/*
 * 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 $Author$)
 * @version $Revision$ $Date$
 */
@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;
  }
}