variables can be easily accessed in data weave 2.0 –replaced as variable (session
vars and record vars are removed)
• Access these parameters in any component that supports data weave expression

21. DataWeave Modules and types
2.0

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DataWeave types 2.0
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Dataweave types are improved in every
version, have powerful capabilities
• dw::Core
Functions such as : camelize,capitalize etc.
• dw::Crypto
• dw::Runtime
• dw::core::Strings
• dw::core::URL
• dw::core::Binaries
• Etc.. Ex: stream a pdf document
• Create your own custom modules

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What's New
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New Data Formats Introduced
• Avro (application/avro)
• ndjson (application/x-ndjson)
• Java Properties (text/x-java-properties)
• Joins and improved functionalities in each dataweave types
Ex: Right Join, Inner Join and Left join can be used within dataweave
• Data types are improved in every module

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Conclusion
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Useful Links and Resources:
• https://docs.mulesoft.com/mule-runtime/4.1/dataweave
• https://help.mulesoft.com/s/forum
• https://docs.mulesoft.com/mule-runtime/4.2/dataweave-cookbook
Blogs:
• https://blogs.mulesoft.com/dev/mule-dev/dataweave-2-2-arrays-part1/

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Ven
Mulesoft Developer

26. See you next time
Please send topic suggestions to the organizer