如何从ManagedBean获取原始数据列的顺序和宽度 [英] how to get primefaces datatable columns order and width from ManagedBean

问题描述

我使用的是原点4.0，JSF Mojarra 2.2.2
，这里是我的datatable代码：

  < p：dataTable id =tabexam
 paginatorPosition =bottom
 var =exam
 value =＃{dyna.examViewDataModel}
 widgetVar =examTable 
 emptyMessage =aucunrésultattrouvépour votre recherche
 paginator =true
 rows =40
 selection =＃{dyna.selectedExamen}
 filteredValue =＃{dyna.filteredexams}
 selectionMode =single
 resizableColumns =true
 draggableColumns =true
 paginatorTemplate ={CurrentPageReport} {FirstPageLink } {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}
 rowsPerPageTemplate =40,80,120> 
 
< p：columns value =＃{datatableBean.table}
 var =column
 headerText =＃{column.userListname}
 render =＃{column.visible}
 resizable =＃{column.resizable}
 width =＃{column.width}
 columnIndexVar =colIndex> 
 
< h：panelGroup> 
< p：outputLabel value =＃{column.dbname}styleClass =fonty/> 
< / h：panelGroup> 
 
< / p：columns> 
 
< / p：dataTable> 
  

这里是我迄今为止所尝试过的，但是在控制台中为getHeaderText空字符串为空宽度太大了，我想知道我失踪了什么

  UIViewRoot view = FacesContext.getCurrentInstance（）。getViewRoot（）; 
 DataTable tabler =（DataTable）view.findComponent（：form1：tabexam）; 
列表< UIColumn> coler = tabler.getColumns（）; （int i = 0; i< coler.size（）; i ++）{
 
 System.out.println（//////// /////////）; 
 System.out.println（coler.get（i）.getValueExpression（headerText）。getValue（FacesContext.getCurrentInstance（）。getELContext（）））; 
 System.out.println（coler.get（i）.getHeaderText（））; 
 System.out.println（coler.get（i）.isRendered（））; 
 System.out.println（coler.get（i）.isResizable（））; 
 System.out.println（coler.get（i）.getWidth（））; 
 System.out.println（///////////////）; 
 
} 
 System.out.println（coler.size（））; 
  

请注意， coler.size（）给出数据表上显示的列数。
，但$ coler.get（i）.getHeaderText（）总是给空字符串。

解决方案

你错了什么：

1. 不要嵌套 p：column in p：columns



2. DataTable.getColumns不返回您的期望：

     public List< UIColumn> getColumns（）{
    if（columns == null）{
    columns = new ArrayList< UIColumn>（）; 
    FacesContext context = getFacesContext（）; 
    char separator = UINamingContainer.getSeparatorChar（context）; （UIComponent child：this.getChildren（））{
    if（child instanceof Column）{
    columns.add（（UIColumn）child）; 
    
    
   } 
    else if（child instanceof Columns）{
   列uiColumns =（Columns）child; 
    String uiColumnsClientId = uiColumns.getClientId（context）; （int i = 0; i< uiColumns.getRowCount（）; i ++）{
    DynamicColumn dy​​naColumn = new DynamicColumn（i，uiColumns）; 
    
    
    dynaColumn.setColumnKey（uiColumnsClientId + separator + i）; 
    columns.add（dynaColumn）; 
   } 
   } 
   } 
   } 
    
   返回列; 
   } 
     

仿真：每列只有 columnKey ，正如你所说，正确的列数。

一般来说， p：columns 是一个组件，当您从控制器层访问它时，您必须参考其声明（单个组件）而不是其REPRESENTATION（多列）＃{datatableBean支持 p：columns ，所以



1. .table} 您应该已经以反向设计的方式拥有您尝试从DataTable组件获取的所有信息。

更新

哦，现在我意识到你想要做什么您必须使用事件监听器。

从PF展示：

 < p：dataTable var =carvalue =＃{tableBean.carsSmall}widgetVar =carsdraggableRows =true> 
 
< p：ajax event =colReorderlistener =＃{tableBean.onColReorder}update =：some：component/> 
 
< p：ajax event =colResizelistener =＃{tableBean.onColResize}update =：some：component/> 
 
<！ - 这里列 - > 
< / p：dataTable> 
  

在支持bean和mantain中监听这些事件，这些信息应该可以解决你的问题。
$ b

更新2

whew，这根本不简单。

由于原始动态列调整大小的错误（至少对我的尝试）和不完整的列重新排序事件实现，这是出来的：

 < h：form id =form> 
< h：panelGroup id =model> 
< ui：repeat var =column2value =＃{testBean.columnList2}> 
< div>＃{column2.title}  - ＃{column2.width}< / div> 
< / ui：repeat> 
< / h：panelGroup> 
 
< p：dataTable var =elemvalue =＃{testBean.elementList}resizableColumns =truedraggableColumns =true> 
< p：ajax event =colReorderlistener =＃{testBean.onColumnReorder}update =：form：model/> 
< p：ajax event =colResizelistener =＃{testBean.onColumnResize}update =：form：model/> 
 
< c：forEach var =columnitems =＃{testBean.columnList}> 
< p：column headerText =＃{column.title}rendered =＃{column.visible}width =＃{column.width}> 
< f：attribute name =myColvalue =＃{column}/> 
< span>＃{elem [column.property]}< / span> 
< / p：column> 
< / c：forEach> 
< / p：dataTable> 
< / h：form> 
  

和这个bean：

  @ManagedBean 
 @ViewScoped 
 public class TestBean implements Serializable 
 {
 private static final long serialVersionUID = 1L; 
 
私人列表< MyColumn> columnList; 
私人列表< MyColumn> columnList2; 
私人列表< MyElement> elementList; 
 
 public class MyColumn 
 {
 private String title; 
 private String property; 
 private boolean visible = true; 
 private boolean resizable = true; 
 private int width = 100; 
 
 public MyColumn（String title，String property，boolean visible，boolean resizable，int width）
 {
 super（）; 
 this.title = title; 
 this.property = property; 
 this.visible = visible; 
 this.resizable = resizable; 
 this.width = width; 
} 
 
 // getter和setter 
} 
 
 public class MyElement 
 {
 private String code; 
 private String name; 
 private String type; 
 
 public MyElement（String code，String name，String type）
 {
 super（）; 
 this.code = code; 
 this.name = name; 
 this.type = type; 
} 
 
 // getter和setter 
} 
 
 @PostConstruct 
 public void init（）
 {
 columnList = new ArrayList<>（）; 
 columnList.add（new MyColumn（element code，code，true，true，100））; 
 columnList.add（new MyColumn（element name，name，true，true，100））; 
 columnList.add（new MyColumn（element type，type，true，true，100））; 
 
 columnList2 = new ArrayList<（columnList）; 
 
 elementList = new ArrayList<>（）; 
 elementList.add（new MyElement（001，foo，normal））; 
 elementList.add（new MyElement（002，bar，strange））; 
 elementList.add（new MyElement（003，xyz，normal））; 
 elementList.add（new MyElement（004，abc，nothing））; 
} 
 
 public void onColumnResize（ColumnResizeEvent event）
 {
 UIColumn column = event.getColumn（）; 
 int width = event.getWidth（）; 
 
 UIComponent colComponent =（UIComponent）列; 
 MyColumn myCol =（MyColumn）colComponent.getAttributes（）。get（myCol）; 
 
 myCol.setWidth（width）; 
} 
 
 public void onColumnReorder（AjaxBehaviorEvent event）
 {
 DataTable table =（DataTable）event.getSource（）; 
 
 columnList2.clear（）; 
 
（UIColumn列：table.getColumns（））
 {
 UIComponent colComponent =（UIComponent）列; 
 
 MyColumn myCol =（MyColumn）colComponent.getAttributes（）。get（myCol）; 
 columnList2.add（myCol）; 
} 
} 
 
 // getters和setter 
 
} 
  

更新的代码，您可以在 columnList2 中找到有序列。现在也以形式显示。
现在您可以使用 columnList2 来存储oreder和宽度到db。

i'm using primefaces 4.0, JSF Mojarra 2.2.2 and here is my datatable code :

<p:dataTable id="tabexam"
             paginatorPosition="bottom"
             var="exam"
             value="#{dyna.examViewDataModel}"
             widgetVar="examTable"
             emptyMessage="aucun résultat trouvé pour votre recherche"
             paginator="true"
             rows="40" 
             selection="#{dyna.selectedExamen}"
             filteredValue="#{dyna.filteredexams}"
             selectionMode="single"
             resizableColumns="true"  
             draggableColumns="true"
             paginatorTemplate="{CurrentPageReport} {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"  
             rowsPerPageTemplate="40,80,120">

<p:columns value="#{datatableBean.table}"
           var="column"
           headerText="#{column.userListname}"
           rendered="#{column.visible}"
           resizable="#{column.resizable}"
           width="#{column.width}"
           columnIndexVar="colIndex">

   <h:panelGroup>
             <p:outputLabel value="#{column.dbname}" styleClass="fonty"/>
   </h:panelGroup>

 </p:columns>

</p:dataTable>

Here what I've tried so far, but I get empty Strings for getHeaderText in the console and empty width too, i wonder what i'm missing

UIViewRoot view = FacesContext.getCurrentInstance().getViewRoot();
    DataTable tabler = (DataTable) view.findComponent(":form1:tabexam");
    List<UIColumn> coler = tabler.getColumns();

    for (int i = 0; i < coler.size(); i++) {

        System.out.println("/////////////////");
        System.out.println(coler.get(i).getValueExpression("headerText").getValue(FacesContext.getCurrentInstance().getELContext()));
        System.out.println(coler.get(i).getHeaderText());
        System.out.println(coler.get(i).isRendered());
        System.out.println(coler.get(i).isResizable());
        System.out.println(coler.get(i).getWidth());
        System.out.println("/////////////////");

    }
 System.out.println(coler.size());

Note that coler.size() gives the number of columns shown on the datatable. but the coler.get(i).getHeaderText() always gives empty String.

解决方案

you are mistaking something:

1. do not nest p:column inside p:columns

2. DataTable.getColumns does not return what you expect:

   public List<UIColumn> getColumns() {
       if(columns == null) {
           columns = new ArrayList<UIColumn>();
           FacesContext context = getFacesContext();
           char separator = UINamingContainer.getSeparatorChar(context);
   
           for(UIComponent child : this.getChildren()) {
               if(child instanceof Column) {
                   columns.add((UIColumn) child);
               }
               else if(child instanceof Columns) {
                   Columns uiColumns = (Columns) child;
                   String uiColumnsClientId = uiColumns.getClientId(context);
   
                   for(int i=0; i < uiColumns.getRowCount(); i++) {
                       DynamicColumn dynaColumn = new DynamicColumn(i, uiColumns);
                       dynaColumn.setColumnKey(uiColumnsClientId + separator + i);
                       columns.add(dynaColumn);
                   }
               }
           }
       }
   
       return columns;
   }
   

this returns a synthetic emulation: only columnKey per column, and, as you stated, the correct number of columns.

generally speaking, p:columns is ONE component and when you access it from controller layer, you have to refer to its DECLARATION (single component) instead of its REPRESENTATION (multiple columns)

1. since you are backing p:columns with your #{datatableBean.table} you should already have all the information you are trying to get from DataTable component, in a reverse-engineered fashion.

update

oh, now i realize what you want to do. you have to use event listeners for that.

from PF showcase:

<p:dataTable var="car" value="#{tableBean.carsSmall}" widgetVar="cars" draggableRows="true">  

    <p:ajax event="colReorder" listener="#{tableBean.onColReorder}" update=":some:component" />  

    <p:ajax event="colResize" listener="#{tableBean.onColResize}" update=":some:component"/>    

    <!-- columns here -->  
</p:dataTable> 

listening for these events in backing bean and mantain these informations should solve your problem

update 2

whew, it was not simple at all.

due to Primefaces bug for dynamic column resizing (at least for my tries) and incomplete column reordering event implementation, this is what came out:

<h:form id="form">
    <h:panelGroup id="model">
        <ui:repeat var="column2" value="#{testBean.columnList2}">
            <div>#{column2.title} - #{column2.width}</div>
        </ui:repeat>
    </h:panelGroup>

    <p:dataTable var="elem" value="#{testBean.elementList}" resizableColumns="true" draggableColumns="true">
        <p:ajax event="colReorder" listener="#{testBean.onColumnReorder}" update=":form:model" />  
        <p:ajax event="colResize" listener="#{testBean.onColumnResize}" update=":form:model"/>  

        <c:forEach var="column" items="#{testBean.columnList}">
            <p:column headerText="#{column.title}" rendered="#{column.visible}" width="#{column.width}">
                <f:attribute name="myCol" value="#{column}"/>
                <span>#{elem[column.property]}</span>
            </p:column>
        </c:forEach>
    </p:dataTable>
</h:form>

and this bean:

@ManagedBean
@ViewScoped
public class TestBean implements Serializable
{
    private static final long serialVersionUID = 1L;

    private List<MyColumn> columnList;
    private List<MyColumn> columnList2;
    private List<MyElement> elementList;

    public class MyColumn
    {
        private String title;
        private String property;
        private boolean visible = true;
        private boolean resizable = true;
        private int width = 100;

        public MyColumn(String title, String property, boolean visible, boolean resizable, int width)
        {
            super();
            this.title = title;
            this.property = property;
            this.visible = visible;
            this.resizable = resizable;
            this.width = width;
        }

        // getters and setters
    }

    public class MyElement
    {
        private String code;
        private String name;
        private String type;

        public MyElement(String code, String name, String type)
        {
            super();
            this.code = code;
            this.name = name;
            this.type = type;
        }

        // getters and setters
    }

    @PostConstruct
    public void init()
    {
        columnList = new ArrayList<>();
        columnList.add(new MyColumn("element code", "code", true, true, 100));
        columnList.add(new MyColumn("element name", "name", true, true, 100));
        columnList.add(new MyColumn("element type", "type", true, true, 100));

        columnList2 = new ArrayList<>(columnList);

        elementList = new ArrayList<>();
        elementList.add(new MyElement("001", "foo", "normal"));
        elementList.add(new MyElement("002", "bar", "strange"));
        elementList.add(new MyElement("003", "xyz", "normal"));
        elementList.add(new MyElement("004", "abc", "nothing"));
    }

    public void onColumnResize(ColumnResizeEvent event)
    {
        UIColumn column = event.getColumn();
        int width = event.getWidth();

        UIComponent colComponent = (UIComponent) column;
        MyColumn myCol = (MyColumn) colComponent.getAttributes().get("myCol");

        myCol.setWidth(width);
    }

    public void onColumnReorder(AjaxBehaviorEvent event)
    {
        DataTable table = (DataTable) event.getSource();

        columnList2.clear();

        for(UIColumn column : table.getColumns())
        {
            UIComponent colComponent = (UIComponent) column;

            MyColumn myCol = (MyColumn) colComponent.getAttributes().get("myCol");
            columnList2.add(myCol);
        }
    }

    // getters and setters

}

updated code, you can find ordered columns in columnList2. now are also shown in the form. now you can use columnList2 to store oreder and widths to db.

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