java - 下拉列表中的 JSF 树

Question

我想在 JSF 的下拉列表中显示树状结构。基本上，选择的项目处于层次结构中，我希望它在下拉列表中很明显。

这可能吗？

Answer 1

所以，您基本上想要一个 HTML <optgroup> ？使用 SelectItemGroup .

JSF bean(我假设是 JSF 1.x):

private String option; // +getter +setter
private List<SelectItem> options; // +getter

public Bean() {
    options = new ArrayList<SelectItem>();

    SelectItemGroup group1 = new SelectItemGroup("Group 1");
    group1.setSelectItems(new SelectItem[] {
        new SelectItem("Group 1 Value 1", "Group 1 Label 1"),
        new SelectItem("Group 1 Value 2", "Group 1 Label 2"),
        new SelectItem("Group 1 Value 3", "Group 1 Label 3")
    });
    options.add(group1);

    SelectItemGroup group2 = new SelectItemGroup("Group 2");
    group2.setSelectItems(new SelectItem[] {
        new SelectItem("Group 2 Value 1", "Group 2 Label 1"),
        new SelectItem("Group 2 Value 2", "Group 2 Label 2"),
        new SelectItem("Group 2 Value 3", "Group 2 Label 3")
    });
    options.add(group2);
}

JSF View :

<h:selectOneMenu value="#{bean.option}">
    <f:selectItems value="#{bean.options}" />
</h:selectOneMenu>

生成的 HTML 示例:

<select name="j_idt6:j_idt7" size="1">
    <optgroup label="Group 1">
        <option value="Group 1 Value 1">Group 1 Label 1</option>
        <option value="Group 1 Value 2">Group 1 Label 2</option>
        <option value="Group 1 Value 3">Group 1 Label 3</option>
    </optgroup>
    <optgroup label="Group 2">
        <option value="Group 2 Value 1">Group 2 Label 1</option>
        <option value="Group 2 Value 2">Group 2 Label 2</option>
        <option value="Group 2 Value 3">Group 2 Label 3</option>
    </optgroup>
</select>

它在浏览器中的样子: