selectonemenu inside table in jsf2

问题

I have a table with 2 selectOneMenu components.

I would like that once a record was chosen in the first selectOneMenu component it will update the other selectOneMenu with Ajax in the same row.

My table:

<p:dataTable value="#{myBean.myInfo}" var="myInfo">
    <p:column>
        <f:facet name="header">Group</f:facet>
        <h:selectOneMenu value="#{myInfo.myInfoType.code}">
            <f:selectItems value="#{myBean.myList}" />
            <f:ajax event="change" execute="@this" listener="#{myBean.refershNames}" render="myNames"/>
        </h:selectOneMenu>
    </p:column>
    <p:column>
        <f:facet name="header">Name</f:facet>
        <h:selectOneMenu id="myNames" value="#{myInfo.myInfoType.secondCode}">
            <f:selectItems value="#{myBean.mySecondList}" />
        </h:selectOneMenu>
    </p:column>
<p:dataTable>

In the bean I have:

List<SelectItem> myList,mySecondList;

public void refershNames(AjaxBehaviorEvent event){
    //how can I retrieve the selected item and update the relevant record?
}

How can I do it with Ajax? I am using JSF2

回答1:

Wrap the datatable value in DataModel<E> so that you can obtain the myInfo object in question by DataModel#getRowData(). So,

DataModel<MyInfo> myInfoModel; // +getter

@PostConstruct
public void init() {
    myInfo = myInfoDAO.list();
    myInfoModel = new ListDataModel<MyInfo>(myInfo);
}

with

<h:dataTable value="#{myBean.myInfoModel}" var="myInfo">

and

public void refreshNames(AjaxBehaviorEvent event){
    MyInfo myInfo = myInfoModel.getRowData();
    // Get code and update secondCode.
}

---

Update as per the comments, here is the testcase I created after you told that it didn't work. It worked for me with Mojarra 2.0.3 on both Tomcat 7.0.5 and Glassfish 3.0.1.

com.example.Item

public class Item {

    private String value1;
    private String value2;

    // Generate public getters/setters.    
}

com.example.Bean

@ManagedBean
@ViewScoped
public class Bean {

    private List<Item> items;
    private DataModel<Item> model;
    private List<String> list;

    @PostConstruct
    public void init() {
        items = Arrays.asList(new Item(), new Item(), new Item());
        model = new ListDataModel<Item>(items);
        list = Arrays.asList("one", "two", "three");
    }

    public void change(AjaxBehaviorEvent e) {
        Item item = model.getRowData();
        item.setValue2(item.getValue1());
    }

    public DataModel<Item> getModel() {
        return model;
    }

    public List<String> getList() {
        return list;
    }

}

test.xhtml

<h:form>
    <h:dataTable value="#{bean.model}" var="item">
        <h:column>
            <h:selectOneMenu value="#{item.value1}">
                <f:selectItem itemLabel="select..." itemValue="#{null}" />
                <f:selectItems value="#{bean.list}" />
                <f:ajax execute="@this" listener="#{bean.change}" render="list2" />
            </h:selectOneMenu>
        </h:column>
        <h:column>
            <h:selectOneMenu id="list2" value="#{item.value2}">
                <f:selectItem itemLabel="select..." itemValue="#{null}" />
                <f:selectItems value="#{bean.list}" />
            </h:selectOneMenu>
        </h:column>
    </h:dataTable>
</h:form>

This testcase proves that whenever you change a dropdown value in the 1st column, then the dropdown value in the 2nd column in the same row will be reflected to retrieve the same value.

回答2:

i had the same issue and after a lot of trial and error this worked for me

<p:column style="width:50%">
                    <f:facet name="header">
                        <h:outputText value="Criteria" />
                    </f:facet>
                    <h:selectOneMenu value="#{option.predefinedMessageId}"
                        valueChangeListener="#{predefinedMessageBean.predefinedMessageChangeListener}">
                        <f:selectItems
                            value="#{campaignRecipientCriteriaBean.messages}"
                            var="predef" itemLabel="#{predef.fieldName}"
                            itemValue="#{predef.predefinedMessageId}" />
                            <p:ajax event="change" update="optionsList"/>

                    </h:selectOneMenu>
                </p:column>


                <p:column>
                    <f:facet name="header">
                        <h:outputText value="Options" />
                    </f:facet>
                    <p:outputPanel id="optionsList">
                    <h:selectOneMenu
                        value="#{option.predefinedMessageOptionId}">
                        <f:selectItems
                            value="#{predefinedMessageBean.emptyOptionBeansList}"
                            var="predef" itemLabel="#{predef.optionCaption}"
                            itemValue="#{predef.predefinedMessageOptionId}" />

                    </h:selectOneMenu>
                    </p:outputPanel>
                </p:column>

valuechangelistener is

public void predefinedMessageChangeListener(ValueChangeEvent e)
{

        getPredefinedMessageOptions(Integer.parseInt(e.getNewValue().toString()));


}

This is simple and works perfectly for me , as the message that i choose in the first column updates the options in the second column and its done through ajax. But then again, i m still learning and alot of my knowledge of jsf is from material from @BalusC blog :), so if this approach has some flaws, please lemme know.

来源：https://stackoverflow.com/questions/5107792/selectonemenu-inside-table-in-jsf2