How to maintain/save row values when generating a new row?

i have the following bean:

public class MyBean {

public ArrayList<ReportRow> getReportRows()
    {
        return reportRows;
    }



    private final ArrayList<ReportRow> reportRows = 
        new ArrayList<ReportRow>(Arrays.asList(

                new ReportRow("","")
    ));

    public ArrayList<ReportRow> getOrderList() {

        return reportRows;

    }

    public String addAction() {

        ReportRow row = n开发者_运维问答ew ReportRow("", "");
        reportRows.add(row);
        return null;
    }



    public class ReportRow{

        String reportColumnName;
        String reportColumnDesc;

        public ReportRow(String reportColumnName,String reportColumnDesc) {

            this.reportColumnName=reportColumnName;
            this.reportColumnDesc=reportColumnDesc;
        }

        public String getReportColumnName()
        {
            return reportColumnName;
        }

        public void setReportColumnName(String reportColumnName)
        {
            this.reportColumnName = reportColumnName;
        }

        public String getReportColumnDesc()
        {
            return reportColumnDesc;
        }

        public void setReportColumnDesc(String reportColumnDesc)
        {
            this.reportColumnDesc = reportColumnDesc;
        }

    }

}

jsf page:

<t:dataTable value="#{myBean.reportRows}" var="o"
            id="reportColumnsTable" styleClass="standardTable" headerClass="standardTable_Header"
            rowStyleClass="#{myBean.viewDelayedRsd}"
            >

            <h:column>

            <t:outputLabel value="Column name:"></t:outputLabel>
            <t:inputText id="ReportColumnName" value="#{o.reportColumnName}" required="true">
            </t:inputText>

            </h:column>

            <h:column>

            <t:outputLabel value="Column Desc:"></t:outputLabel>
            <t:inputText id="ReportColumnDesc" value="#{o.reportColumnDesc}" >

            </t:inputText>

            </h:column>

            <h:column>

            <h:outputLink value="#add"><h:outputText value="Add"/>
                        <a4j:support ajaxSingle="true" event="onclick" action="#{rprtBean.addAction}"
                        reRender="reportColumnsTable,msgPanel" />                       
            </h:outputLink>

            </h:column>

            </t:dataTable>

problem is that when i click on add, it generates a new row, and clear the old one, and i want to maintain the values of old row, any ideas ?

You're using a <h:outputLink> instead of a <h:commandLink>. The <h:outputLink> doesn't submit the form at all, it fires a plain GET request. The <a4j:support> won't work properly inside a <h:outputLink>. Replace it by a <h:commandLink>:

<h:commandLink value="Add" action="#{rprtBean.addAction}">
    <a4j:support reRender="reportColumnsTable,msgPanel" ajaxSingle="true" />
</h:commandLink>

Then, you need to ensure that you preserve the data model for subsequent request in case that your bean is request scoped. There are several ways to achieve this:

1. Set either Tomahawk datatable's preserveDataModel to true:

   <t:dataTable preserveDataModel="true">
   

2. Or save the bean state in the view scope. Add the following tag somewhere in the page:

   <t:saveState value="#{myBean}" />
   

   or since you're also using RichFaces/Ajax4jsf:

   <a4j:keepAlive beanName="myBean" />
   

i just used the a4j command link and everything worked fine.