---
source_files:
  - Common/DTS.Common/Interface/DTS.Viewer/TestModification/ITestModificationView.cs
  - Common/DTS.Common/Interface/DTS.Viewer/TestModification/ITestModificationViewModel.cs
  - Common/DTS.Common/Interface/DTS.Viewer/TestModification/ITestModificationModel.cs
generated_at: "2026-04-16T03:07:00.161504+00:00"
model: "Qwen/Qwen3-Coder-Next-FP8"
schema_version: 1
sha256: "43122e167ffc47f8"
---

# TestModification

### **Purpose**  
This module defines the core interfaces for the *Test Modification* feature within the DTS Viewer application, enabling users to inspect and modify channel-specific calibration and configuration parameters (e.g., description, Eu multiplier/offset, T0/T1/T2 line-fit settings, sensitivity, software filters, and data flags). It implements the MVVM pattern across three layers—`ITestModificationView` (UI), `ITestModificationViewModel` (presentation logic), and `ITestModificationModel` (data/access to calibration and channel state)—to support interactive editing of test channel metadata and calibration values, including integration with the sensor database for calibration updates.

---

### **Public Interface**  

#### **`ITestModificationView`**  
- **Inherits**: `IBaseView`  
- **Description**: A marker interface representing the view layer for the test modification UI. No additional members beyond base view contract.

#### **`ITestModificationViewModel`**  
- **Inherits**: `IBaseViewModel`  
- **Properties**:  
  - `ITestModificationView View { get; set; }` — Binds to the associated view instance.  
  - `IBaseViewModel Parent { get; set; }` — Reference to the parent view model (e.g., main viewer or channel list).  
  - `bool UseISOCodeFilterMapping { get; set; }` — Controls whether modifying a software filter should trigger automatic ISO code updates.  
  - `bool UseZeroForUnfiltered { get; set; }` — Determines whether `0` (vs. `P`) is used as the ISO code value when the software filter is set to "unfiltered".  
- **Methods**:  
  - `void PublishChanges()` — Commits pending modifications (likely to the model or underlying data layer).  
  - `void UpdateDatabaseMethod()` — Updates the sensor calibration record in the database (see [case 43615](http://manuscript.dts.local/f/cases/43615/SW-Feature-Request-UART-Channel-Diagnostics-GPS-NMEA-1PPS)).  

#### **`ITestModificationModel`**  
- **Inherits**: `IBaseModel`  
- **Properties**:  
  - `ITestModificationViewModel Parent { get; set; }` — Reference to the owning view model.  
  - `ITestChannel SelectedChannel { get; set; }` — The channel currently being modified.  
  - `string Description { get; set; }` — Channel description string; `IsModifiedDescription` tracks changes.  
  - `double EuMultiplier { get; set; }` — Eu multiplier; `IsModifiedEuMultiplier` tracks changes.  
  - `double EuOffset { get; set; }` — Eu offset; `IsModifiedEuOffset` tracks changes.  
  - `double T0 { get; set; }` — T0 offset in ms; `IsModifiedT0` tracks changes.  
  - `bool IsModifiedLineFit { get; set; }` — Whether T1/T2 line-fit parameters are modified.  
  - `double T1 { get; set; }` — Line-fit start time (ms).  
  - `double T2 { get; set; }` — Line-fit end time (ms).  
  - `double Sensitivity { get; set; }` — Channel sensitivity; `IsModifiedSensitivity` tracks changes.  
  - `IFilterClass SelectedFilter { get; set; }` — Software filter for the channel (per [FB 13120](https://github.com/...), uses `IFilterClass` instead of legacy `CFCFilter`).  
  - `T0Mode T0Mode { get; set; }` — T0 adjustment mode (enum value; type defined elsewhere).  
  - `DataFlag SelectedDataFlag { get; set; }` — Data flag setting; `IsModifiedDataFlag` tracks changes.  
  - `ISensorDbRecord Sensor { get; set; }` — Sensor record in the database corresponding to the channel.  
  - `ISensorCalDbRecord Cal { get; set; }` — Latest calibration record for the sensor.  
  - `double CalSensitivity { get; set; }` — Sensitivity value from the calibration record.  
  - `bool ShowSensorCal { get; }` — Whether sensor calibration UI should be visible.  
  - `bool NonLinear { get; }` — Whether the calibration is non-linear.  
  - `bool ProportionalToExcitation { get; }` — Whether the sensor output is proportional to excitation voltage.  
- **Computed Flags** (read-only):  
  - `bool IsModified { get; }` — `true` if *any* field differs from its default/unmodified state.  
  - `bool IsModifiedDescription { get; }`  
  - `bool IsModifiedEuMultiplier { get; }`  
  - `bool IsModifiedEuOffset { get; }`  
  - `bool IsModifiedT0 { get; }`  
  - `bool IsModifiedSensitivity { get; }`  
  - `bool IsModifiedFilter { get; }`  
  - `bool IsModifiedDataFlag { get; }`  
- **Methods**:  
  - `bool ValidateT0()` — Returns `true` if `T0` is within the valid time range of the current dataset; `false` otherwise.  

---

### **Invariants**  
- `SelectedChannel` must be non-null for all model properties to be meaningful; behavior is undefined if `SelectedChannel` is `null`.  
- `IsModified*` flags are derived from comparisons against default/unmodified values and must be consistent with the corresponding property values.  
- `ValidateT0()` must return `false` if `T0` falls outside the time span of the dataset associated with `SelectedChannel`.  
- `CalSensitivity`, `NonLinear`, `ProportionalToExcitation`, and `ShowSensorCal` are derived from the `Cal` and `Sensor` records and must reflect their current state.  
- `SelectedFilter` must be assignable to `IFilterClass` (no direct dependency on legacy `CFCFilter` per comment).  
- `UseISOCodeFilterMapping` and `UseZeroForUnfiltered` control ISO code behavior *only when* a software filter is modified; they do not affect other fields.  

---

### **Dependencies**  
- **Internal Dependencies**:  
  - `DTS.Common.Base` — Provides `IBaseView`, `IBaseViewModel`, `IBaseModel`.  
  - `DTS.Common.Interface.Sensors` — Provides `ISensorDbRecord`, `ISensorCalDbRecord`.  
  - `DTS.Common.Interface.Sensors.SoftwareFilters` — Provides `IFilterClass`.  
  - `ITestChannel` — Referenced but not defined in these files; assumed to be defined elsewhere in `DTS.Common.Interface`.  
  - `T0Mode` — Enum type referenced but not defined here.  
  - `DataFlag` — Enum type referenced but not defined here.  
- **Depended Upon By**:  
  - Concrete implementations of `ITestModificationView`, `ITestModificationViewModel`, and `ITestModificationModel` (e.g., WPF views, view models, and data models in the viewer module).  
  - Likely consumed by higher-level modules managing test channel editing workflows (e.g., main viewer, channel list, or calibration manager).  

---

### **Gotchas**  
- `IsModifiedLineFit` is the *only* `bool` property in `ITestModificationModel` with a public setter (`set`); all other `IsModified*` properties are read-only. This may indicate that line-fit modification state can be externally forced (e.g., reset), but usage is unclear without implementation context.  
- `UpdateDatabaseMethod()` lacks parameterization; it likely operates on the current `SelectedChannel`, `Sensor`, and `Cal` state. Side effects (e.g., DB write, validation) are not documented beyond the XML comment.  
- `UseZeroForUnfiltered` and `UseISOCodeFilterMapping` are *not* validated or enforced in the interface—behavior depends on implementation.  
- No explicit error handling or exception contracts are defined (e.g., for `PublishChanges()` or `UpdateDatabaseMethod()`).  
- `ValidateT0()`’s validity criteria ("within the dataset") are underspecified: dataset bounds are not defined in the interface.  
- None of the `IsModified*` flags are resettable via the interface—implementation may require external reset (e.g., after `PublishChanges()`).  
- None identified from source alone.