Question

我有一个使用Thymeleaf的Spring Boot 1.3应用程序。我有一个屏幕，显示用户列表，包括他们与之关联的机构。感谢之前的一些StackOverflow帮助，我可以创建一个新用户并从下拉列表中选择他们的机构。我现在正在尝试为编辑用户做类似的事情 - 当您编辑记录时，下拉默认为用户已被分配的机构。

我有一个用户：

@Entity
@Table(name = "Users")
public class User implements UserDetails {

    @Id
    private String username;
    ...
    @ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinColumn(name = "institutionId", nullable = false)
    private Institution institution;
}

和一个机构：

@Entity
@Table(name = "Institution")
public class Institution {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long institutionId;
    private String name;

    @OneToMany(mappedBy = "institution", fetch = FetchType.EAGER)
    @Fetch(value = FetchMode.SUBSELECT)
    List<User> users = new ArrayList<User>();
}

这是我的HTML编辑用户记录（已编辑）：

我附加了屏幕截图，显示有指定机构的用户，但是当我尝试编辑时，没有下拉列表。

如何获得该下拉菜单，并且最好使用user.institution预先选择？

在这里，您可以看到编辑用户没有下拉列表：

编辑以显示进度并清理问题：我有它，以便当我去编辑时，列表会显示给用户的机构。

<div class="col-md-5">
    <div th:if="${user.institution != null }"
        <select name="user.institution">
            <option th:each="choice : ${institutionList}"
                    th:value="${choice.institutionId}"
                    th:attr="choiceinstitutionId=${choice.institutionId}, institutioninstitutionId=*{institution.institutionId}, showselected=(${choice.institutionId} == *{institution.institutionId})"
                    th:selected="(${choice.institutionId} == *{institution.institutionId})"
                    th:readonly="(${choice.institutionId} == *{institution.institutionId})"
                th:text="${choice.name}">
            </option>
        </select>
    </div>
    <div th:if="${user.institution == null }">
        <div th:if="${institutionList != null and not #lists.isEmpty(institutionList)}">
            <select name="user.institution">
                    <option th:each="dropDownItem : ${institutionList}"
                            th:value="${dropDownItem.institutionId}"
                            th:text="${dropDownItem.name}" />
            </select>
        </div>
        <div th:if="${institutionList == null or #lists.isEmpty(institutionList)}">
            <div>"No Institutions were found, please create some first"</div>
        </div>
    </div>

    <div th:if="${institutionList == null or #lists.isEmpty(institutionList)}">
        <div>"No Institutions were found, please create some first"</div>
    </div>
</div>

这非常接近，除了它实际上没有在用户对象上设置选定的下拉值，因此每次都设置为null ...

Answer 1

原来这是一个愚蠢的错误 - 实际上没有声明要设置的字段。如果其他人遇到类似的问题，这里有正确的代码来显示列表中的任何选定值，并设置它：

 <div th:if="${user.institution != null }">
    <select name="user.institution" th:field="*{institution}">
        <option th:each="choice : ${institutionList}"
                th:value="${choice.institutionId}"
                th:attr="choiceinstitutionId=${choice.institutionId}, institutioninstitutionId=*{institution.institutionId}, showselected=(${choice.institutionId} == *{institution.institutionId})"
                th:selected="(${choice.institutionId} == *{institution.institutionId})"
                th:readonly="(${choice.institutionId} == *{institution.institutionId})"
                th:text="${choice.name}"></option>
    </select>
</div>
<div th:if="${user.institution == null }">
    <div th:if="${institutionList != null and not #lists.isEmpty(institutionList)}">
        <select name="user.institution" th:field="*{institution}">
            <option th:each="dropDownItem : ${institutionList}"
                    th:value="${dropDownItem.institutionId}"
                    th:text="${dropDownItem.name}" />
        </select>
    </div>
    <div th:if="${institutionList == null or #lists.isEmpty(institutionList)}">
        <div>"No Institutions were found, please create some first"</div>
    </div>
</div>

百里香叶显示从对象中选择的值

1 个答案: