Developers: architecture

This section is for developers who build on Media Bridge from their own extension, or who need to understand how it works inside. Media Bridge targets Business Central 28.0 (runtime 17.1) and is SaaS-first.

All objects use the FRW affix and live in the namespace TheFramework.MediaBridge, with these sub-namespaces:

Namespace	Contents
TheFramework.MediaBridge.Storage	Storage interfaces, providers, the FRW Media Storage Mgt facade, the shared drop control
TheFramework.MediaBridge.Setup	Setup table and page, Manual Setup registration, permission sets
TheFramework.MediaBridge.Migration	Migration engine, runs and log, wizard, clear utilities
TheFramework.MediaBridge.Inventory	Item and Item Variant adapters, pages and the Item Carousel
TheFramework.MediaBridge.HumanResources	Employee adapter and pages

Two extensible enums, two interfaces

flowchart TD
    P[Pages and event subscribers] --> F[codeunit FRW Media Storage Mgt]
    F --> S[[enum FRW Media Storage Source<br/>implements FRW IMediaStorageProvider]]
    F --> E[[enum FRW Media Entity<br/>implements FRW IMediaEntity]]
    S --> T[FRW Tenant Media Provider]
    S --> X[FRW Ext. Storage Provider]
    X --> O[FRW IExternalFileOps<br/>External File Storage module]
    E --> I[FRW Item Media Entity]
    E --> V[FRW Item Var. Media Entity]
    E --> M[FRW Employee Media Entity]
    E --> U[FRW Unknown Media Entity<br/>default: raises an error]

Where a picture is stored : enum "FRW Media Storage Source" (Extensible = true) implements interface "FRW IMediaStorageProvider": TenantMedia → FRW Tenant Media Provider, ExternalFileStorage → FRW Ext. Storage Provider.

Which record a picture belongs to : enum "FRW Media Entity" (Extensible = true) implements interface "FRW IMediaEntity": Item, ItemVariant, Employee. The default and unknown-value implementation is FRW Unknown Media Entity, which raises an error, so a value without an adapter never silently acts as another entity.

One entry point : codeunit "FRW Media Storage Mgt" is the only object pages and subscribers call. It resolves the active provider from setup and handles consumer mode (media source company).

Design rules

• Providers don't modify business records. UploadPicture returns the file path and timestamp; the caller writes them to the record with SetExtFileReference. DeletePicture removes bytes; the caller clears the reference. This keeps database writes out of [TryFunction]s.
• Tenant Media writes can't be try-wrapped. Media.ImportStream inserts the Tenant Media row at once. Batch callers use FRW Media Record Writer through a conditional Codeunit.Run, which rolls back only the failing record.
• Read errors carry a reason. A failed read raises inside the provider's try, so GetLastErrorText() names the real cause.
• One MIME map. MIME type ↔ file extension mapping lives only in FRW Media Storage Mgt.
• Control add-ins are asynchronous. Every AL → JavaScript call waits for OnControlReady, JavaScript never returns values, and add-in references are never kept in single-instance codeunits. Each add-in is wrapped behind an interface (FRW IItemCarousel, FRW IPictureDropControl) so the logic can be tested with a mock.

What's in this section

• Public API: the procedures of FRW Media Storage Mgt you can call from your extension.
• Extension points: adding a storage provider or a media entity, and the current limits.
• Telemetry: the telemetry events Media Bridge emits.