# Business Logic — FUW00943SF02DBean.removeElementFromListData() [13 LOC]

| Field | Value |
|-------|-------|
| Fully Qualified Name | `eo.web.webview.FUW00943SF.FUW00943SF02DBean` |
| Layer | Service / Web View Bean (Controller-facing data transfer object) |
| Module | `FUW00943SF` (Package: `eo.web.webview.FUW00943SF`) |

## 1. Role

### FUW00943SF02DBean.removeElementFromListData()

This method performs **dynamic list item removal** within the web view bean's data model, specifically for managing survey/registration answer lists in a service contract change (Futsu Iin = regular account transfer) scenario. It acts as a **parametric list manipulation utility** that routes removal requests based on the key name, allowing screen controllers to remove individual items from the `enquete_answer_list_list` (the "アンケート回答リスト" / Survey Answer List) at a specific index. The method implements a **defensive key-matching pattern**: it validates the key against a hardcoded Japanese string literal before performing any operation, and it bounds-checks the index to prevent out-of-range list access. This is a shared utility method embedded in the view bean (DBean), called by parent beans (e.g., `FUW00943SFBean`) which delegate to it, making it a cross-screen component available to multiple FUW00943SF sub-screens.

## 2. Processing Pattern (Detailed Business Logic)

```mermaid
flowchart TD
    START(["removeElementFromListData(key, index)"])

    START --> COND_NULL["key != null?"]

    COND_NULL -->|No| END_RETURN(["Return (no-op)"])

    COND_NULL -->|Yes| COND_KEY["key.equals(\"アンケート回答リスト\")?"]

    COND_KEY -->|No| END_RETURN

    COND_KEY -->|Yes| COND_INDEX["0 <= index < enquete_answer_list_list.size()?"]

    COND_INDEX -->|No| END_RETURN

    COND_INDEX -->|Yes| REMOVE["enquete_answer_list_list.remove(index)"]

    REMOVE --> END_RETURN
```

**Processing flow:**

1. **Null guard**: Validates that `key` is not `null`. If `key` is `null`, the method returns immediately as a no-op.
2. **Key routing**: Checks whether `key` equals the Japanese string `"アンケート回答リスト"` (Survey Answer List). Only matching keys proceed; all other keys are silently ignored.
3. **Index bounds check**: Validates that `index` is within the current size of `enquete_answer_list_list` (inclusive of 0, exclusive of size). If out of bounds, returns without modification.
4. **Element removal**: Removes the element at the specified `index` from `enquete_answer_list_list`, shifting subsequent elements left.

## 3. Parameter Analysis

| No | Parameter Name | Type | Business Description |
|----|---------------|------|---------------------|
| 1 | `key` | `String` | The item name used to identify which list should be modified. In this method, it must match `"アンケート回答リスト"` (Survey Answer List) to trigger removal. This is the label used by the web view to bind the parameter to the correct domain entity. |
| 2 | `index` | `int` | The zero-based position of the list item to remove from the survey answer list. Must be within `[0, size)` to have any effect. |

**Instance fields read:**

| Field | Type | Business Description |
|-------|------|---------------------|
| `enquete_answer_list_list` | `X33VDataTypeList` | The survey answer list — a structured data container holding answer items for the service contract change enrollment questionnaire. Each element is an `X33VDataTypeBeanInterface` object representing a single answer entry. |

## 4. CRUD Operations / Called Services

This method performs an **in-memory list mutation** with no external service component (SC) calls, CBS calls, or database interactions.

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| U | `enquete_answer_list_list.remove(index)` | — | — (in-memory `X33VDataTypeList`) | Removes a survey answer item from the client-side list data at the specified index, shifting subsequent elements left. This is a local data model update, not a persistence operation. |

## 5. Dependency Trace

| # | Caller (Screen/Batch) | Call Chain (Full Path to this Method) | Terminal (SC / CRUD / Entity) |
|---|----------------------|--------------------------------------|-------------------------------|
| 1 | Screen: `FUW00943SF` | `FUW00943SFBean.removeElementFromListData(key, index)` -> `super.removeElementFromListData(key, index)` -> `FUW00943SF02DBean.removeElementFromListData` | `enquete_answer_list_list.remove(index) [U] (in-memory)` |

**Notes on callers:**

- `FUW00943SFBean` (line 2282–2288) overrides `removeElementFromListData` and delegates to `super.removeElementFromListData(key, index)`, which dispatches to `FUW00943SF02DBean.removeElementFromListData()`.
- The method is a **leaf utility** with no further downstream SC/CBS/database calls.
- No other FUW00943SF sub-screens or batches invoke this method directly.

## 6. Per-Branch Detail Blocks

**Block 1** — IF `(key != null)` (L692)

> Null guard: If `key` is `null`, skip all processing and return.

| # | Type | Code |
|---|------|------|
| 1 | SET | (no-op; method returns immediately if key is null) |

**Block 2** — IF `(key.equals("アンケート回答リスト"))` (L695)

> Key routing: Checks if the key matches the survey answer list identifier. `"アンケート回答リスト"` translates to "Survey Answer List" — the Japanese label used by the web view to identify the enrollment questionnaire answer list entity.

| # | Type | Code |
|---|------|------|
| 1 | EXEC | `key.equals("アンケート回答リスト")` // "Survey Answer List" — key match guard |

**Block 2.1** — IF `(index >= 0 && index < enquete_answer_list_list.size())` (L696)

> Bounds check: Validates the index is within the current list size. If valid, removes the element. Comment (in Japanese): "指定のインデックスが現在のリストの範囲内にあれば、そのインデックスの内容を削除する" (If the specified index is within the current list range, delete the content at that index).

| # | Type | Code |
|---|------|------|
| 1 | EXEC | `index >= 0` // lower bound check |
| 2 | EXEC | `index < enquete_answer_list_list.size()` // upper bound check (exclusive) |
| 3 | CALL | `enquete_answer_list_list.remove(index)` // Removes element at index, shifts remaining elements left |

## 7. Glossary

| Term | Type | Business Meaning |
|------|------|------------------|
| `enquete_answer_list_list` | Field | Survey Answer List — an `X33VDataTypeList` holding answer entries for the service contract change enrollment questionnaire. Each entry is a structured data bean. |
| `enquete` | Abbreviation | Survey / Questionnaire — short for "enquete" (investigation/survey), referring to the customer enrollment questionnaire data. |
| `"アンケート回答リスト"` | Field (Japanese) | "Survey Answer List" — the Japanese label used as a key to identify the survey answer list in the view bean's data routing logic. |
| `FUW00943SF` | Module | Futsu Iin (Regular Account Transfer) — a service change screen module for regular service contract line item transfers in K-Opticom's telecom billing system. |
| DBean | Abbreviation | Data Bean — a view bean (`X33VViewBaseBean` implementor) that holds UI-bound data for a specific screen sub-page. |
| `X33VDataTypeList` | Type | A framework-provided list container in the X33 view framework, implementing `X33VDataTypeBeanInterface` for type-safe data binding between view components and Java objects. |
| `X33SException` | Type | X33 Service Exception — the runtime exception type used by the X33 web framework for service-layer error propagation. |
| Futsu Iin | Business term | Regular Account Transfer / Service Contract Line Item Transfer — a telecom service change operation where a customer transfers their existing service contract to another line or account. |