# ClassModules Knowledge Base

**Scope:** `VBA/ClassModules/` - Domain logic classes

## OVERVIEW

4 classes: `ProductModelParser` (parse model strings), `BomItem` (data model), `ConditionEvaluator` (evaluate conditions), `BomExtractor` (core matching logic).

## STRUCTURE

```
ClassModules/
├── ProductModelParser.cls   # Parse model strings → extract 6 conditions
├── BomItem.cls              # BOM data model (11 fields)
├── ConditionEvaluator.cls   # Evaluate condition expressions
└── BomExtractor.cls         # Core matching + assembly logic
```

## WHERE TO LOOK

| Task | Location | Notes |
|------|----------|-------|
| Parse model string | `ProductModelParser.cls` | `Parse()` method |
| Extract conditions | `ProductModelParser.cls` | Returns `azxs`, `bkxs`, `gclj`, `jycz`, `lcfw`, `fjgn` |
| Load BOM row | `BomItem.cls` | `LoadFromRow()` with type conversion |
| Evaluate condition | `ConditionEvaluator.cls` | `Evaluate(condition, conditions)` |
| Match BOM items | `BomExtractor.cls` | `ExtractBom()` with 4-step process |
| Assembly logic | `BomExtractor.cls` | `ApplyAssemblyLogic()` parent/child override |

## CODE MAP

### ProductModelParser
| Method | Role |
|--------|------|
| `Parse(modelString)` | Entry point, validates format |
| `ParseHeader()` | Splits model string by `-` and `.` |
| `ExtractConnectionAndMaterial()` | Separates `gclj` and `jycz` from code |
| `ExtractAdditionalFeatures()` | Removes oil-fill type (Y+digit) from `fjgn` |

### BomItem
| Property | Type | Column |
|----------|------|--------|
| `RowNumber` | Long | A |
| `Module` | String | B |
| `code` | String | C |
| `Name` | String | D |
| `quantity` | Double | E |
| `SelectCondition` | String | F |
| `Remark` | String | G |
| `category` | String | H |
| `ParentCategory` | String | I |
| `CategoryCondition` | String | J |
| `Code66` | String | K |

### BomExtractor
| Method | Role |
|--------|------|
| `LoadBomData()` | Loads from row 4 (header row 3) |
| `ExtractBom(conditions)` | 4-step: determine categories → match → apply assembly → validate |
| `ApplyAssemblyLogic()` | Parent overrides children if all match |
| `ValidateResult()` |双向覆盖检查 (parent/child coverage) |

## CONVENTIONS

### Class Structure
```vba
Option Explicit

' Private state
Private pPropertyName As Type

' Initialize
Private Sub Class_Initialize()
    Set pProperty = New Collection
End Sub

' Public methods
Public Function MethodName() As ReturnType
    On Error GoTo ErrorHandler
    ' Logic
    Exit Function
ErrorHandler:
    ' Handle
End Function
```

### Condition Dictionary
All condition methods accept `Scripting.Dictionary` with keys: `azxs`, `bkxs`, `gclj`, `jycz`, `lcfw`, `fjgn`.

### Error Collection Pattern
```vba
Private pErrorMessages As Collection
Public Function GetErrorSummary() As String
    ' Join all errors with "; "
End Function
```

## ANTI-PATTERNS (THIS PROJECT)

- **NEVER** change `BomItem.LoadFromRow()` column indices — hardcoded to match platform configuration sheet
- **NEVER** remove `On Error Resume Next` in `LoadFromRow()` — type conversions fail gracefully
- **NEVER** skip validation in `ValidateResult()` —双向覆盖检查 prevents false negatives
- **DO NOT** modify `BomExtractor.LoadBomData()` row start — must be row 4 (row 3 is header)

## UNIQUE STYLES

### Assembly Logic Algorithm
```vba
' 1. Build parent→child map from CategoryHierarchy
' 2. Count matches per category
' 3. If parent=1 AND all children≥1 → parent covers children
' 4. Output parent only, hide children
```

### Model String Format
```
[Header]-[Spec1].[Spec2].[Spec3].[Spec4].[Spec5]|[Detail1]|[Detail2]
Example: Y-100-M203.316SS.L100.N2

Parsed conditions:
- azxs (安装形式): M (vertical)
- bkxs (表壳形式): 3
- gclj (过程连接): M20
- jycz (接液材质): 3 (316SS)
- lcfw (量程范围): 0.L100
- fjgn (附加功能): N2 (from .316SS.L100.N2)
```

### Condition Expression Syntax
```vba
' Single: "field=value"
' OR: "field1=value1|field2=value2"
' Example: "azxs=M|azxs=L" → vertical OR horizontal
```

## NOTES

### Category Hierarchy
Built from `ParentCategory` field (column I). Example:
- "接头" → "部件"
- "弹性元件" → "部件"
- Result: if "部件" matches AND both children match → output "部件" only

### Type Conversion
`BomItem.LoadFromRow()` uses `CLng()`, `CStr()`, `CDbl()` with `On Error Resume Next` — invalid conversions become 0 or empty string.

### Scripting.Dictionary
Windows-only. All dictionary usage via `CreateObject("Scripting.Dictionary")`.