How to preserve table selections in bc4j?

Question

In a bc4j table with multiple selection, how do I preserve the selections when I navigate the table back and forth? I see examples, which show do-it-yourself data-bound table but not for bc4j.

Answer 1

I did something similar, but my table was in a template. Here is a snippet of my code:
   * handleSelections
   * Keeps track of the rows that the user has selected from one
   * page to the next.
  private static void _handleSelections(
    BajaContext bc,
    Page page,
    PageEvent event)
    // Get the TableState from the session (the TableState keeps track
    // of the blockSize, and the startIndex)
    // the key to get the TableState from the session is the table name   
    HttpSession sess = bc.getServletRequest().getSession();
    TableState tState = (LovTableState) sess.getAttribute(_TABLE_NAME);
    if (tState == null)
      bc.getErrorLog().logMessage("Table state is null.");
      return;
    String selName = PageEventFlattenedDataSet.getFlattenedName(_TABLE_NAME,
                                                                "selectMode");
    String selParam = event.getParameter(selName);
    // get the selections for the visible table rows.
    Boolean[] selections = tState.getSelections(); // tState has selections which is a Boolean array, the length of the table Data.
    if ( (selParam != null) &&
         ("none".equals(selParam) || "all".equals(selParam)) )
      Boolean val = new Boolean("all".equals(selParam));
      tState.setAllSelections(val);
    else
      DataSet tableInputs = new PageEventFlattenedDataSet(event,
                                                          _TABLE_NAME);
      int sz = tableInputs.getLength();
      int startRowIndex = tState.getStartIndex() - 1;
      int endRowIndex = sz + startRowIndex;
      // loop through the visible table rows.
      for (int i=0; i < sz; i++)
        // get the DataObject representing all the input elements
        // on the current table row.
        DataObject row = tableInputs.getItem(i);
        // Check if this row was selected
        Object value = row.selectValue(null, "selected");
        // Record the state of the selection of this row.
        Boolean val = ((value == null)
                    ? Boolean.FALSE
                    : Boolean.TRUE);
        tState.setSelections( (startRowIndex + i), val);
      return;
  }and a snippet of the uit file:
<tableSelection>
<multipleSelection data:selected="." data:selection="selections@tableState@data:rootAttr"/>
</tableSelection>
I'll try to take a closer look at your code to see what you might be doing wrong, but hopefully my code snippet will help.