在datatable中表示静态和动态列 [英] Primefaces static and dynamic columns in datatable

问题描述

我正在使用Primefaces 5.0创建一个动态数据。

我的DataObject有一些必需的字段和一个可选的tupel（键值对）列表。可选列表的大小可能会有所不同。因此，我需要一个动态机制来在Primefaces.DataTable中显示DataObject列表。

我的方法看起来像：

  public class DataObject {
 private String staticval1; 
 private String staticval2; 
 
私人列表< Tupel>可选值
 
 
 // .. getter，setter，hashCode，toString ..... 
} 
 
 public class Tupel {
 private字符串id 
 private String value; 
} 
 
 @ManagedBean 
 @ViewScoped 
 public class TableOverviewBean {
 private List< DataObject>数据; 
 
 @EJB 
私人IMyDao myDao; 
 
 @PostConstruct 
 public void init（）{
 data = myDao.findAll（）; 
} 
 
 public List< DataObject> getData（）{
返回数据; 
} 
 
 public void setData（List< DataObject> data）{
 this.data = data; 
} 
} 
  

 < h：form> 
< p：dataTable value =＃{tableOverviewBean.data}var =data> 
< p：column headerText =static1> 
< h：outputText value =＃{data.staticval1}/> 
< / p：column> 
 
< p：column headerText =static2> 
< h：outputText value =＃{data.staticval2}/> 
< / p：column> 
 
< p：columns value =＃{data.optionalValues}var =optheaderText =＃{opt.id}> 
< h：outputText value =＃{opt.value}/> 
< / p：columns> 
< / p：dataTable> 
< / h：form> 
  

但这不行。动态列不呈现。
如何解决我的问题？

编辑：
预期结果：

  staticval1 | staticval2 | dynamic_id1 | dynamic_id2 | ... | dynmic_idn 
 --------------------------------------------- ------------------------- 
 static1a | static2a | dyna_value1a | dyna_value2a | ... | dyna_valu3a 
 static1b | static2b | dyna_value1b | dyna_value2b | ... | dyna_valu3b 
 static1c | static2c | dyna_value1c | dyna_value2c | ... | dyna_valu3c 
  

解决方案

不可能根据行数据。想象一下，第1行有2列，第2行有6列，第3行有1列，你如何在HTML中生成技术上有效的表？每行必须具有相同数量的列。

您有两个选项，具体取决于是否可以更改模型：

1. 如果您无法更改模型，则需要替换< p：columns> 通过单个< p：column> ，并使用嵌套循环循环使用＃{data.optionalValues} 例如< ui：repeat> 或者甚至可以是另一个< p：dataTable>< p：columns> / p>
   
   

    < p：column> 
   < p：dataTable value =><！ - 空字符串作为值强制1行。 - > 
   < p：columns value =＃{data.optionalValues}var =optheaderText =＃{opt.id}> 
   ＃{opt.value} 
   < / p：columns> 
   < / p：dataTable> 
   < / p：column> 
     




2. 如果您可以更改模型，则需要让 < p：columns value> 指向一个bean属性而不是一个row属性，所以每行都完全一样。如果您替换列表< Tupel>可选值由映射< String，Tupel>可选值其中的密钥是 Tupel＃id ，并添加一个列表< String> 属性该bean包含所有可用的 Tupel＃id 值。

    < p ：columns value =＃{tableOverviewBean.availableTupelIds}var =idheaderText =＃{id}> 
   ＃{data.optionalValues [id] .value} 
   < / p：columns> 
     

I am using Primefaces 5.0 to create a dynamic datatable.

My DataObject has some required fields and a List of optional "tupel" (key-value pair). The optional list may vary in size. Therefore I need a dynamic mechanism to show a List of DataObject in Primefaces.DataTable.

My approach looks like:

public class DataObject {
    private String staticval1;
    private String staticval2;

    private List<Tupel> optionalValues;


    // .. getter, setter, hashCode, toString.....
}

public class Tupel{
    private String id;
    private String value;
}

@ManagedBean
@ViewScoped
public class TableOverviewBean {
    private List<DataObject> data;

    @EJB
    private IMyDao myDao;

    @PostConstruct
    public void init() {
        data = myDao.findAll();
    }

    public List<DataObject> getData() {
        return data;
    }

    public void setData(List<DataObject> data) {
        this.data = data;
    }
}

    <h:form>
        <p:dataTable value="#{tableOverviewBean.data}" var="data">
            <p:column headerText="static1">
                <h:outputText value="#{data.staticval1}" />
            </p:column>

            <p:column headerText="static2">
                <h:outputText value="#{data.staticval2}" />
            </p:column>

            <p:columns value="#{data.optionalValues}" var="opt" headerText="#{opt.id}">
                <h:outputText value="#{opt.value}" />
            </p:columns>
        </p:dataTable>
    </h:form>

But this does not work. The dynamic columns are not rendered. How can I solve my problem?

EDIT: Expected result:

staticval1 | staticval2 | dynamic_id1 | dynamic_id2 | ... | dynmic_idn
----------------------------------------------------------------------
static1a   | static2a   | dyna_value1a| dyna_value2a | ... | dyna_valu3a
static1b   | static2b   | dyna_value1b| dyna_value2b | ... | dyna_valu3b
static1c   | static2c   | dyna_value1c| dyna_value2c | ... | dyna_valu3c

解决方案

It isn't possible to define columns based on row data. Imagine that row 1 has 2 columns, row 2 has 6 columns, row 3 has 1 column, etc how would you ever produce a technically valid table in HTML? Each row must have the same amount of columns.

You've 2 options, depending on whether can change the model or not:

1. If you can't change the model, then you need to replace that <p:columns> by a single <p:column> and loop over the #{data.optionalValues} using a nested loop with e.g. <ui:repeat> or perhaps even another <p:dataTable><p:columns>:

   <p:column>
       <p:dataTable value=""><!-- Empty string as value forces 1 row. -->
           <p:columns value="#{data.optionalValues}" var="opt" headerText="#{opt.id}">
               #{opt.value}
           </p:columns>
       </p:dataTable>
   </p:column>
   

2. If you can change the model, then you need to let <p:columns value> point to a bean property instead of to a row property, so that it's exactly the same for every row. This works if you replace List<Tupel> optionalValues by Map<String, Tupel> optionalValues where the key is Tupel#id and add a List<String> property to the bean containing all available Tupel#id values.

   <p:columns value="#{tableOverviewBean.availableTupelIds}" var="id" headerText="#{id}">
       #{data.optionalValues[id].value}
   </p:columns>
   

这篇关于在datatable中表示静态和动态列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！