Another Look at App Integration in Business Central – Part 2
This post demonstrates how to integrate two independent Business Central apps without creating a direct dependency between them by using interfaces and a shared app integration layer. The approach allows apps to register and discover each other's functionality at runtime using enums, dictionaries, and version management.
post James Pearson
"The challenge that we are trying to solve is to allow Business Central apps to call each other's functionality without creating a dependency."
Key points
- Apps can integrate without direct dependencies by implementing interfaces defined in a shared app integration layer
- An App Integration codeunit uses a dictionary to store and manage implementations of interfaces from different apps
- Version numbers in interface names enable future contract changes while preventing breaking changes
- Consuming apps check for interface implementation before calling external app functionality, with fallback logic if unavailable
- The pattern separates concerns with each app owning specific responsibilities through single responsibility principle
Quotes
- “The challenge that we are trying to solve is to allow Business Central apps to call each other’s functionality without creating a dependency.” (This defines the core problem the solution addresses - enabling optional app integration without tight coupling)
- “Each app should have a clear set of responsibilities which does not overlap with the responsibilities of another app.” (Explains the architectural principle driving the design - separation of concerns ensures maintainability and independent deployment)
AL objects mentioned
As named in the post. A name that matches one object page by exact type and name links to it; the others stay as named.
- interface “IShippingAgentIntegration1.0”
- interface “IApp”
- enum “App”
- codeunit “App Integration”
- codeunit “Shipping Agent Integration”
- codeunit “Calc. Shipping Charges”
Not found in BC28-30: interface “IShippingAgentIntegration1.0”, interface “IApp”, enum “App”, codeunit “App Integration”, codeunit “Shipping Agent Integration”, codeunit “Calc. Shipping Charges”.
Context
- Features: Interface-based app integration, Runtime implementation registration, Version management for interfaces, Dictionary-based implementation storage, Implementation discovery and casting, Event-based initialization, Fallback logic for missing implementations
Source: James Pearson, community blog. Summary, key points and quotes are derived (CONTENT-NOTICE.md); read the original for the full text.