Question

我有两个下拉菜单：一个是使用selectOneMenu组件实现的，另一个是使用selectCheckboxMenu实现的。

在selectOneMenu中选择一个选项时，selectCheckboxMenu的选项值会根据selectOneMenu中选择的选项进行更新。

发生以下情况：

我选择了selectOneMenu的一个选项，selectCheckboxMenu被填充
我选择/检查selectCheckboxMenu的一些选项
我选择selectOneMenu的另一个选项，selectCheckboxMenu会填充其他值
我选择了一些新值
我选择了selectOneMenu
不再选择我在步骤2中选择的值

我相信这是因为绑定到selectCheckboxMenu的列表值会被setter方法重置。

我想要的是全局保存selectCheckboxMenu的状态。这样做的最佳策略是什么？

编辑：

这里是复制先前行为的相关代码：

豆：

import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.inject.Inject;
import java.util.ArrayList;
import java.util.List;

@ManagedBean
@ViewScoped
public class BackingBean {

    private List<Parent> parents = new ArrayList<>();
    private List<Child> children = new ArrayList<>();
    private List<Child> selectedChildren = new ArrayList<>();
    private Parent selectedParent = new Parent();

    @Inject
    FamilyService service;

    @PostConstruct
    public void init(){
        parents = service.findParents();
    }


    public void parentChanged(){
        children = new ArrayList<>();
        if(getSelectedParent() == null){
            return;
        }

        children = service.findChildrenByParent(getSelectedParent());
    }

    public void selectedSonChanged(){
        System.out.println(selectedChildren.size());
    }

    public List<Parent> getParents() {
        return parents;
    }

    public void setParents(List<Parent> parents) {
        this.parents = parents;
    }

    public List<Child> getChildren() {
        return children;
    }

    public void setChildren(List<Child> children) {
        this.children = children;
    }

    public List<Child> getSelectedChildren() {
        return selectedChildren;
    }

    public void setSelectedChildren(List<Child> selectedChildren) {
        this.selectedChildren = selectedChildren;
    }

    public Parent getSelectedParent() {
        return selectedParent;
    }

    public void setSelectedParent(Parent selectedParent) {
        this.selectedParent = selectedParent;
    }
}

XHTML：

<html xmlns="http://www.w3.org/1999/xhtml"
        xmlns:f="http://java.sun.com/jsf/core"
        xmlns:h="http://java.sun.com/jsf/html"
        xmlns:p="http://primefaces.org/ui">
<h:head></h:head>
<h:body>
<h:form id="selectOne">
    <p:messages autoUpdate="true" />

        <h:outputLabel for="parents" value="Parents:" />
        <p:selectOneMenu converter="#{parentConverter}" id="parents" value="#{backingBean.selectedParent}">
            <p:ajax update="children" listener="#{backingBean.parentChanged}" />
            <f:selectItem noSelectionOption="true" value="#{null}" itemLabel="None" />
            <f:selectItems value="#{backingBean.parents}" var="p" itemLabel="#{p.name}" itemValue="#{p}" />
        </p:selectOneMenu>


        <h:outputLabel for="children" value="Children:" />

        <p:selectCheckboxMenu converter="#{childConverter}"  id="children"
                              value="#{backingBean.selectedChildren}"
                              label="Children" filter="true" filterMatchMode="startsWith">
            <p:ajax update="display" listener="#{backingBean.selectedSonChanged}" />
            <f:selectItems value="#{backingBean.children}" var="c" itemLabel="#{c.name}" itemValue="#{c}" />
        </p:selectCheckboxMenu>


        <p:outputPanel id="display">
            <p:dataList value="#{backingBean.selectedChildren}" var="sn" emptyMessage="No children selected">
                #{sn.name}
            </p:dataList>
        </p:outputPanel>

        <p:commandButton value="Submit" update="display, selectOne" />

</h:form>

</h:body>
</html>

完整的项目在这里：https://github.com/cenobyte321/jsfsamples/tree/master/selectcheckboxmenu

您可以在此处找到前面提到的互动视频： https://github.com/cenobyte321/jsfsamples/blob/master/selectcheckboxmenu/example1.mp4?raw=true

正如您在选择另一个＆＃34; Parent＆＃34;时所看到的那样。然后选择他们的孩子，以前的子列表被替换。如何正确修改此行为，以便先前选择的元素在selectCheckboxMenu中保持并显示为已选中？

编辑2：

我找到的一个解决方案是引入另一个变量，该变量将保存全局值，并将在侦听器方法中进行修改＆＃34; selectedSonChanged＆＃34;。这是相关代码：

import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.inject.Inject;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

@ManagedBean
@ViewScoped
public class BackingBean {

    private List<Parent> parents = new ArrayList<>();
    private List<Child> children = new ArrayList<>();
    private List<Child> selectedChildren = new ArrayList<>();

    private List<Child> globalSelectedChildren = new ArrayList<>();
    private Parent selectedParent = new Parent();

    @Inject
    FamilyService service;

    @PostConstruct
    public void init(){
        parents = service.findParents();
    }


    public void parentChanged(){
        children = new ArrayList<>();
        if(getSelectedParent() == null){
            return;
        }

        children = service.findChildrenByParent(getSelectedParent());
        selectedChildren = globalSelectedChildren.stream().filter(c -> c.getParent().equals(selectedParent)).collect(Collectors.toList());
        System.out.println(selectedChildren.size());
    }

    public void selectedSonChanged(){
        System.out.println(selectedChildren.size());
        globalSelectedChildren = globalSelectedChildren.stream().filter(c -> !c.getParent().equals(selectedParent)).collect(Collectors.toList());
        globalSelectedChildren.addAll(selectedChildren);
    }

    public List<Parent> getParents() {
        return parents;
    }

    public void setParents(List<Parent> parents) {
        this.parents = parents;
    }

    public List<Child> getChildren() {
        return children;
    }

    public void setChildren(List<Child> children) {
        this.children = children;
    }

    public List<Child> getSelectedChildren() {
        return selectedChildren;
    }

    public void setSelectedChildren(List<Child> selectedChildren) {
        this.selectedChildren = selectedChildren;
    }

    public Parent getSelectedParent() {
        return selectedParent;
    }

    public void setSelectedParent(Parent selectedParent) {
        this.selectedParent = selectedParent;
    }

    public List<Child> getGlobalSelectedChildren() {
        return globalSelectedChildren;
    }

    public void setGlobalSelectedChildren(List<Child> globalSelectedChildren) {
        this.globalSelectedChildren = globalSelectedChildren;
    }
}

XHTML：

<html xmlns="http://www.w3.org/1999/xhtml"
        xmlns:f="http://java.sun.com/jsf/core"
        xmlns:h="http://java.sun.com/jsf/html"
        xmlns:p="http://primefaces.org/ui">
<h:head></h:head>
<h:body>
<h:form id="selectOne">
    <p:messages autoUpdate="true" />

        <h:outputLabel for="parents" value="Parents:" />
        <p:selectOneMenu converter="#{parentConverter}" id="parents" value="#{backingBean.selectedParent}">
            <p:ajax update="children" listener="#{backingBean.parentChanged}" />
            <f:selectItem noSelectionOption="true" value="#{null}" itemLabel="None" />
            <f:selectItems value="#{backingBean.parents}" var="p" itemLabel="#{p.name}" itemValue="#{p}" />
        </p:selectOneMenu>


        <h:outputLabel for="children" value="Children:" />

        <p:selectCheckboxMenu converter="#{childConverter}"  id="children"
                              value="#{backingBean.selectedChildren}"
                              label="Children" filter="true" filterMatchMode="startsWith">
            <p:ajax update="display" listener="#{backingBean.selectedSonChanged}" />
            <f:selectItems value="#{backingBean.children}" var="c" itemLabel="#{c.name}" itemValue="#{c}" />
        </p:selectCheckboxMenu>


        <p:outputPanel id="display">
            <p:dataList value="#{backingBean.globalSelectedChildren}" var="sn" emptyMessage="No children selected">
                #{sn.name}
            </p:dataList>
        </p:outputPanel>

        <p:commandButton value="Submit" update="display, selectOne" />

</h:form>

</h:body>
</html>

以下是此解决方案的分支：https://github.com/cenobyte321/jsfsamples/tree/solution-1/selectcheckboxmenu

Primefaces依赖selectCheckboxMenu与全局集合

0 个答案: