Aleksey Stukalov (Haulmont) CUBA Platform approach to development of highly customizable software products CUBA Platform - A high level open source Java framework for enterprise applications https://www.cuba-platform.com/.

1. By Aleksey Stukalov
How to Develop Highly
Customizable Off-the-Shelf
Software

2. Off-the-Shelf vs Custom Software
Off-the-Shelf
• Generic
• Customization is laborious or impossible
Custom
• 100% designed for the individual customer
• Difficult to productize for new customers

3. Ideal Product
• Implements “good for all” - common business features
• Also implements “good only for me” - distinctive business features
for individual client
• Customization does not impede regular core product updates

4. Adjust Model
Product Customization

5. Modify Business Logic

6. Adjust UI

7. Widely Used Techniques
• All in One
• Branching
• Entity-Attribute-Value
• Plugins

8. All in One: Concept
• Keep single codebase
• Employ ‘feature toggling’

9. All in One: Customizability
• Database Layer
• Business Logic Layer
• User Interface Layer

10. All in One: Ideal Scenario
• Established, mostly static business area
• Limited customization requirements
• Inability to deliver custom development does not impact sales

11. All in One: What if the assumptions
were wrong
• Customer is unhappy due to lack of desired features
OR
• Codebase turns into the unmanageable garbage can

12. Branching: Concept
• Create a new branch for the customer
• Customize whatever is needed in isolation

13. Branching: Customizability
• Database Layer
• Business Logic Layer
• User Interface Layer

14. Branching: Ideal Scenario
• Master branch is mature and does not require rapid delivery of
new features
• Only a few customer branches required
• Customer branches do not require frequent synchronization with
the core product branch

15. Branching: What if the
assumptions were wrong
Constant merging from master to branches and vice versa:
• Becomes extremely time consuming
• Leads to unavoidable regression bugs

16. EAV: Concept
• Deliver “as is”
• Employ a mechanism to dynamically add custom fields to entities
on-the-fly
• Mix with other techniques to enable Business Logic customization

17. EAV: Customizability
• Database Layer
• User Interface Layer*
* UI can be customized to some extent and naturally limited by the
pre-programmed display logic

18. EAV: Ideal Scenario
• Flexibility of having additional informative data is required
• Additional data is not explicitly used in the product business logic

19. EAV: Limitations
• Cannot be applied for Business Logic customization
• May add complications to data utilization and increases the
database load

20. Plugins: Concept
• Define ‘Points of Customization’ (aka Extension points)
• Develop functional logic in separate (isolated) artefacts (plugins or
scripts)
• Dynamically execute attached plugins in the pre-defined
Customization Points

21. Plugins: Customizability
• Database Layer
• Business Logic Layer
• User Interface Layer

22. Plugins: Ideal Scenario
• Points of Customization are easy to predict
• User Interface modifications are quite trivial
• Business Logic modifications to be added only in Points of
Customization, not in between

23. Plugins: Limitations
• Any layer can be customized to some extent, which is naturally
limited by ‘Points of Customization’
• Architecture becomes more complicated
• ‘Just in case’ scattering of ‘Customization Points’ leads to poor code
readability and hard debug

24. Ideal Framework Requirements
• Customization from Model to UI
• Clear separation between underlying Product and On-Top
Customizations
• Possibility of tight interlacement of Customization and Product
functionality
• Entire product to be opened for customization

25. CUBA Extensions
• Implemented in the CUBA platform – a high level framework for
enterprise software development
• Based on the Open Inheritance pattern
Main Principles
• Inherit all the features of an underlying product, using it as a library
• Contain only distinctive features, without copying untouched
product functionality
• Support hierarchical customization model

26. Model Customization: Challenge
• Product implements User entity
• Customer requires address and department fields to be added
• Department is required to be a separate entity, linked to a User

27. Model Customization:
Implementation

28. Model Customization: @Extends
• Base entity use should be substituted globally across the product:
– Constructors
– JPQL queries
– Model traversal

29. Model Customization:
How it works
• Object Factory always returns the deepest child using metadata
model
• All JPQL queries are parsed, analyzed and modified according to
the metadata model
• Model traversal substitution is reached by orm.xml generation,
where target-entity attribute refers to the deepest child

30. Product CUBA extension
UI Customization: How it works

31. UI Customization: Product Screen

32. UI Customization: Extension Screen

33. Spring framework does it – no
need to reinvent what already
exists!
• Declare a @Component
• Override in the extension
• Re-register the new class in
the extension
• The new implementation will
be used across the whole
product
Business Logic Customization

34. Updating the Underlying
Product Version
• Specify the new version of the underlying product in extension
• Meet product API changes in the overlapped parts
• Rebuild the product with the extension

35. Hierarchical Customization Model

36. Summary

37. Based on mainstream technologies
Implements:
• CUBA Extensions
• Scripting
• Entity-Attribute-Value
CUBA Platform

38. Our Experience: Thesis
Enterprise Content Management system
• Over 200 implementations
• 26 custom solutions based on the product
Delivery of 26 projects to huge customers would not be possible
without deep system customization

39. Our Experience:
Sherlock Taxi Solution
Complete Taxi Management Solution
• 12 implementations
• 7 custom solutions based the product
• 2 ongoing customizations
Product is constantly being updated for all customers bringing new
product features.

40. Hands-on Labs
Try CUBA extensions at our Hands-on Labs, with the help of our CUBA
experts, you will develop a fully-functioned business application in
just a couple of hours
When: Wednesday 28th October 2015
Where: Hilton-Franciscan Room A
Lab 1: 10:00 am - 12:00 pm
Lab 2: 12:30 pm - 2:30 pm
Lab 3: 3:00 pm - 5:00 pm

41. By Aleksey Stukalov
Thank you!