Primefaces 选项列表。 DualListModel 的设置器删除源和目标

Question

我的选择列表有问题。显示源和目标有效，但是当按下命令按钮时，它会调用选择列表的设置器并清空选择列表的源和目标。之后它调用方法connectTags()。

这种行为的原因是什么，我该如何解决？

<h:form>
    <p:pickList id="pickList" value="#{employeeEditController.dualListTags}"
        var="tag" itemLabel="#{tag.value}" itemValue="#{tag}">
        <f:facet name="sourceCaption">Available</f:facet>
        <f:facet name="targetCaption">Connected</f:facet>  
    </p:pickList>
    <p:commandButton value="Save" actionListener="#{employeeEditController.connectTag()}"/>
</h:form>

豆子：

@Named(value = "employeeEditController")
@SessionScoped
public class EmployeeEditController implements Serializable, IEditController {
    private Employee selectedEmployee;
    private DualListModel<Tags> dualListTags;

@Inject
private EmployeeFacade employeeFacade;
@Inject
private CompanyFacade companyFacade;
@Inject
private TagFacade tagFacade;

public void setSelectedEmployee(Employee selectedEmployee) {
    System.out.println("setSelectedEmployee called. Value: " + selectedEmployee.getFirstName());
    this.selectedEmployee = selectedEmployee;
    this.refreshDualList();
}

private void refreshDualList(){
    List<Tags> source = (List<Tags>) this.getCompanyTags();
    List<Tags> target = (List<Tags>) this.getTags();
    System.out.println("refreshDualList called. \nSource: " + source.size() +
            "Target: " + target.size());
    this.dualListTags = new DualListModel<Tags>(source, target);
}

public Collection<Tags> getTags(){
    Collection<Tags> retVal;
    if(this.selectedEmployee != null){
        retVal = this.selectedEmployee.getTags();
        if(retVal == null){
           retVal = new ArrayList<Tags>();
        } 
    } else{
        System.out.println("selected emp is null");
        retVal = new ArrayList<Tags>();
    }
    return retVal;
}

public Collection<Tags> getCompanyTags() {
    Collection<Tags> retVal = new ArrayList<Tags>();
    if(this.companyID == null){
        String userstr = FacesContext.getCurrentInstance().getExternalContext().getRemoteUser();
        this.companyID = this.companyFacade.getCompanyIDByUser(userstr);
    }
    retVal = this.tagFacade.getTagsFromCompanyID(companyID);
    return retVal;
}

public void save(){
    if(this.selectedEmployee != null){
        System.out.println("Save called. Value: " + this.selectedEmployee.getFirstName());
        this.employeeFacade.edit(this.selectedEmployee);
    }
}

public void connectTag() {
    if(this.dualListTags != null){
        System.out.println("connectTag() called.\n" + "source: " + this.dualListTags.getSource().size() + 
                "\ntarget: " + this.dualListTags.getTarget().size());
        this.selectedEmployee.setTags((Collection<Tags>)this.dualListTags.getTarget());
        this.save();
    }
}

public DualListModel<Tags> getDualListTags() {
    System.out.println("getDualList called. \nSource :" + this.dualListTags.getSource().size()
            + "\nTargets: " + this.dualListTags.getTarget().size());
    return this.dualListTags; 
}

public void setDualListTags(DualListModel<Tags> dualListTags) {
    System.out.println("setDualList called. \nSource :" + this.dualListTags.getSource().size()
            + "\nTargets: " + this.dualListTags.getTarget().size());
    this.dualListTags = dualListTags;
    System.out.println("setDualList called after set. \nSource :" + this.dualListTags.getSource().size()
                + "\nTargets: " + this.dualListTags.getTarget().size());
    }

}

Answer 1

我遇到了同样的问题，似乎解决方案是为您在选择列表中使用的实体实施自定义转换器。

这是我的自定义转换器的样子：

@ViewScoped
@ManagedBean(name = "vehicleGroupConverter")
public class VehicleGroupConverter implements Converter {

    @ManagedProperty(value = "#{vehiclesBean}")
    private VehiclesBean vehiclesBean;

    @Override
    public Object getAsObject(FacesContext context, UIComponent component,
            String value) {
        long groupId = Long.parseLong(value);
        List<AssetCategory> groups = vehiclesBean.getVehicleGroups();
        for (AssetCategory group : groups) {
            if (group.getCategoryId() == groupId) {
                return group;
            }
        }
        return null;
    }

    @Override
    public String getAsString(FacesContext context, UIComponent component,
            Object value) {
        return Long.toString(((AssetCategory) value).getCategoryId());
    }

    public void setVehiclesBean(VehiclesBean vehiclesBean) {
        this.vehiclesBean = vehiclesBean;
    }

}

这是选择列表模板部分：

<p:pickList id="vehicleGroups" 
        value="#{vehiclesBean.selectedVehicleGroups}" 
        var="group" 
        itemLabel="#{group.name}" 
        itemValue="#{group}"
        converter="#{vehicleGroupConverter}"
        styleClass="pf-panel-grid"
        style="margin-bottom:10px">
    <f:facet name="sourceCaption">#{i18n['label-available-groups']}</f:facet>
    <f:facet name="targetCaption">#{i18n['label-assigned-groups']}</f:facet>
</p:pickList>

Answer 2

当源或目标不为空时设置duallistmodel：

public void setDualListTags(DualListModel<Tags> dualListTags) {
    if(this.dualListTags.getSource().size()!=0 && this.dualListTags.getTarget().size()!=0) {
        this.dualListTags = dualListTags;
    }
}