---
source_files:
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/Utilities/DiskUtility.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/Utilities/Exceptional.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/Utilities/ExceptionalList.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/Utilities/AttributeCoder.cs
generated_at: "2026-04-17T15:53:59.285477+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "c2a6300146b5dc97"
---

# Documentation: DatabaseExport Utilities

## 1. Purpose

This module provides utility classes for the `DatabaseExport` subsystem within the DataPRO Version 57 codebase. It includes an exception-handling base class hierarchy (`Exceptional`, `ExceptionalList<T>`) designed to enable type-specific exception catching, a disk/file validation utility (`DiskUtility`), and a reflection-based attribute manipulation framework (`AttributeCoder<TargetType, AttributeType, AttributeValueType>`) for encoding/decoding attribute values attached to types—primarily intended for use with enumeration types.

---

## 2. Public Interface

### `Exceptional` (abstract class)
**Namespace:** `DatabaseExport`  
**Inheritance:** `object` ← `Exceptional`  
**Attributes:** `[Serializable]`

An abstract marker/base class with no members. Intended as the "ultimate" base class for classes that expect to throw exceptions, allowing callers to catch exceptions by the throwing class's type.

---

### `ExceptionalList<T>` (generic class)
**Namespace:** `DatabaseExport`  
**Inheritance:** `List<T>` ← `ExceptionalList<T>`  
**Attributes:** `[global::System.Serializable]`

A generic collection that inherits from `List<T>` and is intended to provide its own exception type. No additional members are defined beyond those inherited from `List<T>`.

---

### `DiskUtility` (static class)
**Namespace:** `DatabaseExport`  
**Inheritance:** `Exceptional` ← `DiskUtility`

A collection of disk-related utility methods.

#### Methods

| Signature | Description |
|-----------|-------------|
| `public static bool ValidateFileAndPathNameChars(string nameToValidate)` | Validates that the input string contains no illegal file or path characters. Returns `true` if valid, `false` otherwise. |

**Validation rules applied:**
- Rejects strings that are empty or whitespace-only after trimming
- Rejects strings containing any character from `Path.GetInvalidFileNameChars()`
- Rejects strings containing any character from `Path.GetInvalidPathChars()`
- Rejects strings containing the period character (`'.'`)

---

### `AttributeCoder<TargetType, AttributeType, AttributeValueType>` (generic class)
**Namespace:** `DatabaseExport`  
**Inheritance:** `Exceptional` ← `AttributeCoder<,,>`

A reflection-based utility for manipulating attributes attached to types, designed primarily for enum-to-attribute value mapping.

#### Delegates

| Delegate | Signature |
|----------|-----------|
| `AttributeValueExtractionMethod` | `AttributeValueType(AttributeType attribute)` |
| `AttributeValueEqualityComparisonMethod` | `bool(AttributeValueType value1, AttributeValueType value2)` |

#### Constructor

```csharp
public AttributeCoder(
    AttributeValueExtractionMethod attributeValueExtractionMethod,
    AttributeValueEqualityComparisonMethod attributeValueEqualityComparisonMethod)
```

Initializes the coder with a required extraction method and an optional equality comparison method. If `attributeValueEqualityComparisonMethod` is `null`, default equality comparison is used.

#### Methods

| Signature | Description |
|-----------|-------------|
| `public AttributeValueType DecodeAttributeValue(TargetType target)` | Returns the attribute value of `AttributeType` attached to the specified `TargetType`. Expects exactly one attribute; throws if none found. |
| `public List<AttributeValueType> DecodeAttributeValues(TargetType target)` | Returns a list of all `AttributeValueType` values from `AttributeType` attributes attached to the specified `TargetType`. |
| `public TargetType EncodeAttributeValue(AttributeValueType attributeValue)` | Returns the `TargetType` value that has an `AttributeType` attribute with the specified value. Expects exactly one match; throws otherwise. |
| `public List<TargetType> DehashAttributeValue(AttributeValueType attributeValue)` | Returns