bootstrap-selectで1つだけ選択できるプルダウンリストを作る方法

# HTMLの`select`とJavaScriptで作る場合
- 環境
    - jquery 1.9.1
    - bootstrap 3.3.7
    - bootstrap-select 1.12.4

## 1. 普通の1つだけ選択できるセレクトボックスを作る
![Screen Shot 2017-09-22 at 0.54.46.png](https://qiita-image-store.s3.amazonaws.com/0/159761/061380f0-4201-731c-5b32-069d344b40bd.png)![Screen Shot 2017-09-22 at 1.00.56.png](https://qiita-image-store.s3.amazonaws.com/0/159761/66126caa-255f-04ea-ff85-771ac706b239.png)

```html
<!DOCTYPE html>
<html>
<head>
    <title>bootstrap-selctで作るプルダウン</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
    <script type="text/javascript" src="js/myBootstrapSelect.js"></script>
</head>
<body>
    <select id="targetSelect" size="1"></select>
</body>
</html>
```

```js:myBootstrapSelect.js
var selectOptionCount = 3;

$(window).on('load', function() {
    createSelectOption();
});

function createSelectOption() {
    var selectObj = $('#targetSelect');

    for (var i = 0; i < selectOptionCount; i++) {
        var option = $('<option>');
        option.html(i);
        selectObj.append(option);
    }
}
```
```html:出力されるHTML(ある程度整形済)
<!--省略-->
<body>
    <select id="targetSelect" size="1">
        <option>0</option>
        <option>1</option>
        <option>2</option>
    </select>
</body>
</html>
```

## 2. `bootstrap.min.css`と`bootstrap-select.min.css`と`bootstrap.min.js`を読み込む
```html
<!-- 省略 : 変更なし -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.12.4/css/bootstrap-select.min.css">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
    <script type="text/javascript" src="js/myBootstrapSelect.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.12.4/js/bootstrap-select.min.js"></script>
<!-- 省略 : 変更なし -->
```

## 3. `<select>`の`class`に`selectpicker`を指定する
```html
<!-- 省略 : 変更なし -->
    <select id="targetSelect" size="1" class="selectpicker"></select>
<!-- 省略 : 変更なし -->
```

## 4. 完成:hatched_chick:
![Screen Shot 2017-09-23 at 16.41.06.png](https://qiita-image-store.s3.amazonaws.com/0/159761/000dad37-0b64-b481-56ab-81992206bf0e.png)

```html:出力されるHTML(ある程度整形済)
<!--省略-->
    <div class="btn-group bootstrap-select open">
        <button type="button" class="btn dropdown-toggle btn-default" data-toggle="dropdown" role="button" data-id="targetSelect" title="0" aria-expanded="true">
            <span class="filter-option pull-left">0</span>
            &nbsp;
            <span class="bs-caret">
                <span class="caret"></span>
            </span>
        </button>
        <div class="dropdown-menu open" role="combobox" style="max-height: 530px; overflow: hidden; min-height: 0px;">
            <ul class="dropdown-menu inner" role="listbox" aria-expanded="true" style="max-height: 518px; overflow-y: auto; min-height: 0px;">
                <li data-original-index="0" class="selected">
                    <a tabindex="0" class="" data-tokens="null" role="option" aria-disabled="false" aria-selected="true">
                        <span class="text">0</span>
                        <span class="glyphicon glyphicon-ok check-mark"></span>
                    </a>
                </li>
                <li data-original-index="1">
                    <a tabindex="0" class="" data-tokens="null" role="option" aria-disabled="false" aria-selected="false">
                        <span class="text">1</span>
                        <span class="glyphicon glyphicon-ok check-mark"></span>
                    </a>
                </li>
                <li data-original-index="2">
                    <a tabindex="0" class="" data-tokens="null" role="option" aria-disabled="false" aria-selected="false">
                        <span class="text">2</span>
                        <span class="glyphicon glyphicon-ok check-mark"></span>
                    </a>
                </li>
            </ul>
        </div>
        <select id="targetSelect" size="1" class="selectpicker" tabindex="-98">
            <option>0</option>
            <option>1</option>
            <option>2</option>
        </select>
    </div>
</body>
</html>
```

# JSFの`h:selectOneMenu`とJavaScriptで作る場合
- 環境
    - CentOS Linux release 7.8.2003 (Core)
    - openjdk version "11.0.7" 2020-04-14 LTS
    - JSF 2.3.9
    - jquery 3.2.1
    - bootstrap 4.3.1
    - bootstrap-select 1.13.14

```xml
<!--省略-->
<h:head>
  <title>ponsukeのQiita用</title>
  <!-- bootstrapとbootstrap-selectのJsとCssを読み込む -->
  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" />
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-select@1.13.14/dist/css/bootstrap-select.min.css" />
  <script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
  <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
  <script src="https://cdn.jsdelivr.net/npm/bootstrap-select@1.13.14/dist/js/bootstrap-select.min.js"></script>
</h:head>
<h:body>
  <h:form id="formId">
    <h:panelGroup>
      <!-- classにはselectpickerを指定する. -->
      <h:selectOneMenu id="select" styleClass="selectpicker" value="#{sampleBean.selected}">
        <f:selectItems value="#{sampleBean.selectItems}" />
      </h:selectOneMenu>
    </h:panelGroup>
  </h:form>
<!--省略-->
```

```java:SampleBean.java
// 省略
import javax.annotation.PostConstruct;
import javax.faces.model.SelectItem;
import javax.faces.view.ViewScoped;
import javax.inject.Named;

import lombok.Getter;
import lombok.Setter;

@Named
@ViewScoped
public class SampleBean implements Serializable {
// 省略
    /** セレクトボックスの選択肢. */
    @Getter
    private List<SelectItem> selectItems;
    /** セレクトボックスで選択した値. */
    @Getter
    @Setter
    private Integer selected;

    /** Beanの初期化処理. */
    @PostConstruct
    public void init() {
        setSelectItems();
    }

    /** 選択肢を設定する. */
    private void setSelectItems() {
        selectItems = new ArrayList<SelectItem>();
        selectItems.add(new SelectItem(0, "   "));
        selectItems.add(new SelectItem(1, "いぬ"));
        selectItems.add(new SelectItem(2, "ねこ"));
        selectItems.add(new SelectItem(3, "さる"));
        selectItems.add(new SelectItem(4, "ぽんすけ"));
    }
}
```

![a.gif](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/159761/17a9318e-1730-f258-1382-c43564d05257.gif)

```html:出力されるHTML(ある程度整形済)
<!--省略-->
<div class="dropdown bootstrap-select">
  <select id="formId:select" name="formId:select" class="selectpicker" size="1" tabindex="-98">
    <option value="0"></option>
    <option value="1">いぬ</option>
    <option value="2">ねこ</option>
    <option value="3">さる</option>
    <option value="4">ぽんすけ</option>
  </select>
  <button type="button" class="btn dropdown-toggle btn-light" data-toggle="dropdown" role="combobox" aria-owns="bs-select-1" aria-haspopup="listbox" aria-expanded="false" data-id="formId:select" title="Nothing selected">
    <div class="filter-option">
      <div class="filter-option-inner">
        <div class="filter-option-inner-inner">Nothing selected</div>
      </div>
    </div>
  </button>
  <div class="dropdown-menu" x-placement="bottom-start" style="max-height: 955px; overflow: hidden; min-height: 104px; position: absolute; will-change: transform; top: 0px; left: 0px; transform: translate3d(5px, 35px, 0px);">
    <div class="inner show" role="listbox" id="bs-select-1" tabindex="-1" aria-activedescendant="bs-select-1-0" style="max-height: 939px; overflow-y: auto; min-height: 88px;">
      <ul class="dropdown-menu inner show" role="presentation" style="margin-top: 0px; margin-bottom: 0px;">
        <li class="selected active">
          <a role="option" class="dropdown-item active selected" id="bs-select-1-0" tabindex="0" aria-setsize="5" aria-posinset="1" aria-selected="true">
            <span class="text">   </span>
          </a>
        </li>
        <li class="">
          <a role="option" class="dropdown-item" id="bs-select-1-1" tabindex="0" aria-setsize="5" aria-posinset="2">
            <span class="text">いぬ</span>
          </a>
        </li>
        <li>
          <a role="option" class="dropdown-item" id="bs-select-1-2" tabindex="0" aria-setsize="5" aria-posinset="3">
            <span class="text">ねこ</span>
          </a>
        </li>
        <li>
          <a role="option" class="dropdown-item" id="bs-select-1-3" tabindex="0" aria-setsize="5" aria-posinset="4">
            <span class="text">さる</span>
          </a>
        </li>
        <li class="selected active">
          <a role="option" class="dropdown-item active selected" id="bs-select-1-4" tabindex="0" aria-setsize="5" aria-posinset="5" aria-selected="true">
            <span class="text">ぽんすけ</span>
          </a>
        </li>
      </ul>
    </div>
  </div>
</div>
<!--省略-->
```