在向下钻取SelectOneMenus（Parent-Child）中显示值 [英] Display values in drill-down SelectOneMenus (Parent-Child)

问题描述

当我填充两个 selectOneMenu 的深入选择时，我有恼人的问题。第一个菜单是扇区，它控制另一个 Categorty 。我根据扇区加载了类别的选择，所有这些工作正常。

I have irritating problem when I populate a drill-down selection of two selectOneMenu. The first menu is Sector which controls the other one Categorty. I load the selection for the Category depending on Sector and all of this is working fine.

但是当我编辑一个具有类别（有一个）扇区的业务对象时它。首次加载 edit.xhtml 页面时，不会显示类别。我知道 SessionScoped 支持bean中的值是正确的。如果我选择另一个扇区类别然后返回到初始扇区，那么类别得到正确设置就会保留在第一个位置。

But when I edit a business object that has a Category (has one) Sector attached to it. The Category doesn't get display when first loading the edit.xhtml page. I know the value is correct in the SessionScoped backing bean. If I select another Sector-Category and then go back to the initial Sector, the Category get properly set at it was persisted in the first place.

POJO类（扇区） -Category）具有 hashCode（）和 equals（对象对象）函数。

The POJO classes (Sector-Category) has the hashCode() and equals(Object object) functions.

我为POJO对象生成了CRUD生成的JSF转换器，但我不认为这会导致问题。我认为第二个 selectOneMenu 由于某种原因不会显示其值。如果我将父（Sector）翻转到其他东西并返回初始状态，则显示来自manged bean的正确值。

I have CRUD generated JSF converters for the POJO object, but I don't think this is causing the problem. I think the second selectOneMenu don't display its value as it should for some reason. If I flip the parent (Sector) to something else and the back to the initial state, the correct value from the manged bean get displayed.

我可以制作类别 selectOneMenu 组件显示托管bean中的值？

Ho can I make the Category selectOneMenu component display the value in the managed bean?

问候Chris

面临错误消息

FacesMessage(s) have been enqueued, but may not have been displayed.
sourceId=null[severity=(ERROR 2), summary=(No activity selected), detail=(No activity selected)]

Edit.xhtml

Edit.xhtml

... 
<h:outputLabel value="Sector:" />                    
<h:selectOneMenu id="sectorSelector" value="#{activityController.selectedSector}" title="#{bundle.CreateSectorLabel_sectorName}" required="false" requiredMessage="#{bundle.CreateSectorRequiredMessage_sectorName}"
        valueChangeListener="#{activityController.changeSectorMenu}"
            disabled="#{activityController.activityStatusOngoing or activityController.activityStatusComplete}">
    <f:ajax event="change" execute="@this" render="categoryMenu"/>
            <f:selectItems value="#{sectorController.itemsAvailableSelectOne}"/>
</h:selectOneMenu>

<h:outputLabel value="Category:" />
    <h:selectOneMenu id="categoryMenu" value="#{activityController.selectedCategory}" title="#{bundle.CreateSectorLabel_sectorName}" 
        required="true" requiredMessage="#{bundle.CreateCategoryRequiredMessage_sector}"
            disabled="#{activityController.activityStatusOngoing}" rendered="true"> 
    <f:selectItems value="#{activityController.categorySelection}"/>
    </h:selectOneMenu>
...

类别的控制器bean

Controller bean for Category

@ManagedBean(name = "categoryController")
@SessionScoped
public class CategoryController implements Serializable{

    ....

    @FacesConverter(forClass = Category.class)
    public static class CategoryControllerConverter implements Converter {

        @Override
        public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
            if (value == null || value.length() == 0) {
                return null;
            }
            CategoryController controller = (CategoryController) facesContext.getApplication().getELResolver().
                    getValue(facesContext.getELContext(), null, "categoryController");
            return controller.ejbFacade.find(getKey(value));
        }

        java.lang.Integer getKey(String value) {
            java.lang.Integer key;
            key = Integer.valueOf(value);
            return key;
        }

        String getStringKey(java.lang.Integer value) {
            StringBuffer sb = new StringBuffer();
            sb.append(value);
            return sb.toString();
        }

        @Override
        public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
            if (object == null) {
                return null;
            }
            if (object instanceof Category) {
                Category o = (Category) object;
                return getStringKey(o.getIdCategory());
            }
            else {
                throw new IllegalArgumentException("object " + object + " is of type " + object.getClass().getName() + "; expected type: " + CategoryController.class.getName());
            }
        }
    }

POJO对象的一部分

Part of POJO object

...
public class Category implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "idCategory")
    private Integer idCategory;
    ...

推荐答案

这不是我首先想到的是转换器。这是两个 selectOneMenu 的渲染。这是我对xhml文件所做的更改。感谢您的时间和精力，问候Chris。

It was not the Converters as I first thought. It was the rendering of the two selectOneMenu. This is the changes I did to the xhml file. Thank you for your time and effort, greetings Chris.

Edit.xhml

Edit.xhml

<h:outputLabel value="Sector:" />                    
<h:selectOneMenu id="sectorSelector" value="#{activityController.selectedSector}" title="#{bundle.CreateSectorLabel_sectorName}" required="false" requiredMessage="#{bundle.CreateSectorRequiredMessage_sectorName}"
        valueChangeListener="#{activityController.changeSectorMenu}" immediate="true"
            disabled="#{activityController.activityStatusOngoing or activityController.activityStatusComplete}">
    <a4j:ajax event="change" execute="@this categoryMenu" render="categoryMenu"/>
            <f:selectItems value="#{sectorController.itemsAvailableSelectOne}"/>
</h:selectOneMenu>

<h:outputLabel value="Category:" />
    <h:selectOneMenu id="categoryMenu" value="#{activityController.selectedCategory}" title="#{bundle.CreateSectorLabel_sectorName}" 
        binding="#{activityController.categoryMenu}"
            required="true" requiredMessage="#{bundle.CreateCategoryRequiredMessage_sector}"                                     
            disabled="#{activityController.activityStatusOngoing}">
            <f:selectItems value="#{activityController.categorySelection}"/>
</h:selectOneMenu>

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