6 Replies Latest reply on Jun 3, 2009 3:27 PM by Ahmet Guven

    picklist conversion problem

    Ahmet Guven Newbie

      hello,
      I am new in jsf. for the last 2 weeks, I have been trying to solve a problem (which is I guess an easy one for most experienced developers) with rich:pickList (I am using it for the first time). I made a search on internet and found the sample code below. I exactly applied it to my object class. I can get my objects listed their names on the left side of picklist. but when I select an item, rich:messages reports "conversion error" and does not save my values. I can not find any solution to my problem and I almost give up. Please help me.... thanks...

      <rich :p ickList value="#{yourBean.pickListResult}"
      copyAllControlLabel="add all"
      removeAllControlLabel="remove all"
      copyControlLabel="add"
      removeControlLabel="remove"
      converter="#{yourBean.converter}">
      <f:selectItems value="#{yourBean.leftPickList}" />
      <a4j:support event="onlistchanged"
      action="#{yourBean.updateSelection}" reRender="whatever"/>
      </rich :p ickList>

      public class YourBean {

      private boolean firstFill = true;

      //the two PickLists
      private List leftPickList = new ArrayList();
      private List<Your_Database_Object> pickListResult = new ArrayList<Your_Database_Object>();

      //Converting from SelectItems to your Object:
      private YourConverter converter;

      //rendering the dataTable depends on pickListResult.size()>0
      public boolean isResultListFilled() {
      if(firstFill)
      preload();
      if(this.pickListResult.size()>0)
      return true;
      else
      return false;
      }

      private void preload() {
      for(Your_Database_Object a: getPreselectionListFromDB()){
      pickListResult.add(a);
      }
      }

      public List getLeftPickList() {
      this.leftPickList = new ArrayList();

      //this list collects all items for the converter
      List<Your_Database_Object> tmpList = new ArrayList<Your_Database_Object>();

      //adding result items to the list to be added to the converter
      for(Your_Database_Object x: this.pickListResult)
      tmpList.add(x);

      for(Your_Database_Object a: getAvailableSelectionListFromDatabase()){
      tmpList.add(a);
      }

      //creates the converter on first load with all possible items including result items
      if(firstFill)
      converter = new YourConverter(tmpList);
      firstFill = false;

      //adding all items to the SelectItem-list
      for(Your_Database_Object a: tmpList){
      SelectItem s = new SelectItem(a,a.getYourObjectName());
      this.leftPickList.add(s);
      }
      return leftPickList;
      }

      //other important Getters and Setters

      public YourConverter getConverter() {
      return converter;
      }

      public void setConverter(YourConverter con) {
      this.converter = con;
      }

      public void setPickListResult(List<Your_Database_Object> pickListResult) {
      this.pickListResult = pickListResult;
      }

      public List<Your_Database_Object> getPickListResult() {
      return pickListResult;
      }

      ... other methods
      }

      class YourConverter implements Converter{

      //converter uses a HashMap for switching from selectItems to your objects
      private HashMap<String, Your_Database_Object> map;

      public YourConverter(List<Your_Database_Object> objekts) {
      map=new HashMap<String, Your_Database_Object>();
      for(Your_Database_Object o :o bjekts){
      map.put(Integer.toString(o.getYourObjectID()), o);
      }
      }

      public Object getAsObject(FacesContext arg0, UIComponent arg1, String string) {
      return map.get(string);
      }

      public String getAsString(FacesContext arg0, UIComponent arg1, Object obj) {
      if(obj instanceof Your_Database_Object)
      return Integer.toString(((Your_Database_Object)obj).getYourObjectID());
      return null;
      }
      }