如何迭代一个HashMap，可以使用原子数组 [英] How to iterate a HashMap with primefaces selectable datatatable

问题描述

我已经尝试过不同的解决方案，但没有一个在我的情况下工作。我希望这个数据表中的所有行都可以选择。问题似乎是可能覆盖对象的< ui：repeat

我的bean ：

  @ManagedBean 
 @ViewScoped 
 public class Chat {
 
 private static Map< String，List< ChatObject>> chat = new LinkedHashMap< String，List< ChatObject>>（）; 
 private ChatObject selectedChatObject; 
 
 public void onChatRowSelection（）{
 if（getSelectedChatObject（）！= null）{
 System.out.println（test）; 
} 
} 
 
 public List< Map.Entry< String，List< ChatObject>>> getChatList（）{
 Set< Map.Entry< String，List< ChatObject>>> productSet = chat.entrySet（）; 
 return new ArrayList< Map.Entry< String，List< ChatObject>>>（productSet）; 
} 
 
 @PostConstruct 
 public void postConstructMethod（）{
 
 if（chat.isEmpty（））{
 
列表< ChatObject> objectsList1 = new ArrayList< ChatObject>（）; 
 objectsList1.add（new ChatObject（3369818，1，1））; 
 objectsList1.add（new ChatObject（3369819，2，2））; 
 objectsList1.add（new ChatObject（3369820，3，3））; 
 
 chat.put（聊天主题1，objectsList1）; 
 
列表< ChatObject> objectsList2 = new ArrayList< ChatObject>（）; 
 objectsList2.add（new ChatObject（3369813，4，4））; 
 objectsList2.add（new ChatObject（3369815，5，5））; 
 chat.put（聊天主题2，objectsList2）; 
} 
 
} 
 
 public ChatObject getSelectedChatObject（）{
 return selectedChatObject; 
} 
 
 public void setSelectedChatObject（ChatObject selectedChatObject）{
 this.selectedChatObject = selectedChatObject; 
} 
} 
  

我的JSF：

 <！DOCTYPE html PUBLIC -  // W3C // DTD XHTML 1.0 Transitional // EN
http：//www.w3。 org / TR / xhtml1 / DTD / xhtml1-transitional.dtd> 
 
< html xmlns =http://www.w3.org/1999/xhtml
 xmlns：ui =http://xmlns.jcp.org/jsf/facelets 
 xmlns：h =http://xmlns.jcp.org/jsf/html
 xmlns：f =http://xmlns.jcp.org/jsf/core
 xmlns：p =http://primefaces.org/ui
 xmlns：fn =http://java.sun.com/jsp/jstl/functions> 
 
< h：form id =formenctype =multipart / form-dataacceptcharset =ISO-8859-1> 
 
< ui：repeat value =＃{chat.chatList}var =chatEntry> 
 
< h2>< h：outputText value =＃{chatEntry.key}/>< / h2> 
< br /> 
 
< p：dataTable 
 value =＃{chatEntry.value}
 var =chatEntryVar
 widgetVar =chatTableWV
 styleClass =geralBorderless
 style =cursor：pointer
 rowKey =＃{chatEntryVar.id}
 rendered =true
 selectionMode =single
 selection =＃{chat.selectedChatObject}
 paginatorAlwaysVisible =false> 
 
< p：ajax事件=rowSelect
 listener =＃{chat.onChatRowSelection}
 oncomplete =chatTableWV.unselectAllRows（）;> 
 
< / p：ajax> 
 
< p：column> 
< h：outputText value =＃{chatEntryVar.name}/> 
< / p：column> 
< / p：dataTable> 
 
< / ui：repeat> 
< / h：form> 
< / html> 
  

我的地图中的所有5 ChatObject 成功显示在我的页面。但是，当我点击与我添加到的第二个列表相关的行时， c 方法 只会打印test我的地图： objectList2 。 当我点击第一个列表的行添加 objectList1 ，当系统进入 onChatRowSelection 方法， selectedChatObject 将为null。如何解决这个问题？

谢谢！

解决方案

在这里：

 < ui：repeat ...> 
< p：dataTable ... widgetVar =chatTableWV> 
< p：ajax ... oncomplete =chatTableWV.unselectAllRows（）;> 
  

多个数据表被分配完全相同的 widgetVar 在JavaScript范围内的名称。生成以下JavaScript代码：

  window ['chatTableWV'] = new Widget（tableElement1）; 
 window ['chatTableWV'] = new Widget（tableElement2）; 
 window ['chatTableWV'] = new Widget（tableElement3）; 
 // ... 
  

基本上，每次迭代都会覆盖分配给声明的最后一个对象 widgetVar 名称，直到它最后引用最后一个。最后一个的所有小部件基本都不可用，导致它们不再具有行选择的功能。

通过给它们分配唯一的 widgetVar 。您可以使用< ui：repeat> 的迭代索引。

 < ui：repeat ... varStatus =loop> 
< p：dataTable ... widgetVar =chatTableWV _＃{loop.index}> 
< p：ajax ... oncomplete =chatTableWV _＃{loop.index} .unselectAllRows（）;> 
  

生成以下JavaScript代码：

  window ['chatTableWV_0'] = new Widget（tableElement1）; 
 window ['chatTableWV_1'] = new Widget（tableElement2）; 
 window ['chatTableWV_2'] = new Widget（tableElement3）; 
 // ... 
  

最后，PrimeFaces小部件管理器可以找到它们。 p>

I have tried different solutions but none is working in my case. I want all the rows in this datatable to be selectable. The problem seems to be the <ui:repeatthat is probably overriding the objects...

My bean:

@ManagedBean
@ViewScoped
public class Chat {

    private static Map<String, List<ChatObject>> chat = new LinkedHashMap<String, List<ChatObject>>();
    private ChatObject selectedChatObject;

    public void onChatRowSelection(){
        if(getSelectedChatObject() != null){
            System.out.println("test");
        }
    }

    public List<Map.Entry<String, List<ChatObject>>> getChatList() {
        Set<Map.Entry<String, List<ChatObject>>> productSet = chat.entrySet();
        return new ArrayList<Map.Entry<String, List<ChatObject>>>(productSet);
    }

    @PostConstruct
    public void postConstructMethod() { 

        if(chat.isEmpty()){

            List<ChatObject> objectsList1 = new ArrayList<ChatObject>();
            objectsList1.add(new ChatObject("3369818", "1", "1"));
            objectsList1.add(new ChatObject("3369819", "2", "2"));
            objectsList1.add(new ChatObject("3369820", "3", "3"));

            chat.put("Chat Topic 1", objectsList1);

            List<ChatObject> objectsList2 = new ArrayList<ChatObject>();        
            objectsList2.add(new ChatObject("3369813", "4", "4"));
            objectsList2.add(new ChatObject("3369815", "5", "5"));
            chat.put("Chat Topic 2", objectsList2);
        }

    }

    public ChatObject getSelectedChatObject() {
        return selectedChatObject;
    }

    public void setSelectedChatObject(ChatObject selectedChatObject) {
        this.selectedChatObject = selectedChatObject;
    }
}

My JSF:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://xmlns.jcp.org/jsf/facelets"
    xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:f="http://xmlns.jcp.org/jsf/core"
    xmlns:p="http://primefaces.org/ui"
    xmlns:fn="http://java.sun.com/jsp/jstl/functions">

<h:form id="form" enctype="multipart/form-data" acceptcharset="ISO-8859-1">

<ui:repeat value="#{chat.chatList}" var="chatEntry">

    <h2><h:outputText value="#{chatEntry.key}" /></h2>
    <br />

    <p:dataTable 
        value="#{chatEntry.value}" 
        var="chatEntryVar"
        widgetVar="chatTableWV" 
        styleClass="geralBorderless"
        style="cursor:pointer" 
        rowKey="#{chatEntryVar.id}" 
        rendered="true"
        selectionMode="single" 
        selection="#{chat.selectedChatObject}"
        paginatorAlwaysVisible="false">

        <p:ajax event="rowSelect"
            listener="#{chat.onChatRowSelection}" 
            oncomplete="chatTableWV.unselectAllRows();">

        </p:ajax>

        <p:column>
            <h:outputText value="#{chatEntryVar.name}" />
        </p:column>
    </p:dataTable>

</ui:repeat>
</h:form>
</html>

All the 5 ChatObject in my Map are successfully shown in my page. But onChatRowSelection method will only print "test" when I click in the rows related to the second list I added to my map: objectList2. When I click in the lines from the first list I added objectList1, when the system enters in the onChatRowSelection method, selectedChatObject will be null. How can I fix this?

Thanks!

解决方案

Your problem is here:

<ui:repeat ...>
    <p:dataTable ... widgetVar="chatTableWV">
       <p:ajax ... oncomplete="chatTableWV.unselectAllRows();">

Multiple data tables are been assigned exactly the same widgetVar name in JavaScript scope. In effects, the following JavaScript code is generated:

window['chatTableWV'] = new Widget(tableElement1);
window['chatTableWV'] = new Widget(tableElement2);
window['chatTableWV'] = new Widget(tableElement3);
// ...

Basically, every iteration overrides the last object assigned to the declared widgetVar name until it ends up referencing the last one. All widgets expect of the last one are basically unavailable, causing them to not be functional anymore as to row selection.

Fix it accordingly by giving them each an unique widgetVar. You could use the iteration index of <ui:repeat> for this.

<ui:repeat ... varStatus="loop">
    <p:dataTable ... widgetVar="chatTableWV_#{loop.index}">
       <p:ajax ... oncomplete="chatTableWV_#{loop.index}.unselectAllRows();">

This way the following JavaScript code is generated:

window['chatTableWV_0'] = new Widget(tableElement1);
window['chatTableWV_1'] = new Widget(tableElement2);
window['chatTableWV_2'] = new Widget(tableElement3);
// ...

And finally PrimeFaces widget manager can find them all.

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