# Business Logic — KKW21502SFChecker.checkMethod() [8 LOC]

| Field | Value |
|-------|-------|
| Fully Qualified Name | `eo.web.webview.KKW21502SF.KKW21502SFChecker` |
| Layer | Web WebView (Screen/Check Component) |
| Module | `KKW21502SF` (Package: `eo.web.webview.KKW21502SF`) |

## 1. Role

### KKW21502SFChecker.checkMethod()

This method serves as the primary check dispatch entry point (チェック処理の振分け) for the KKW21502SF (Contract Content Notification Document Detail Update / Statement) screen within the K-Opticom web application platform. It implements the `X31SGuiCheckBase.checkMethod` contract, which is part of the X31 framework's GUI check handler pattern. The method acts as a validation gate that is invoked by the X31 framework prior to processing a screen operation, allowing business-level checks to be executed before any database or service-level logic runs. As a no-op implementation, it currently always returns `true` (check passes normally), meaning no additional screen-specific validation rules are enforced beyond the standard framework checks. The method reserves the capability to set a result pattern ID via `param.setResultPatternID()` for multi-result scenarios, supporting future extensibility where different outcome categories could trigger distinct downstream behaviors. Its role in the larger system is that of a shared check component tied to the KKW21502 screen, called by the framework's screen processing pipeline whenever that screen performs a validated operation.

## 2. Processing Pattern (Detailed Business Logic)

```mermaid
flowchart TD
    START(["checkMethod(param, errMsgStock)"])
    STEP1["Extract patternID from param"]
    STEP2["Return true"]
    END_NODE(["Check passes: normal end"])

    START --> STEP1 --> STEP2 --> END_NODE
```

This method has no conditional branches, no service calls, and no CRUD operations. It extracts the `patternID` from the check parameter and immediately returns `true`, signaling that the check has passed successfully.

## 3. Parameter Analysis

| No | Parameter Name | Type | Business Description |
|----|---------------|------|---------------------|
| 1 | `param` | `X31SGuiCheckParam` | In/out check processing input parameter and framework instruction information. Carries the check result pattern ID (`patternID`) that can be used to identify the outcome category. The framework uses this object to communicate validation state and to return results back to the calling screen. For multi-result scenarios, the caller is expected to set the result pattern ID via `param.setResultPatternID()`. |
| 2 | `errMsgStock` | `X31GUtilStockMessage` | Out-only error message stock. Not used in normal operation; reserved for cases where special warnings or error messages need to be output at runtime. If utilized, the check bypasses its standard definition-based processing and returns only error message display. Currently unused in this implementation. |

**External state:**
- `this.bl` (`X31BBusinessLogic`) — The business logic class reference (specifically `KKW21502SFLogic`) injected via the constructor. Not accessed within `checkMethod` itself.

## 4. CRUD Operations / Called Services

This method performs no CRUD operations and calls no service components. The only operation is extracting a field from the input parameter and returning a boolean.

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| *(none)* | — | — | — | No service calls or database operations are performed in this method. |

## 5. Dependency Trace

| # | Caller (Screen/Batch) | Call Chain (Full Path to this Method) | Terminal (SC / CRUD / Entity) |
|---|----------------------|--------------------------------------|-------------------------------|
| 1 | Screen:KKW21502 (Contract Content Notification Document Detail Update / Statement) | Framework (`X31SGuiCheckBase`) -> `KKW21502SFChecker.checkMethod` | *(none)* |

**Notes on callers:**
- `KKW21502SFChecker` implements the `X31SGuiCheckBase` interface, meaning it is invoked by the X31 framework's screen processing pipeline. The specific entry point is the KKW21502 screen (Contract Content Notification Document / Statement), as defined in `JKKScreenConst.SCREEN_ID_KKW21502`.
- No direct Java callers were found referencing `KKW21502SFChecker.checkMethod` by name, as the invocation is framework-driven through the `X31SGuiCheckBase` interface contract.
- The KKW21502 screen is reachable as a next screen from KKW21501SF (Contract Content Notification Update), per the flow in `KKW21501SFLogic` which sets `SCREEN_ID_KKW21502` in the next screen data map.

## 6. Per-Branch Detail Blocks

**Block 1** — METHOD `(method body)` (L60)

> The method body executes linearly with no conditional branches or loops.

| # | Type | Code |
|---|------|------|
| 1 | SET | `String patternID = param.patternID;` // Extract the result pattern ID from the check parameter [-> patternID] |
| 2 | RETURN | `return true;` // Check passes normally — processing continues |

## 7. Glossary

| Term | Type | Business Meaning |
|------|------|------------------|
| `X31SGuiCheckBase` | Interface | X31 Framework GUI check base interface — defines the contract for screen-level validation components. Checkers implement this interface to plug into the framework's validation pipeline. |
| `X31SGuiCheckParam` | Class | X31 Framework check parameter object — carries input/output data between the calling screen and the checker, including the result pattern ID and framework instructions. |
| `X31GUtilStockMessage` | Class | X31 Framework error message stock utility — holds error/warning messages for display. Optional override mechanism for custom error output during checks. |
| `X31SException` | Class | X31 Framework business exception — thrown when a check or business process encounters a fatal error. |
| `X31BBusinessLogic` | Class | X31 Framework business logic base class — injected reference to the associated business logic class (`KKW21502SFLogic`). |
| KKW21502 | Screen ID | Contract Content Notification Document Detail Update / Statement (契約内容通知書詳細更新・照会) — the web screen this checker is associated with. |
| KKW21502SF | Service Feature | Contract Content Notification Document SF — the service feature (screen processing module) handling contract content notification document operations. |
| `patternID` | Field | Result pattern ID (結果パターンID) — identifies which result pattern/category the check execution belongs to. Used in multi-result scenarios via `param.setResultPatternID()`. |
| `bl` | Field | Business Logic reference — holds the reference to the KKW21502SFLogic class, injected via constructor for potential service-level operations. |
| X31 Framework | Technical | Fujitsu Futurity X31 web application framework — the underlying platform providing screen lifecycle management, data bean access, and check component invocation. |