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问题:

I have a Primefaces project with the following xhtml file:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:p="http://primefaces.org/ui">
  <h:body>
     <ui:composition>       
        <h:form>
            <p:dataTable id="parameters" var="parameter" value="#{devTestController.parameters}" 
                editable="true" editMode="cell" widgetVar="parameterTable" 
                selection="#{devTestController.selectedRow}" selectionMode="single"
                rowKey="#{parameter}">  

                <f:facet name="header">
                    Parameters
                </f:facet>

                <p:column headerText="Parameter Name" style="width:30%">  
                    <p:cellEditor>  
                        <f:facet name="output"><h:outputText value="#{parameter.label}" /></f:facet>  
                        <f:facet name="input"><p:inputText id="parameterNameInput" value="#{parameter.label}" style="width:96%"/></f:facet>  
                    </p:cellEditor>  
                </p:column>  

                <p:column headerText="Parameter Value" style="width:60%">  
                    <p:cellEditor>  
                        <f:facet name="output"><h:outputText value="#{parameter.value}" /></f:facet>  
                        <f:facet name="input"><p:inputText value="#{parameter.value}" style="width:96%" label="Parameter Value"/></f:facet>
                    </p:cellEditor>  
                </p:column>

                <p:column headerText="Action" style="width:10%">
                    <p:commandButton value="Button in table" action="#{devTestController.doAction()}"/>  
                </p:column>
            </p:dataTable>  
            <p:commandButton value="Button outside table" action="#{devTestController.doAction()}"/>
        </h:form>
        <p:commandButton value="Button outside form" action="#{devTestController.doAction()}"/>
      </ui:composition>     
   </h:body>
</html>

Here I have 3 commandButtons (p:commandButton). One is inside the dataTable (iterating component), one is outside the dataTable and one is outside h:form. Surprisingly, the only one working is the one outside the h:form (the last one). I've been searching the internet for 5 hours and already tried many things. I don't understand why this is happening. I read many posts regarding similar problems, but none of them solved my case. A pretty good one is this by BalusC. I have read all the cases and I can't find an answer. First I suspected that I have nested multiple UIForm components in each other (case 2) and I searched in the original xhtml file that includes the one above, but this is not the case. I have no other h:form tags in my code except this one. After all, if I completely remove the h:form tag, then no commandButton works and I also get the "The form component needs to have a UIForm in its ancestry. Suggestion: enclose the necessary components within h:form" warning. What could go wrong here?

回答1:

As @Omar points, you forgot that closing tag, even I suppose it's a mistyping when posting the question. Appart from that, I've tested by my own and it works for me (Primefaces 3.5, Mojarra JSF 2.1.26). I made this SSCCE, which is fully functional (buttons inside form work, not the one outside).

@ManagedBean
@RequestScoped
public class DevTestController {

    public class Parameter {
        private String label;

        private String value;

        public Parameter(String label, String value) {
            this.label = label;
            this.value = value;
        }

        public String getLabel() {
            return label;
        }

        public String getValue() {
            return value;
        }

        public void setLabel(String label) {
            this.label = label;
        }

        public void setValue(String value) {
            this.value = value;
        }
    }

    private Parameter selectedRow;

    private List<Parameter> parameters = Arrays.asList(new Parameter("param1",
            "p1"), new Parameter("param2", "p2"));

    public DevTestController() {

    }

    public void doAction() {
        System.out.println("Done");
    }

    public List<Parameter> getParameters() {
        return parameters;
    }

    public Parameter getSelectedRow() {
        return selectedRow;
    }

    public void setSelectedRow(Parameter selectedRow) {
        this.selectedRow = selectedRow;
    }

}

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:p="http://primefaces.org/ui">
<h:body>
        <h:form>
            <p:dataTable id="parameters" var="parameter"
                value="#{devTestController.parameters}" editable="true"
                editMode="cell" widgetVar="parameterTable"
                selection="#{devTestController.selectedRow}" selectionMode="single"
                rowKey="#{parameter}">

                <f:facet name="header">
                    Parameters
                </f:facet>

                <p:column headerText="Parameter Name" style="width:30%">
                    <p:cellEditor>
                        <f:facet name="output">
                            <h:outputText value="#{parameter.label}" />
                        </f:facet>
                        <f:facet name="input">
                            <p:inputText id="parameterNameInput" value="#{parameter.label}"
                                style="width:96%" />
                        </f:facet>
                    </p:cellEditor>
                </p:column>

                <p:column headerText="Parameter Value" style="width:60%">
                    <p:cellEditor>
                        <f:facet name="output">
                            <h:outputText value="#{parameter.value}" />
                        </f:facet>
                        <f:facet name="input">
                            <p:inputText value="#{parameter.value}" style="width:96%"
                                label="Parameter Value" />
                        </f:facet>
                    </p:cellEditor>
                </p:column>

                <p:column headerText="Action" style="width:10%">
                    <p:commandButton value="Button in table"
                        action="#{devTestController.doAction()}" />
                </p:column>
            </p:dataTable>
            <p:commandButton value="Button outside table"
                action="#{devTestController.doAction()}" />
        </h:form>
        <p:commandButton value="Button outside form"
            action="#{devTestController.doAction()}" />
</h:body>
</html>