Jak generować dynamiczne kolumny w JSF Datatable?

Question

chciałby mieć następującą strukturę tabeli danych:

+--------------------------------------------------------------+ 
|  dynamic  |  dynamic  |  dynamic  | 
|--------------------------------------------------------------| 
| col1 | col2 | col3 | col1 | col2 | col3 | col1 | col2 | col3 |  
|--------------------------------------------------------------| 
| data | data | data | data | data | data | data | data | data | 

Powodem tego jest to, że nie wiem ile kolumny mają być wyświetlane, dopóki nie poprosić o bazę danych. Kolumny w col1, col2, col3 są zawsze takie same.

Próbowałem z następujących DataTable:

<h:form id="form">  
     <h:panelGrid columns="3" style="margin:10px 0"> 
      <p:outputLabel for="template" value="Adid:" style="font-weight:bold"/> 
      <p:inputText id="template" value="#{reportingView.adId}" size="50"/> 
      <p:commandButton update="kpi_table" actionListener="#{reportingView.updateColumns}" value="Create Data" process="@parent" icon="ui-icon-refresh" oncomplete="PF('carsTable').clearFilters()"/> 
     </h:panelGrid> 

     <p:dataTable id="reportingTable" var="pi" value="#{reportingView.indicators}" widgetVar="indicatorTable" filteredValue="#{reportingView.filteredValues}">      
      <p:columns value="#{reportingView.columns}" var="column" columnIndexVar="colIndex" sortBy="#{pi[column.property]}" > 
       <f:facet name="header"> 
        <h:outputText value="#{column.header}" /> 
       </f:facet> 

       <p:columnGroup type="header"> 
        <p:row> 
         <p:column headerText="1" /> 
         <p:column headerText="2" /> 
         <p:column headerText="3" /> 
        </p:row> 
       </p:columnGroup> 


      </p:columns> 
     </p:dataTable> 
    </h:form> 

Ale, jak można sobie wyobrazić, że nie będzie działać - w columnGroup wydaje się być ignorowane. Sugeruję, że nie można połączyć struktury dynamicznej ze statycznymi kolumnami. Czy ktoś rozwiązał podobny problem?

thanks a lot

Answer 1

JSF mieć Value binding i Component binding. Zwykle używamy value binding. Dla mojego doświadczenia używam Component binding do generowania komponentów dynamicznych i sterowania przez program. (Np .: Tak jak Ty).

How does the 'binding' attribute work in JSF?

za pytanie, należy sprawdzić i spróbować Poniższy przykład program.

MockDb.java

Jest danych dla nagłówka i sub-cel. Może pochodzić z bazy danych.

import java.util.ArrayList; 
import java.util.List; 

public class MockDb { 
    public static List<Header> getHeaderList() { 
     List<Header> headerList = new ArrayList<Header>(); 

     List<SubCol> subColList_1 = new ArrayList<SubCol>(); 
     subColList_1.add(new SubCol("Col 1", "Data 1")); 
     subColList_1.add(new SubCol("Col 2", "Data 2")); 
     subColList_1.add(new SubCol("Col 3", "Data 3")); 
     headerList.add(new Header("Header 1", subColList_1)); 

     List<SubCol> subColList_2 = new ArrayList<SubCol>(); 
     subColList_2.add(new SubCol("Col 1", "Data 1")); 
     subColList_2.add(new SubCol("Col 2", "Data 2")); 
     subColList_2.add(new SubCol("Col 3", "Data 3")); 
     headerList.add(new Header("Header 2", subColList_2)); 


     List<SubCol> subColList_3 = new ArrayList<SubCol>(); 
     subColList_3.add(new SubCol("Col 1", "Data 1")); 
     subColList_3.add(new SubCol("Col 2", "Data 2")); 
     subColList_3.add(new SubCol("Col 3", "Data 3")); 
     subColList_3.add(new SubCol("Col 4", "Data 4")); 
     headerList.add(new Header("Header 3", subColList_3)); 


     List<SubCol> subColList_4 = new ArrayList<SubCol>(); 
     subColList_4.add(new SubCol("Col 1", "Data 1")); 
     subColList_4.add(new SubCol("Col 2", "Data 2")); 
     subColList_4.add(new SubCol("Col 3", "Data 3")); 
     subColList_4.add(new SubCol("Col 4", "Data 4")); 
     subColList_4.add(new SubCol("Col 5", "Data 5")); 
     headerList.add(new Header("Header 4", subColList_4)); 

     return headerList; 
    } 

    public static List<DataValue> getValueList() { 
     /*Create 5 rows for data array for 15 columns*/ 
     List<DataValue> valueList = new ArrayList<DataValue>(); 
     for(int i=1; i <=5; i++) { 
      DataValue data = new DataValue("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15"); 
      valueList.add(data); 
     } 
     return valueList; 
    } 
} 

Header.java

public class Header { 
    private String name; 
    private List<SubCol> subColList; 

    public Header(){ 
    } 

    public Header(String name, List<SubCol> subColList) { 
     this.name = name; 
     this.subColList = subColList; 
    } 
    //getter & setter 
} 

SubCol.java

public class SubCol { 
    private String name; 
    private String data; 

    public SubCol() { 
    } 

    public SubCol(String name, String data) { 
     this.name = name; 
     this.data = data; 
    } 
    //getter & setter 
} 

DataValue.java

public class DataValue { 
    private String data1; 
    private String data2; 
    private String data3; 
    private String data4; 
    private String data5; 
    private String data6; 
    private String data7; 
    private String data8; 
    private String data9; 
    private String data10; 
    private String data11; 
    private String data12; 
    private String data13; 
    private String data14; 
    private String data15; 

    public DataValue(){ 
    } 

    public DataValue(String data1, String data2, String data3, String data4, String data5, String data6, String data7, 
      String data8, String data9, String data10, String data11, String data12, String data13, String data14, 
      String data15) { 
     this.data1 = data1; 
     this.data2 = data2; 
     this.data3 = data3; 
     this.data4 = data4; 
     this.data5 = data5; 
     this.data6 = data6; 
     this.data7 = data7; 
     this.data8 = data8; 
     this.data9 = data9; 
     this.data10 = data10; 
     this.data11 = data11; 
     this.data12 = data12; 
     this.data13 = data13; 
     this.data14 = data14; 
     this.data15 = data15; 
    } 
    //getter & Setter 
} 

DynamicColumnBean.java

import java.util.List; 

import javax.annotation.PostConstruct; 
import javax.el.ELContext; 
import javax.el.ExpressionFactory; 
import javax.el.ValueExpression; 
import javax.faces.application.Application; 
import javax.faces.bean.ManagedBean; 
import javax.faces.bean.ViewScoped; 
import javax.faces.component.html.HtmlOutputText; 
import javax.faces.context.FacesContext; 

import org.primefaces.component.column.Column; 
import org.primefaces.component.columngroup.ColumnGroup; 
import org.primefaces.component.datatable.DataTable; 
import org.primefaces.component.row.Row; 

import com.kbzmai.skyfly.common.Header; 
import com.kbzmai.skyfly.common.MockDb; 
import com.kbzmai.skyfly.common.SubCol; 

@ManagedBean(name = "DynamicColumnBean") 
@ViewScoped 
public class DynamicColumnBean { 

    private DataTable myDataTable; 

    public DataTable getMyDataTable() { 
     return myDataTable; 
    } 

    public void setMyDataTable(DataTable myDataTable) { 
     this.myDataTable = myDataTable; 
    } 

    @PostConstruct 
    public void init() { 
     myDataTable = new DataTable(); 
     myDataTable.setValue(MockDb.getValueList()); 
     myDataTable.setVar("mydata"); 

     ColumnGroup columnGroup = new ColumnGroup(); 
     myDataTable.getChildren().add(columnGroup); 
     columnGroup.setType("header"); 
     List<Header> headerList = MockDb.getHeaderList(); 

     /*Create Column for Header*/   
     Row headerRow = new Row(); 
     columnGroup.getChildren().add(headerRow); 
     for(Header header : headerList) { 
      Column column = new Column(); 
      /*Make sure to set column span*/ 
      column.setColspan(header.getSubColList().size()); 
      headerRow.getChildren().add(column); 
      column.setHeaderText(header.getName()); 
     } 

     FacesContext fc = FacesContext.getCurrentInstance(); 
     Application application = fc.getApplication(); 
     ExpressionFactory ef = application.getExpressionFactory(); 
     ELContext elc = fc.getELContext(); 

     /*Create Column for Sub Column of current header*/  
     Row subColRow = new Row(); 
     columnGroup.getChildren().add(subColRow); 
     for(Header header : headerList) { 
      for(SubCol subCol : header.getSubColList()) { 
       Column column = new Column(); 
       subColRow.getChildren().add(column); 
       column.setHeaderText(subCol.getName()); 
      } 
     } 

     /*Create data row for 15 columns*/  
     for(int i=1; i <= 15; i++) { 
      ValueExpression valueExp = ef.createValueExpression(elc, "#{mydata.data" + i + "}", Object.class); 
      HtmlOutputText output = (HtmlOutputText)application.createComponent(HtmlOutputText.COMPONENT_TYPE); 
      output.setValueExpression("value", valueExp); 
      Column dataColumn = new Column(); 
      dataColumn.getChildren().add(output); 
      myDataTable.getChildren().add(dataColumn); 
     } 
    } 
} 

dynamicColumnTest.xhtml

<p:dataTable binding="#{DynamicColumnBean.myDataTable}"/>  

Wynik: