uno-mvux-messaging

# MVUX Messaging — Agent Skill ## Workflow > **Docs lookup:** call `uno_platform_docs_search(...)` first, then `uno_platform_docs_fetch(sourcePath="…")` using the `sourcePath` field from a result (a relative `.md` path; add the result's `anchor` for a section). Never pass a URL, a `.html` link, or a hand-built path. ### Step 1: Fetch the Messaging Documentation Search for and fetch the messaging documentation: ``` uno_platform_docs_search("MVUX messaging EntityMessage synchronization CRUD") ``` Primary documentation pages: - **Messaging Reference**: `external/uno.extensions/doc/Learn/Mvux/Advanced/Messaging.md` - **Messaging How-To**: `external/uno.extensions/doc/Learn/Mvux/Walkthrough/Messaging.howto.md` Fetch the reference page: ``` uno_platform_docs_fetch(sourcePath="external/uno.extensions/doc/Learn/Mvux/Advanced/Messaging.md") ``` ### Step 2: For How-To Walkthroughs For step-by-step implementation: ``` uno_platform_docs_fetch(sourcePath="external/uno.extensions/doc/Learn/Mvux/Walkthrough/Messaging.howto.md") ``` This covers when to use messaging, sending entity messages from services, observing changes in models, and manual message handling. ### Step 3: Understand the Architecture From the fetched docs, the messaging pattern involves: 1. **Service** sends `EntityMessage<T>` via `IMessenger.Send(...)` 2. **Model** uses `.Observe(messenger)` on a `ListState` to auto-apply changes 3. **Entity changes** (Created/Updated/Deleted) are applied to the matching state ### Step 4: For Manual Message Handling If the user needs custom logic when messages arrive, the reference page covers the `Update` extension methods that allow manual application of `EntityMessage<T>` to states. ## Key Principles (Stable) - Register `IMessenger` as a singleton in DI: `services.AddSingleton<IMessenger, WeakReferenceMessenger>()` - `EntityMessage<T>` carries an entity change type (Created, Updated, Deleted) and the entity - `.Observe(messenger)` on a `ListState` auto-applies incoming entity changes - Records need key equality for matching (see `uno-mvux-records` skill) - Namespace: `Uno.Extensions.Reactive.Messaging` ## Related Skills - [[uno-mvux-liststate]] — Mutable collections that messaging updates - [[uno-mvux-records]] — Key equality for entity matching - [[uno-mvux-commands]] — Commands that trigger CRUD operations