116 lines
7.6 KiB
Markdown
116 lines
7.6 KiB
Markdown
---
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source_files:
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- DataPRO/Modules/SystemSettings/Tables/ViewModel/TablesSettingsViewModel.cs
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generated_at: "2026-04-16T04:40:21.830816+00:00"
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model: "Qwen/Qwen3-Coder-Next-FP8"
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schema_version: 1
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sha256: "d6165d55cd0ea9cd"
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---
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# ViewModel
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## Documentation: `TablesSettingsViewModel`
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---
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### 1. **Purpose**
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`TablesSettingsViewModel` is the view model for the *Tables Settings* module within the application’s UI layer. It acts as the data context for `ITablesSettingsView`, coordinating UI state (e.g., busy status, menu/navigation visibility) and bridging communication between the view and the application’s event infrastructure via `IEventAggregator`. It also exposes `InteractionRequest`s to support modal notifications and confirmations through Prism’s interaction patterns. This module is part of a modular, MEF-exported component system and is intended to be shared across the application lifecycle.
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---
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### 2. **Public Interface**
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#### **Class: `TablesSettingsViewModel`**
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- **Exported as:** `[Export(typeof(ITablesSettingsView))]` — implies it is intended to be resolved as an `ITablesSettingsView` (likely via MEF or Unity).
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- **Creation Policy:** `Shared` — only one instance exists per application lifetime.
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##### **Properties**
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| Property | Type | Description |
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|---------|------|-------------|
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| `View` | `ITablesSettingsView` | Reference to the associated view; set in constructor. |
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| `NotificationRequest` | `InteractionRequest<Notification>` | Used to trigger display of notification popups (e.g., informational messages). |
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| `ConfirmationRequest` | `InteractionRequest<Confirmation>` | Used to trigger confirmation dialogs. |
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| `IsDirty` | `bool` | Read-only; currently always `false` (no logic implemented to set it). |
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| `IsBusy` | `bool` | Gets/sets busy state; raises `PropertyChanged` on change. |
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| `IsMenuIncluded` | `bool` | Gets/sets whether the menu is included in the view; raises `PropertyChanged`. |
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| `IsNavigationIncluded` | `bool` | Gets/sets whether navigation is included in the view; raises `PropertyChanged`. |
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| `HeaderInfo` | `string` | Read-only; always returns `"MainRegion"`. |
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##### **Methods**
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| Method | Signature | Description |
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|--------|-----------|-------------|
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| `Cleanup` | `void Cleanup()` | No-op stub. |
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| `CleanupAsync` | `Task CleanupAsync()` | Returns `Task.CompletedTask`. |
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| `Initialize` | `void Initialize()` | No-op stub. |
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| `Initialize` | `void Initialize(object parameter)` | No-op stub. |
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| `Initialize` | `void Initialize(object parameter, object model)` | No-op stub. |
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| `InitializeAsync` | `Task InitializeAsync()` | Returns `Task.CompletedTask`. |
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| `InitializeAsync` | `Task InitializeAsync(object parameter)` | Returns `Task.CompletedTask`. |
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| `Activated` | `void Activated()` | No-op stub. |
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##### **Event Handlers (Private)**
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| Method | Signature | Description |
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|--------|-----------|-------------|
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| `OnBusyIndicatorNotification` | `private void OnBusyIndicatorNotification(bool eventArg)` | Sets `IsBusy` to `eventArg`. |
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| `OnRaiseNotification` | `private void OnRaiseNotification(NotificationContentEventArgs eventArgsWithTitle)` | Transforms `NotificationContentEventArgs` (with title/message/image) into a `Notification` object and raises `NotificationRequest`. Note: it discards the `Title` and `Image` fields of the original event args and passes them via `NotificationContentEventArgs` constructor with empty strings for some parameters — see *Gotchas*. |
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##### **Interface Implementations**
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| Interface | Method | Signature | Description |
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|-----------|--------|-----------|-------------|
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| `INotifyPropertyChanged` | `PropertyChanged` | `event PropertyChangedEventHandler PropertyChanged` | Raised via `OnPropertyChanged`. |
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| `IBasePropertyChanged` | `OnPropertyChanged` | `void IBasePropertyChanged.OnPropertyChanged(string propertyName)` | Delegates to `OnPropertyChanged(propertyName)`. |
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| — | `SetProperty` | `bool SetProperty<T>(ref T storage, T value, string propertyName = null)` | **Throws `NotImplementedException`** — not implemented. |
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---
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### 3. **Invariants**
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- `View.DataContext` is always set to `this` (the view model) in the constructor.
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- `IsBusy` is initialized to `false` and only modified via `OnBusyIndicatorNotification`, which is subscribed to `BusyIndicatorChangeNotification`.
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- `NotificationRequest` and `ConfirmationRequest` are initialized in the constructor and never reassigned.
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- `HeaderInfo` is a constant string `"MainRegion"` and never changes.
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- `IsDirty` is declared but never set — its value remains `false` for the lifetime of the instance.
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- `SetProperty` is declared but unimplemented — calling it will always throw `NotImplementedException`.
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---
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### 4. **Dependencies**
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#### **Imports / Dependencies (via constructor parameters and `using` directives)**
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- **Prism Libraries**:
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- `IEventAggregator` — for pub/sub event handling.
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- `IRegionManager` — for region navigation (though unused in current implementation).
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- `Unity` container (`IUnityContainer`) — for dependency injection.
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- **Custom Infrastructure**:
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- `DTS.Common.Events.RaiseNotification` — event type subscribed to in constructor.
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- `DTS.Common.Events.BusyIndicatorChangeNotification` — event type subscribed to in constructor.
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- `DTS.Common.Base.IBasePropertyChanged` — interface implemented explicitly.
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- `DTS.Common.Interface.ITablesSettingsView` — view interface.
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- **MEF**:
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- `[Export(typeof(ITablesSettingsView))]` — indicates this type is registered as an export for `ITablesSettingsView`.
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- **UI Framework**:
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- `Prism.Regions`, `Prism.Events`, `Prism.Interactivity` — used for region management, event aggregation, and interaction requests.
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#### **Depended Upon By**
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- The view (`ITablesSettingsView`) — this view model is bound to its `DataContext`.
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- Likely consumed via MEF/Unity resolution as `ITablesSettingsView`.
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- Other modules may publish `RaiseNotification` or `BusyIndicatorChangeNotification` events to trigger UI feedback via this view model.
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---
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### 5. **Gotchas**
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- **`SetProperty` is unimplemented** — throws `NotImplementedException`. This breaks expected MVVM patterns (e.g., `INotifyPropertyChanged` helpers). Developers should avoid calling it.
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- **`NotificationContentEventArgs` transformation in `OnRaiseNotification` is lossy**:
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The method constructs a new `NotificationContentEventArgs` with empty strings for the 2nd and 4th parameters (likely `OkContent` and `CancelContent`), discarding any original values. This may cause unexpected behavior if callers expect those fields to be preserved.
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- **No-op lifecycle methods**: `Initialize`, `InitializeAsync`, `Activated`, `Cleanup`, and `CleanupAsync` contain no logic — may indicate incomplete implementation or deferred functionality.
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- **`IsDirty` is never set**: Despite being a public property, it is never assigned — always `false`. This may mislead consumers expecting dirty-state tracking.
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- **`HeaderInfo` is hardcoded**: Always returns `"MainRegion"` — no dynamic behavior or configuration.
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- **`IBasePropertyChanged.OnPropertyChanged` is implemented explicitly** — only callable via interface cast.
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- **Thread context for `BusyIndicatorChangeNotification`**: Subscribed with `ThreadOption.PublisherThread`, meaning the handler runs on the publisher’s thread — may require dispatcher marshaling if the publisher is not on the UI thread (though `IsBusy` setter calls `OnPropertyChanged`, which *should* marshal to UI thread if `INotifyPropertyChanged` is handled by Prism’s binding system).
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---
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*Documentation generated from source file `TablesSettingsViewModel.cs` only. No external behavior or assumptions beyond what is visible in the source.* |