InfoPath with SharePoint 2010 : Dynamically Populate a Repeating Table - Clear Previous Entries

1. Clear Previous Entries

If you preview the form at this point, you will notice that every time you select a value from the selection drop-down, the repeating table is populated with more and more entries (along with a blank row at the top). You therefore need to clear any previous entries before the repeating table is populated. Place the code listed in Listing 1 somewhere before the while loop.

Listing 1. Clear Previous Entries

//Clear previous entries
XPathNavigator rTable = MainDataSource.CreateNavigator();
XPathNodeIterator tableRows =
rTable.Select("/my:myFields/my:group1/my:groupRepeat",
NamespaceManager);
if (tableRows.Count > 0)
{

   for (int i = tableRows.Count; i > 0; i--)
  {
     XPathNavigator reTable = MainDataSource.CreateNavigator();
     XPathNavigator reTableRows =
reTable.SelectSingleNode("/my:myFields/my:group1/my:groupRepeat[" + i
 + "]", NamespaceManager);
     reTableRows.DeleteSelf();
   }
}

2. What Does the Final Solution Look Like?

When all the code has been entered into the method properly, previewing the form populates the repeating table based on the selection in the drop-down, as shown in Figure 1.

Figure 1. Changing the selection populates the repeating table.

Listing 2 shows the full code listing for the changed method.

Listing 2. Fully Changed Method

public void selection_Changed(object sender, XmlEventArgs e)
        {

            //Namespace variable
            string myNamespace = NamespaceManager.LookupNamespace("my");

            //Clear previous entries
            XPathNavigator rTable = MainDataSource.CreateNavigator();
     XPathNodeIterator tableRows =
rTable.Select("/my:myFields/my:group1/my:groupRepeat",
NamespaceManager);
            if (tableRows.Count > 0)
            {


                for (int i = tableRows.Count; i > 0; i--)
                {
                    XPathNavigator reTable =
                    MainDataSource.CreateNavigator();
                    XPathNavigator reTableRows =

                    reTable.SelectSingleNode
("/my:myFields/my:group1/my:groupRepeat[" + i + "]",
NamespaceManager);
                    reTableRows.DeleteSelf();
                }
            }

            //Secondary data source setup
            DataSource ds = DataSources["Offices"];
            XPathNavigator domNav = ds.CreateNavigator();
            XPathNodeIterator rows = domNav.Select("/dfs:myFields/
dfs:dataFields/d:SharePointListItem_RW", NamespaceManager);


            //Loop through the secondary data source
            while (rows.MoveNext())
            {
                string office =
rows.Current.SelectSingleNode("d:Title",
NamespaceManager).Value.ToString();
                string region = rows.Current.SelectSingleNode("d:Region",
NamespaceManager).Value.ToString();
                string id =
rows.Current.SelectSingleNode("d:ID",
NamespaceManager).Value.ToString();

             //Populate the repeating table
             using (XmlWriter writer =

MainDataource.CreateNavigator().SelectSingleNode("/my:myFields/
my:group1", NamespaceManager).AppendChild())
        {
           writer.WriteStartElement("groupRepeat", myNamespace);
           writer.WriteElementString("field1", myNamespace, office);
           writer.WriteElementString("field2", myNamespace, region);
           writer.WriteElementString("field3", myNamespace, id);
           writer.WriteEndElement();
           writer.Close();
        }

            }

        }