/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package javax.faces.component;
  
  import java.io.IOException;
  import java.sql.ResultSet;
  import java.util.*;
  import javax.el.ValueExpression;
  import javax.faces.FacesException;
  import javax.faces.application.FacesMessage;
  import javax.faces.context.FacesContext;
  import javax.faces.event.AbortProcessingException;
  import javax.faces.event.FacesEvent;
  import javax.faces.event.FacesListener;
  import javax.faces.event.PhaseId;
  import javax.faces.model.*;
  import javax.servlet.jsp.jstl.sql.Result;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFComponent;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFacet;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFProperty;
  
  /**
   * Represents an abstraction of a component which has multiple "rows" of data.
   * <p>
   * The children of this component are expected to be UIColumn components.
   * <p>
   * Note that the same set of child components are reused to implement each row of the table in turn during
   * such phases as apply-request-values and render-response. Altering any of the members of these components
   * therefore affects the attribute for every row, except for the following members:
   * <ul>
   * <li>submittedValue
   * <li>value (where no EL binding is used)
   * <li>valid
   * </ul>
   * <p>
   * This reuse of the child components also means that it is not possible to save a reference to a component
   * during table processing, then access it later and expect it to still represent the same row of the table.
   * <h1>
   * Implementation Notes
   * </h1>
   * <p>
   * Each of the UIColumn children of this component has a few component children of its own to render the contents
   * of the table cell. However there can be a very large number of rows in a table, so it isn't efficient for the
   * UIColumn and all its child objects to be duplicated for each row in the table. Instead the "flyweight" pattern
   * is used where a serialized state is held for each row. When setRowIndex is invoked, the UIColumn objects and
   * their children serialize their current state then reinitialise themselves from the appropriate saved state.
   * This allows a single set of real objects to represent multiple objects which have the same types but potentially
   * different internal state. When a row is selected for the first time, its state is set to a clean "initial" state.
   * Transient components (including any read-only component) do not save their state; they are just reinitialised as
   * required. The state saved/restored when changing rows is not the complete component state, just the fields that
   * are expected to vary between rows: "submittedValue", "value", "isValid".
   * </p>
   * <p>
   * Note that a table is a "naming container", so that components within the table have their ids prefixed with the
   * id of the table. Actually, when setRowIndex has been called on a table with id of "zzz" the table pretends to
   * its children that its ID is "zzz_n" where n is the row index. This means that renderers for child components which
   * call component.getClientId automatically get ids of form "zzz_n:childId" thus ensuring that components in
   * different rows of the table get different ids.
   * </p>
   * <p>
   * When decoding a submitted page, this class iterates over all its possible rowIndex values, restoring the
   * appropriate serialized row state then calling processDecodes on the child components. Because the child
   * components (or their renderers) use getClientId to get the request key to look for parameter data, and because
   * this object pretends to have a different id per row ("zzz_n") a single child component can decode data from each
   * table row in turn without being aware that it is within a table. The table's data model is updated before each
   * call to child.processDecodes, so the child decode method can assume that the data model's rowData points to the
   * model object associated with the row currently being decoded. Exactly the same process applies for the later
   * validation and updateModel phases.
   * </p>
   * <p>
   * When the data model for the table is bound to a backing bean property, and no validation errors have occured
   * during processing of a postback, the data model is refetched at the start of the rendering phase (ie after the
   * update model phase) so that the contents of the data model can be changed as a result of the latest form
   * submission. Because the saved row state must correspond to the elements within the data model, the row state
   * must be discarded whenever a new data model is fetched; not doing this would cause all sorts of inconsistency
   * issues. This does imply that changing the state of any of the members "submittedValue", "value" or "valid" of
   * a component within the table during the invokeApplication phase has no effect on the rendering of the table.
   * When a validation error has occurred, a new DataModel is <i>not</i> fetched, and the saved state of the child
   * components is <i>not</i> discarded.
   * </p>
   * see Javadoc of the <a href="http://java.sun.com/j2ee/javaserverfaces/1.2/docs/api/index.html">JSF Specification</a>
   * for more information.
   *
  * @author Manfred Geiler (latest modification by $Author: lu4242 $)
  * @version $Revision: 1203044 $ $Date: 2011-11-16 23:22:07 -0500 (Wed, 16 Nov 2011) $
  */
 @JSFComponent(defaultRendererType = "javax.faces.Table")
 public class UIData extends UIComponentBase
                     implements NamingContainer
 {
     public static final String COMPONENT_FAMILY = "javax.faces.Data";
     public static final String COMPONENT_TYPE = "javax.faces.Data"; // for unit tests
 
     private static final String FOOTER_FACET_NAME = "footer";
     private static final String HEADER_FACET_NAME = "header";
     private static final Class OBJECT_ARRAY_CLASS = (new Object[0]).getClass();
     private static final int PROCESS_DECODES = 1;
     private static final int PROCESS_VALIDATORS = 2;
     private static final int PROCESS_UPDATES = 3;
 
     private static final Object[] LEAF_NO_STATE = new Object[]{null,null};
 
     private int _rowIndex = -1;
     private String _var;
 
     // Holds for each row the states of the child components of this UIData.
     // Note that only "partial" component state is saved: the component fields
     // that are expected to vary between rows.
     private Map _rowStates = new HashMap();
 
     /**
      * Handle case where this table is nested inside another table.
      * See method getDataModel for more details.
      * <p>
      * Key: parentClientId (aka rowId when nested within a parent table)
      * Value: DataModel
      */
     private Map _dataModelMap = new HashMap();
 
     // will be set to false if the data should not be refreshed at the beginning of the encode phase
     private boolean _isValidChilds = true;
 
     private Object _initialDescendantComponentState = null;
 
     private int _first;
     private boolean _firstSet;
     private int _rows;
     private boolean _rowsSet;
     private Object _value;
 
     private static class FacesEventWrapper extends FacesEvent
     {
         private static final long serialVersionUID = 6648047974065628773L;
         private FacesEvent _wrappedFacesEvent;
         private int _rowIndex;
 
         public FacesEventWrapper(FacesEvent facesEvent, int rowIndex,
                 UIData redirectComponent)
         {
             super(redirectComponent);
             _wrappedFacesEvent = facesEvent;
             _rowIndex = rowIndex;
         }
 
         @Override
         public PhaseId getPhaseId()
         {
             return _wrappedFacesEvent.getPhaseId();
         }
 
         @Override
         public void setPhaseId(PhaseId phaseId)
         {
             _wrappedFacesEvent.setPhaseId(phaseId);
         }
 
         @Override
         public void queue()
         {
             _wrappedFacesEvent.queue();
         }
 
         @Override
         public String toString()
         {
             return _wrappedFacesEvent.toString();
         }
 
         @Override
         public boolean isAppropriateListener(FacesListener faceslistener)
         {
             return _wrappedFacesEvent.isAppropriateListener(faceslistener);
         }
 
         @Override
         public void processListener(FacesListener faceslistener)
         {
             _wrappedFacesEvent.processListener(faceslistener);
         }
 
         public FacesEvent getWrappedFacesEvent()
         {
             return _wrappedFacesEvent;
         }
 
         public int getRowIndex()
         {
             return _rowIndex;
         }
     }
 
 
     private static final DataModel EMPTY_DATA_MODEL = new DataModel()
     {
         @Override
         public boolean isRowAvailable()
         {
             return false;
         }
 
         @Override
         public int getRowCount()
         {
             return 0;
         }
 
         @Override
         public Object getRowData()
         {
             throw new IllegalArgumentException();
         }
 
         @Override
         public int getRowIndex()
         {
             return -1;
         }
 
         @Override
         public void setRowIndex(int i)
         {
             if (i < -1)
                 throw new IllegalArgumentException();
         }
 
         @Override
         public Object getWrappedData()
         {
             return null;
         }
 
         @Override
         public void setWrappedData(Object obj)
         {
             if (obj == null)
             {
                 return; //Clearing is allowed
             }
             throw new UnsupportedOperationException(this.getClass().getName()
                     + " UnsupportedOperationException");
         }
     };
 
     private class EditableValueHolderState
     {
         private final Object _value;
         private final boolean _localValueSet;
         private final boolean _valid;
         private final Object _submittedValue;
 
         public EditableValueHolderState(EditableValueHolder evh)
         {
             _value = evh.getLocalValue();
             _localValueSet = evh.isLocalValueSet();
             _valid = evh.isValid();
             _submittedValue = evh.getSubmittedValue();
         }
 
         public void restoreState(EditableValueHolder evh)
         {
             evh.setValue(_value);
             evh.setLocalValueSet(_localValueSet);
             evh.setValid(_valid);
             evh.setSubmittedValue(_submittedValue);
         }
     }
 
     /**
      * Construct an instance of the UIData.
      */
     public UIData()
     {
         setRendererType("javax.faces.Table");
     }
 
     @Override
     public boolean invokeOnComponent(FacesContext context, String clientId, ContextCallback callback) throws FacesException {
         if (context == null || clientId == null || callback == null)
         {
             throw new NullPointerException();
         }
 
         //searching for this component?
         boolean returnValue = this.getClientId(context).equals(clientId);
 
         boolean isCachedFacesContext = isCachedFacesContext();
         if (!isCachedFacesContext)
         {
             setCachedFacesContext(context);
         }
         
         try
         {
             if (returnValue)
             {
                 try
                 {
                     callback.invokeContextCallback(context, this);
                 }
                 catch (Exception e)
                 {
                     throw new FacesException(e);
                 }
                 return returnValue;
             }
     
             //Now Look throught facets on this UIComponent
             for (Iterator<UIComponent> it = this.getFacets().values().iterator(); !returnValue && it.hasNext();)
             {
                 returnValue = it.next().invokeOnComponent(context, clientId, callback);
             }
     
             if (returnValue == true)
             {
                 return returnValue;
             }
             
             //Now we have to check if it is searching an inner component
             String baseClientId = super.getClientId(context);
             
             // is the component an inner component?
             if (clientId.startsWith(baseClientId))
             {
                 // Check if the clientId for the component, which we 
                 // are looking for, has a rowIndex attached
                 String subId = clientId.substring(baseClientId.length() + 1);
                 //If the char next to baseClientId is the separator one and
                 //the subId matches the regular expression
                 if (clientId.charAt(baseClientId.length()) == NamingContainer.SEPARATOR_CHAR && 
                         subId.matches("[0-9]+"+NamingContainer.SEPARATOR_CHAR+".*"))
                 {
                     String clientRow = subId.substring(0, subId.indexOf(NamingContainer.SEPARATOR_CHAR));
         
                     //Now we save the current position
                     int oldRow = this.getRowIndex();
                     
                     // try-finally --> make sure, that the old row index is restored
                     try
                     {
                         //The conversion is safe, because its already checked on the
                         //regular expresion
                         this.setRowIndex(Integer.parseInt(clientRow));
                         
                         // check, if the row is available
                         if (!isRowAvailable())
                         {
                             return false;
                         }
             
                         for (Iterator<UIComponent> it1 = getChildren().iterator(); 
                                 !returnValue && it1.hasNext();)
                         {
                             //recursive call to find the component
                             returnValue = it1.next().invokeOnComponent(context, clientId, callback);
                         }
                     }
                     finally
                     {
                         //Restore the old position. Doing this prevent
                         //side effects.
                         this.setRowIndex(oldRow);
                     }
                 }
                 else
                 {
                     // MYFACES-2370: search the component in the childrens' facets too.
                     // We have to check the childrens' facets here, because in MyFaces
                     // the rowIndex is not attached to the clientId for the children of
                     // facets of the UIColumns. However, in RI the rowIndex is 
                     // attached to the clientId of UIColumns' Facets' children.
                     for (Iterator<UIComponent> itChildren = this.getChildren().iterator();
                             !returnValue && itChildren.hasNext();)
                     {
                         UIComponent child = itChildren.next();
                         if (child instanceof UIColumn && clientId.equals(child.getClientId(context)))
                         {
                             try {
                                 callback.invokeContextCallback(context, child);
                             } catch (Exception e) {
                                 throw new FacesException(e);
                             }
                             returnValue = true;
                         }
                         // process the child's facets
                         for (Iterator<UIComponent> itChildFacets = child.getFacets().values().iterator(); 
                                 !returnValue && itChildFacets.hasNext();)
                         {
                             //recursive call to find the component
                             returnValue = itChildFacets.next().invokeOnComponent(context, clientId, callback);
                         }
                     }
                 }
             }
         }
         finally
         {
             if (!isCachedFacesContext)
             {
                 setCachedFacesContext(null);
             }
         }
 
         return returnValue;
     }
 
     public void setFooter(UIComponent footer)
     {
         getFacets().put(FOOTER_FACET_NAME, footer);
     }
 
     @JSFFacet
     public UIComponent getFooter()
     {
         return (UIComponent) getFacets().get(FOOTER_FACET_NAME);
     }
 
     public void setHeader(UIComponent header)
     {
         getFacets().put(HEADER_FACET_NAME, header);
     }
 
     @JSFFacet
     public UIComponent getHeader()
     {
         return (UIComponent) getFacets().get(HEADER_FACET_NAME);
     }
 
     public boolean isRowAvailable()
     {
         return getDataModel().isRowAvailable();
     }
 
     public int getRowCount()
     {
         return getDataModel().getRowCount();
     }
 
     public Object getRowData()
     {
         return getDataModel().getRowData();
     }
 
     public int getRowIndex()
     {
         return _rowIndex;
     }
 
     /**
      * Set the current row index that methods like getRowData use.
      * <p>
      * Param rowIndex can be -1, meaning "no row".
      * <p>
      * 
      * @param rowIndex
      */
     public void setRowIndex(int rowIndex)
     {
         if (rowIndex < -1)
         {
             throw new IllegalArgumentException("rowIndex is less than -1");
         }
 
         if (_rowIndex == rowIndex)
         {
             return;
         }
 
         FacesContext facesContext = getFacesContext();
 
         if (_rowIndex == -1)
         {
             if (_initialDescendantComponentState == null)
             {
                 // Create a template that can be used to initialise any row
                 // that we haven't visited before, ie a "saved state" that can
                 // be pushed to the "restoreState" method of all the child
                 // components to set them up to represent a clean row.
                 _initialDescendantComponentState = saveDescendantComponentStates(this, false, false);
             }
         }
         else
         {
             // If no initial component state, there are no EditableValueHolder instances,
             // and that means there is no state to be saved for the current row, so we can
             // skip row state saving code safely.
             if (_initialDescendantComponentState != null)
             {
                 // We are currently positioned on some row, and are about to
                 // move off it, so save the (partial) state of the components
                 // representing the current row. Later if this row is revisited
                 // then we can restore this state.
                 Collection<Object[]> savedRowState = saveDescendantComponentStates(this, false, false);
                 if (savedRowState != null)
                 {
                     _rowStates.put(getClientId(facesContext), savedRowState);
                 }
             }
         }
 
         _rowIndex = rowIndex;
 
         DataModel dataModel = getDataModel();
         dataModel.setRowIndex(rowIndex);
 
         String var = _var;
         if (rowIndex == -1)
         {
             if (var != null)
             {
                 facesContext.getExternalContext().getRequestMap().remove(var);
             }
         }
         else
         {
             if (var != null)
             {
                 if (isRowAvailable())
                 {
                     Object rowData = dataModel.getRowData();
                     facesContext.getExternalContext().getRequestMap().put(var,
                             rowData);
                 }
                 else
                 {
                     facesContext.getExternalContext().getRequestMap().remove(
                             var);
                 }
             }
         }
 
         if (_rowIndex == -1)
         {
             // reset components to initial state
             // If no initial state, skip row restore state code
             if (_initialDescendantComponentState != null)
             {
                 restoreDescendantComponentStates(this, false, _initialDescendantComponentState, false);
             }
             else
             {
                 restoreDescendantComponentWithoutRestoreState(this, false, false);
             }
         }
         else
         {
             Object rowState = _rowStates.get(getClientId(facesContext));
             if (rowState == null)
             {
                 // We haven't been positioned on this row before, so just
                 // configure the child components of this component with
                 // the standard "initial" state
                 // If no initial state, skip row restore state code
                 if (_initialDescendantComponentState != null)
                 {
                     restoreDescendantComponentStates(this, false, _initialDescendantComponentState, false);
                 }
                 else
                 {
                     restoreDescendantComponentWithoutRestoreState(this, false, false);
                 }
             }
             else
             {
                 // We have been positioned on this row before, so configure
                 // the child components of this component with the (partial)
                 // state that was previously saved. Fields not in the
                 // partial saved state are left with their original values.
                 restoreDescendantComponentStates(this, false, rowState, false);
             }
         }
     }
 
     /**
      * Overwrite the state of the child components of this component with data previously saved by method
      * saveDescendantComponentStates.
      * <p>
      * The saved state info only covers those fields that are expected to vary between rows of a table. Other fields are
      * not modified.
      */
     @SuppressWarnings("unchecked")
     private void restoreDescendantComponentStates(UIComponent parent, boolean iterateFacets, Object state,
                                                   boolean restoreChildFacets)
     {
         int descendantStateIndex = -1;
         List<? extends Object[]> stateCollection = null;
         
         if (iterateFacets && parent.getFacetCount() > 0)
         {
             Iterator<UIComponent> childIterator = parent.getFacets().values().iterator();
             
             while (childIterator.hasNext())
             {
                 UIComponent component = childIterator.next();
 
                 // reset the client id (see spec 3.1.6)
                 component.setId(component.getId());
                 if (!component.isTransient())
                 {
                     if (descendantStateIndex == -1)
                     {
                         stateCollection = ((List<? extends Object[]>) state);
                         descendantStateIndex = stateCollection.isEmpty() ? -1 : 0;
                     }
                     
                     if (descendantStateIndex != -1 && descendantStateIndex < stateCollection.size())
                     {
                         Object[] object = stateCollection.get(descendantStateIndex);
                         if (object[0] != null && component instanceof EditableValueHolder)
                         {
                             ((EditableValueHolderState) object[0]).restoreState((EditableValueHolder) component);
                         }
                         // If there is descendant state to restore, call it recursively, otherwise
                         // it is safe to skip iteration.
                         if (object[1] != null)
                         {
                             restoreDescendantComponentStates(component, restoreChildFacets, object[1], true);
                         }
                         else
                         {
                             restoreDescendantComponentWithoutRestoreState(component, restoreChildFacets, true);
                         }
                     }
                     else
                     {
                         restoreDescendantComponentWithoutRestoreState(component, restoreChildFacets, true);
                     }
                     descendantStateIndex++;
                 }
             }
         }
         
         if (parent.getChildCount() > 0)
         {
             for (int i = 0; i < parent.getChildCount(); i++)
             {
                 UIComponent component = parent.getChildren().get(i);
 
                 // reset the client id (see spec 3.1.6)
                 component.setId(component.getId());
                 if (!component.isTransient())
                 {
                     if (descendantStateIndex == -1)
                     {
                         stateCollection = ((List<? extends Object[]>) state);
                         descendantStateIndex = stateCollection.isEmpty() ? -1 : 0;
                     }
                     
                     if (descendantStateIndex != -1 && descendantStateIndex < stateCollection.size())
                     {
                         Object[] object = stateCollection.get(descendantStateIndex);
                         if (object[0] != null && component instanceof EditableValueHolder)
                         {
                             ((EditableValueHolderState) object[0]).restoreState((EditableValueHolder) component);
                         }
                         // If there is descendant state to restore, call it recursively, otherwise
                         // it is safe to skip iteration.
                         if (object[1] != null)
                         {
                             restoreDescendantComponentStates(component, restoreChildFacets, object[1], true);
                         }
                         else
                         {
                             restoreDescendantComponentWithoutRestoreState(component, restoreChildFacets, true);
                         }
                     }
                     else
                     {
                         restoreDescendantComponentWithoutRestoreState(component, restoreChildFacets, true);
                     }
                     descendantStateIndex++;
                 }
             }
         }
     }
 
     /**
      * Just call component.setId(component.getId()) to reset all client ids and 
      * ensure they will be calculated for the current row, but do not waste time
      * dealing with row state code.
      * 
      * @param parent
      * @param iterateFacets
      * @param restoreChildFacets 
      */
     private void restoreDescendantComponentWithoutRestoreState(UIComponent parent, boolean iterateFacets, boolean restoreChildFacets)
     {
         if (iterateFacets && parent.getFacetCount() > 0)
         {
             Iterator<UIComponent> childIterator = parent.getFacets().values().iterator();
             
             while (childIterator.hasNext())
             {
                 UIComponent component = childIterator.next();
 
                 // reset the client id (see spec 3.1.6)
                 component.setId(component.getId());
                 if (!component.isTransient())
                 {
                     restoreDescendantComponentWithoutRestoreState(component, restoreChildFacets, true);
                 }
             }
         }
         
         if (parent.getChildCount() > 0)
         {
             for (int i = 0; i < parent.getChildCount(); i++)
             {
                 UIComponent component = parent.getChildren().get(i);
 
                 // reset the client id (see spec 3.1.6)
                 component.setId(component.getId());
                 if (!component.isTransient())
                 {
                     restoreDescendantComponentWithoutRestoreState(component, restoreChildFacets, true);
                 }
             }
         }
     }
 
     /**
      * Walk the tree of child components of this UIData, saving the parts of their state that can vary between rows.
      * <p>
      * This is very similar to the process that occurs for normal components when the view is serialized. Transient
      * components are skipped (no state is saved for them).
      * <p>
      * If there are no children then null is returned. If there are one or more children, and all children are transient
      * then an empty collection is returned; this will happen whenever a table contains only read-only components.
      * <p>
      * Otherwise a collection is returned which contains an object for every non-transient child component; that object
      * may itself contain a collection of the state of that child's child components.
      */
     private Collection<Object[]> saveDescendantComponentStates(UIComponent parent, boolean iterateFacets,
                                                                boolean saveChildFacets)
     {
         Collection<Object[]> childStates = null;
         // Index to indicate how many components has been passed without state to save.
         int childEmptyIndex = 0;
         int totalChildCount = 0;
                 
         if (iterateFacets && parent.getFacetCount() > 0)
         {
             Iterator<UIComponent> childIterator = parent.getFacets().values().iterator();
 
             while (childIterator.hasNext())
             {
                 UIComponent child = childIterator.next();
                 if (!child.isTransient())
                 {
                     // Add an entry to the collection, being an array of two
                     // elements. The first element is the state of the children
                     // of this component; the second is the state of the current
                     // child itself.
 
                     if (child instanceof EditableValueHolder)
                     {
                         if (childStates == null)
                         {
                             childStates = new ArrayList<Object[]>(
                                     parent.getFacetCount()
                                     + parent.getChildCount()
                                     - totalChildCount
                                     + childEmptyIndex);
                             for (int ci = 0; ci < childEmptyIndex; ci++)
                             {
                                 childStates.add(LEAF_NO_STATE);
                             }
                         }
                     
                         childStates.add(child.getChildCount() > 0 ? 
                                 new Object[]{new EditableValueHolderState((EditableValueHolder) child),
                                     saveDescendantComponentStates(child, saveChildFacets, true)} :
                                 new Object[]{new EditableValueHolderState((EditableValueHolder) child),
                                     null});
                     }
                     else if (child.getChildCount() > 0 || (saveChildFacets && child.getFacetCount() > 0))
                     {
                         Object descendantSavedState = saveDescendantComponentStates(child, saveChildFacets, true);
                         
                         if (descendantSavedState == null)
                         {
                             if (childStates == null)
                             {
                                 childEmptyIndex++;
                             }
                             else
                             {
                                 childStates.add(LEAF_NO_STATE);
                             }
                         }
                         else
                         {
                             if (childStates == null)
                             {
                                 childStates = new ArrayList<Object[]>(
                                         parent.getFacetCount()
                                         + parent.getChildCount()
                                         - totalChildCount
                                         + childEmptyIndex);
                                 for (int ci = 0; ci < childEmptyIndex; ci++)
                                 {
                                     childStates.add(LEAF_NO_STATE);
                                 }
                             }
                             childStates.add(new Object[]{null, descendantSavedState});
                         }
                     }
                     else
                     {
                         if (childStates == null)
                         {
                             childEmptyIndex++;
                         }
                         else
                         {
                             childStates.add(LEAF_NO_STATE);
                         }
                     }
                 }
                 totalChildCount++;
             }
         }
         
         if (parent.getChildCount() > 0)
         {
             for (int i = 0; i < parent.getChildCount(); i++)
             {
                 UIComponent child = parent.getChildren().get(i);
                 if (!child.isTransient())
                 {
                     // Add an entry to the collection, being an array of two
                     // elements. The first element is the state of the children
                     // of this component; the second is the state of the current
                     // child itself.
 
                     if (child instanceof EditableValueHolder)
                     {
                         if (childStates == null)
                         {
                             childStates = new ArrayList<Object[]>(
                                     parent.getFacetCount()
                                     + parent.getChildCount()
                                     - totalChildCount
                                     + childEmptyIndex);
                             for (int ci = 0; ci < childEmptyIndex; ci++)
                             {
                                 childStates.add(LEAF_NO_STATE);
                             }
                         }
                     
                         childStates.add(child.getChildCount() > 0 ? 
                                 new Object[]{new EditableValueHolderState((EditableValueHolder) child),
                                     saveDescendantComponentStates(child, saveChildFacets, true)} :
                                 new Object[]{new EditableValueHolderState((EditableValueHolder) child),
                                     null});
                     }
                     else if (child.getChildCount() > 0 || (saveChildFacets && child.getFacetCount() > 0))
                     {
                         Object descendantSavedState = saveDescendantComponentStates(child, saveChildFacets, true);
                         
                         if (descendantSavedState == null)
                         {
                             if (childStates == null)
                             {
                                 childEmptyIndex++;
                             }
                             else
                             {
                                 childStates.add(LEAF_NO_STATE);
                             }
                         }
                         else
                         {
                             if (childStates == null)
                             {
                                 childStates = new ArrayList<Object[]>(
                                         parent.getFacetCount()
                                         + parent.getChildCount()
                                         - totalChildCount
                                         + childEmptyIndex);
                                 for (int ci = 0; ci < childEmptyIndex; ci++)
                                 {
                                     childStates.add(LEAF_NO_STATE);
                                 }
                             }
                             childStates.add(new Object[]{null, descendantSavedState});
                         }
                     }
                     else
                     {
                         if (childStates == null)
                         {
                             childEmptyIndex++;
                         }
                         else
                         {
                             childStates.add(LEAF_NO_STATE);
                         }
                     }
                 }
                 totalChildCount++;
             }
         }
         
         return childStates;
     }
     
     @Override
     public void setValueExpression(String name, ValueExpression binding) {
         if (name == null)
         {
             throw new NullPointerException("name");
         }
         else if (name.equals("value"))
         {
             _dataModelMap.clear();
         }
         else if (name.equals("rowIndex"))
         {
             throw new IllegalArgumentException("name " + name);
         }
         super.setValueExpression(name, binding);
     }
 
     @Override
     public String getClientId(FacesContext context)
     {
         String clientId = super.getClientId(context);
         int rowIndex = getRowIndex();
         if (rowIndex == -1)
         {
             return clientId;
         }
 
         StringBuilder bld = __getSharedStringBuilder();
         return bld.append(clientId).append(NamingContainer.SEPARATOR_CHAR).append(rowIndex).toString();
     }
 
     /**
      * Modify events queued for any child components so that the
      * UIData state will be correctly configured before the event's
      * listeners are executed.
      * <p>
      * Child components or their renderers may register events against
      * those child components. When the listener for that event is
      * eventually invoked, it may expect the uidata's rowData and
      * rowIndex to be referring to the same object that caused the
      * event to fire.
      * <p>
      * The original queueEvent call against the child component has been
      * forwarded up the chain of ancestors in the standard way, making
      * it possible here to wrap the event in a new event whose source
      * is <i>this</i> component, not the original one. When the event
      * finally is executed, this component's broadcast method is invoked,
      * which ensures that the UIData is set to be at the correct row
      * before executing the original event.
      */
     @Override
     public void queueEvent(FacesEvent event)
     {
         super.queueEvent(new FacesEventWrapper(event, getRowIndex(), this));
     }
 
     /**
      * Ensure that before the event's listeners are invoked this UIData
      * component's "current row" is set to the row associated with the event.
      * <p>
      * See queueEvent for more details.
      */
     @Override
     public void broadcast(FacesEvent event) throws AbortProcessingException
     {
         if (event instanceof FacesEventWrapper)
         {
             FacesEvent originalEvent = ((FacesEventWrapper) event)
                     .getWrappedFacesEvent();
             int eventRowIndex = ((FacesEventWrapper) event).getRowIndex();
             int currentRowIndex = getRowIndex();
             setRowIndex(eventRowIndex);
             try
             {
               originalEvent.getComponent().broadcast(originalEvent);
             }
             finally
             {
               setRowIndex(currentRowIndex);
             }
         }
         else
         {
             super.broadcast(event);
         }
     }
 
     /**
      * Perform necessary actions when rendering of this component starts,
      * before delegating to the inherited implementation which calls the
      * associated renderer's encodeBegin method.
      */
     @Override
     public void encodeBegin(FacesContext context) throws IOException
     {
         _initialDescendantComponentState = null;
         if (_isValidChilds && !hasErrorMessages(context))
         {
             // Clear the data model so that when rendering code calls
             // getDataModel a fresh model is fetched from the backing
             // bean via the value-binding.
             _dataModelMap.clear();
 
             // When the data model is cleared it is also necessary to
             // clear the saved row state, as there is an implicit 1:1
             // relation between objects in the _rowStates and the
             // corresponding DataModel element.
             _rowStates.clear();
         }
         super.encodeBegin(context);
     }
 
     private boolean hasErrorMessages(FacesContext context)
     {
         for(Iterator iter = context.getMessages(); iter.hasNext();)
         {
             FacesMessage message = (FacesMessage) iter.next();
             if(FacesMessage.SEVERITY_ERROR.compareTo(message.getSeverity()) <= 0)
             {
                 return true;
             }
         }
         return false;
     }
 
     /**
      * @see javax.faces.component.UIComponentBase#encodeEnd(javax.faces.context.FacesContext)
      */
     @Override
     public void encodeEnd(FacesContext context) throws IOException
     {
         try
         {
             setCachedFacesContext(context);
             setRowIndex(-1);
         }
         finally
         {
             setCachedFacesContext(null);
         }
         super.encodeEnd(context);
     }
 
     @Override
     public void processDecodes(FacesContext context)
     {
         if (context == null)
         {
             throw new NullPointerException("context");
         }
         try
         {
             setCachedFacesContext(context);
             if (!isRendered())
             {
                 return;
             }
             setRowIndex(-1);
             processFacets(context, PROCESS_DECODES);
             processColumnFacets(context, PROCESS_DECODES);
             processColumnChildren(context, PROCESS_DECODES);
             setRowIndex(-1);
             try
             {
                 decode(context);
             }
             catch (RuntimeException e)
             {
                 context.renderResponse();
                 throw e;
             }
         }
         finally
         {
             setCachedFacesContext(null);
         }
     }
 
     @Override
     public void processValidators(FacesContext context)
     {
         if (context == null)
         {
             throw new NullPointerException("context");
         }
 
         try
         {
             setCachedFacesContext(context);
             if (!isRendered())
             {
                 return;
             }
     
             setRowIndex(-1);
             processFacets(context, PROCESS_VALIDATORS);
             processColumnFacets(context, PROCESS_VALIDATORS);
             processColumnChildren(context, PROCESS_VALIDATORS);
             setRowIndex(-1);
     
             // check if an validation error forces the render response for our data
             if (context.getRenderResponse())
             {
                 _isValidChilds = false;
             }
         }
         finally
         {
             setCachedFacesContext(null);
         }
     }
 
     @Override
     public void processUpdates(FacesContext context)
     {
         if (context == null)
         {
             throw new NullPointerException("context");
         }
         try
         {
             setCachedFacesContext(context);
             if (!isRendered())
             {
                 return;
             }
             setRowIndex(-1);
             processFacets(context, PROCESS_UPDATES);
             processColumnFacets(context, PROCESS_UPDATES);
             processColumnChildren(context, PROCESS_UPDATES);
             setRowIndex(-1);
     
             if (context.getRenderResponse())
             {
                 _isValidChilds = false;
             }
         }
         finally
         {
             setCachedFacesContext(null);
         }
     }
 
     private void processFacets(FacesContext context, int processAction)
     {
         for (Iterator it = getFacets().values().iterator(); it.hasNext();)
         {
             UIComponent facet = (UIComponent) it.next();
             process(context, facet, processAction);
         }
     }
 
     /**
      * Invoke the specified phase on all facets of all UIColumn children
      * of this component. Note that no methods are called on the UIColumn
      * child objects themselves.
      *
      * @param context is the current faces context.
      * @param processAction specifies a JSF phase: decode, validate or update.
      */
     private void processColumnFacets(FacesContext context, int processAction)
     {
         for (Iterator childIter = getChildren().iterator(); childIter.hasNext();)
         {
             UIComponent child = (UIComponent) childIter.next();
             if (child instanceof UIColumn)
             {
                 if (!child.isRendered())
                 {
                     //Column is not visible
                     continue;
                 }
                 for (Iterator facetsIter = child.getFacets().values()
                         .iterator(); facetsIter.hasNext();)
                 {
                     UIComponent facet = (UIComponent) facetsIter.next();
                     process(context, facet, processAction);
                 }
             }
         }
     }
 
     /**
      * Invoke the specified phase on all non-facet children of all UIColumn
      * children of this component. Note that no methods are called on the
      * UIColumn child objects themselves.
      *
      * @param context is the current faces context.
      * @param processAction specifies a JSF phase: decode, validate or update.
      */
     private void processColumnChildren(FacesContext context, int processAction)
     {
         int first = getFirst();
         int rows = getRows();
         int last;
         if (rows == 0)
         {
             last = getRowCount();
         }
         else
         {
             last = first + rows;
         }
         for (int rowIndex = first; last==-1 || rowIndex < last; rowIndex++)
         {
             setRowIndex(rowIndex);
 
             //scrolled past the last row
             if (!isRowAvailable())
             {
                 break;
             }
 
             for (Iterator it = getChildren().iterator(); it.hasNext();)
             {
                 UIComponent child = (UIComponent) it.next();
                 if (child instanceof UIColumn)
                 {
                     if (!child.isRendered())
                     {
                         //Column is not visible
                         continue;
                     }
                     for (Iterator columnChildIter = child.getChildren()
                             .iterator(); columnChildIter.hasNext();)
                     {
                         UIComponent columnChild = (UIComponent) columnChildIter
                                 .next();
                         process(context, columnChild, processAction);
                     }
                 }
             }
         }
     }
 
     private void process(FacesContext context, UIComponent component,
             int processAction)
     {
         switch (processAction)
         {
         case PROCESS_DECODES:
             component.processDecodes(context);
             break;
         case PROCESS_VALIDATORS:
             component.processValidators(context);
             break;
         case PROCESS_UPDATES:
             component.processUpdates(context);
             break;
         }
     }
 
     /**
      * Return the datamodel for this table, potentially fetching the data from
      * a backing bean via a value-binding if this is the first time this method
      * has been called.
      * <p>
      * This is complicated by the fact that this table may be nested within
      * another table. In this case a different datamodel should be fetched
      * for each row. When nested within a parent table, the parent reference
      * won't change but parent.getClientId() will, as the suffix changes
      * depending upon the current row index. A map object on this component
      * is therefore used to cache the datamodel for each row of the table.
      * In the normal case where this table is not nested inside a component
      * that changes its id (like a table does) then this map only ever has
      * one entry.
      */
     protected DataModel getDataModel()
     {
         DataModel dataModel;
         String clientID = "";
 
         UIComponent parent = getParent();
         if (parent != null)
         {
             clientID = parent.getClientId(getFacesContext());
         }
         dataModel = (DataModel) _dataModelMap.get(clientID);
         if (dataModel == null)
         {
             dataModel = createDataModel();
             _dataModelMap.put(clientID, dataModel);
         }
         return dataModel;
     }
 
     protected void setDataModel(DataModel dataModel)
     {
         throw new UnsupportedOperationException(
                 "this method is here only to maintain binary compatibility w/ the RI");
     }
 
     /**
      * Evaluate this object's value property and convert the result into a
      * DataModel. Normally this object's value property will be a value-binding
      * which will cause the value to be fetched from some backing bean.
      * <p>
      * The result of fetching the value may be a DataModel object, in which
      * case that object is returned directly. If the value is of type
      * List, Array, ResultSet, Result, other object or null then an appropriate
      * wrapper is created and returned.
      * <p>
      * Null is never returned by this method.
      */
     private DataModel createDataModel()
     {
         Object value = getValue();
 
         if (value == null)
         {
             return EMPTY_DATA_MODEL;
         }
         else if (value instanceof DataModel)
         {
             return (DataModel) value;
         }
         else if (value instanceof List)
         {
             return new ListDataModel((List) value);
         }
         else if (OBJECT_ARRAY_CLASS.isAssignableFrom(value.getClass()))
         {
             return new ArrayDataModel((Object[]) value);
         }
         else if (value instanceof ResultSet)
         {
             return new ResultSetDataModel((ResultSet) value);
         }
         else if (value instanceof Result)
         {
             return new ResultDataModel((Result) value);
         }
         else
         {
             return new ScalarDataModel(value);
         }
     }
 
     /**
      * An EL expression that specifies the data model that backs this table.
      * <p>
      * The value referenced by the EL expression can be of any type.
      * </p>
      * <ul>
      * <li>A value of type DataModel is used directly.</li>
      * <li>Array-like parameters of type array-of-Object, java.util.List, java.sql.ResultSet
      *  or javax.servlet.jsp.jstl.sql.Result are wrapped in a corresponding DataModel that
      *  knows how to iterate over the elements.</li>
      * <li>Other values are wrapped in a DataModel as a single row.</li>
      * </ul>
      * <p>
      * Note in particular that unordered collections, eg Set are not supported. Therefore if the
      * value expression references such an object then the table will be considered to contain just
      * one element - the collection itself.
      * </p>
      */
     @JSFProperty
     public Object getValue()
     {
       if (_value != null)
       {
         return _value;
       }
       ValueExpression expression = getValueExpression("value");
       if (expression != null)
       {
         return expression.getValue(getFacesContext().getELContext());
       }
       return null;
     }
 
     public void setValue(Object value)
     {
         _value = value;
         _dataModelMap.clear();
         _rowStates.clear();
         _isValidChilds = true;
     }
 
     /**
      * Defines the index of the first row to be displayed, starting from 0.
      */
     @JSFProperty
     public int getFirst()
     {
       if (_firstSet)
       {
         return _first;
       }
       ValueExpression expression = getValueExpression("first");
       if (expression != null)
       {
         return (Integer)expression.getValue(getFacesContext().getELContext());
       }
       return 0;
     }
 
     public void setFirst(int first)
     {
         if (first < 0)
         {
             throw new IllegalArgumentException("Illegal value for first row: " + first);
         }
         _first = first;
         _firstSet=true;
     }
 
     /**
      * Defines the maximum number of rows of data to be displayed.
      * <p>
      * Specify zero to display all rows from the "first" row to the end
      * of available data.
      * </p>
      */
     @JSFProperty
     public int getRows()
     {
       if (_rowsSet)
       {
         return _rows;
       }
       ValueExpression expression = getValueExpression("rows");
       if (expression != null)
       {
         return (Integer)expression.getValue(getFacesContext().getELContext());
       }
       return 0;
     }
 
     /**
      * Set the maximum number of rows displayed in the table.
      */
     public void setRows(int rows)
     {
         if (rows < 0)
         {
             throw new IllegalArgumentException("rows: " + rows);
         }
         _rows = rows;
         _rowsSet = true;
     }
 
   /**
    * Defines the name of the request-scope variable that will hold the current row during iteration.
    * <p>
    * During rendering of child components of this UIData, the variable with this name can be read to
    * learn what the "rowData" object for the row currently being rendered is.
    * </p>
    * <p>
    * This value must be a static value, ie an EL expression is not permitted.
    * </p>
    */
   @JSFProperty(literalOnly = true)
   public String getVar()
   {
     return _var;
   }
 
   public void setVar(String var)
   {
     this._var = var;
   }
 
 
   @Override
   public Object saveState(FacesContext facesContext)
   {
     Object[] values = new Object[7];
     values[0] = super.saveState(facesContext);
     values[1] = _value;
     values[2] = _var;
     values[3] = _rows;
     values[4] = _rowsSet;
     values[5] = _first;
     values[6] = _firstSet;
 
     return values;
   }
 
   @Override
   public void restoreState(FacesContext facesContext, Object state)
   {
     Object[] values = (Object[])state;
     super.restoreState(facesContext,values[0]);
     _value = values[1];
     _var = (String)values[2];
     _rows = (Integer)values[3];
     _rowsSet = (Boolean)values[4];
     _first = (Integer)values[5];
     _firstSet = (Boolean)values[6];
   }
 
   @Override
   public String getFamily()
   {
     return COMPONENT_FAMILY;
   }
 }