h:inputText inside ui:repeater displays wrong valu

问题:

I've got a JSF page with a ui:repeater tag that simply displays a list of strings and some controls to add a string to a list. When adding a string I use ajax to update the repeater tag and have the new string be shown immediately without the page refresh. Here's how my page looks like:

<h:body>
    <h:form>
        <p:inputText id="name" value="#{testController.newString}"/>
        <p:commandButton value="Add" actionListener="#{testController.addString}" update="strings" />
    </h:form>       

    <h:panelGroup id="strings">         
        <ui:repeat var="str" value="#{stringModel.strings}" varStatus="stringData">                                                                                                             
            <div>                                       
                <h:outputText value="#{str}" />
                <h:inputText value="#{str}" />
            </div>                                                                                  
        </ui:repeat>
    </h:panelGroup>                              

</h:body>

Everything works except the inputText component. After ui-repeater is updated with Ajax is still displays the text from the previous string. For example, assume that initially i have a list with 2 strings, "val1" and "val2". I enter a new string called "val3" and submit the form. List is updated correctly on the server side and the repeater is updated, it now has 3 elements. However, while the h:outputText in the newly added element will correctly show "val3", the inputText will be displayed with "val2" as a value. So i end up with something looking like this:

output tag     input tag
val1           val1
val2           val2
val3           val2 (???)

The backing beans are very simple: A view scoped model bean

@Component
@Scope("view")
public class StringModel {

    private List<String> strings = Lists.newArrayList("Value 1");

    public List<String> getStrings() {
        return strings;
    }

    public void setStrings(List<String> strings) {
        this.strings = strings;
    }   
}

And a request scoped controller bean:

@Component
@Scope("request")
public class TestController {

    private String newString;
    @Autowired private StringModel model;

    public void addString() {
        model.getStrings().add(newString);
    }

    public String getNewString() {
        return newString;
    }

    public void setNewString(String newString) {
        this.newString = newString;
    }   

}

I did some testing and this actually works the same way for any input component, be that textInput, textArea, etc. Any help would be highly appreciated.

回答1:

I can't tell in detail exactly why it displays the wrong value after update (it'll be that the internal loop index of <ui:repeat> is broken — try a newer Mojarra version), but just referencing the string item by index from varStatus works. It'll also immediately fix the future problem of being unable to submit the edited string value when you put this list in a form, because the String class is immutable and doesn't have a setter.

<ui:repeat value="#{stringModel.strings}" var="str" varStatus="loop">
    <div>
        <h:outputText value="#{str}" />
        <h:inputText value="#{stringModel.strings[loop.index]}" />
    </div>
</ui:repeat>

回答2:

EditableValueHolders inside ui:repeat are broken (by design) in the current version o JSF specs. It will not work, there is no way to fix it. Maybe new versions will make ui:repeat a proper component with support for saving states of its children. Maybe not.

If you change ui:repeat to h:dataTable, things should work (if not, then your problem is somewhere else and I was wrong).

Frankly, there is no workaround apart from using repeaters from some other libraries - you should find working repeaters in Tomahawk, Trinidad and many other places. Primefaces, AFAIR, does not have a pure repeater.

回答3:

I also had exactly the same problem before. I solved it by putting the inputText in a form. I also copied your codes and put the h:inputText inside a h:form and it worked as well.

<h:form>
    <ui:repeat value="#{stringModel.strings}" var="str" varStatus="loop">
        <div>
            <h:outputText value="#{str}" />
            <h:inputText value="#{str}" />
        </div>
    </ui:repeat>
</h:form>