/**
* License Agreement.
*
* Rich Faces - Natural Ajax for Java Server Faces (JSF)
*
* Copyright (C) 2007 Exadel, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* ColumnsHandler.java Date created: 07.12.2007
* Last modified by: $Author$
* $Revision$ $Date$
*/
package org.richfaces.taglib;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.el.ELException;
import javax.el.ValueExpression;
import javax.el.VariableMapper;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.servlet.jsp.JspTagException;
import org.richfaces.component.UIColumn;
import org.richfaces.el.ELBuilder;
import org.richfaces.iterator.ForEachIterator;
import org.richfaces.iterator.SimpleForEachIterator;
import com.sun.facelets.FaceletContext;
import com.sun.facelets.tag.MetaRule;
import com.sun.facelets.tag.MetaRuleset;
import com.sun.facelets.tag.MetaTagHandler;
import com.sun.facelets.tag.Metadata;
import com.sun.facelets.tag.MetadataTarget;
import com.sun.facelets.tag.TagAttribute;
import com.sun.facelets.tag.jsf.ComponentConfig;
/**
* TODO Class description goes here.
*
* @author "Andrey Markavtsov"
*
*/
public class ColumnsHandler extends MetaTagHandler {
com.sun.facelets.tag.jsf.ComponentHandler handler;
static final String DYNAMIC_COLUMN_MARKER = "_richfaces_columns";
/** value attribute */
private TagAttribute value;
/** end attribute */
private TagAttribute columns;
/** begin attribute */
private TagAttribute begin;
/** var attribute */
private TagAttribute var;
/** index attribute */
private TagAttribute index;
/** end attribute */
private TagAttribute end;
/** rendered attribute */
private boolean rendered = true;
class IterationContext {
/** Iterator for columns's tag value attribute */
public ForEachIterator items; // our 'digested' items
/** Value attribute value */
public Object rawItems; // our 'raw' items
/** Var attr - defines page variable for current item */
public String _indexId;
/** Integer value begin attr */
public Integer _begin;
/** Integer value end attr */
public Integer _end;
/** Integer value of end attr. */
public Integer _columns;
/** String value of var attr */
public String _itemId = null;
/** Current column counter */
public Integer _index = 0;
/** Expression for var item */
public IteratedExpression iteratedExpression;
public String valueExpr;
public String getVarReplacement() {
if (valueExpr == null) {
return String.valueOf(index);
}else if (items.getVarReplacement() != null) {
return items.getVarReplacement();
}
return valueExpr + "[" + _index + "]";
}
public String getIndexReplacement() {
return String.valueOf(_index);
}
};
ThreadLocal<IterationContext> iterationContextLocal = new ThreadLocal<IterationContext>();
public IterationContext getIterationContext() {
return iterationContextLocal.get();
}
/**
* TODO Description goes here.
*
* @param config
*/
public ColumnsHandler(ComponentConfig config) {
super(config);
handler = new ColumnTagHandler(config) {
@Override
protected MetaRuleset createMetaRuleset(Class type) {
MetaRuleset ruleset = super.createMetaRuleset(type);
ruleset.addRule(new MetaRule() {
@Override
public Metadata applyRule(final String name,
final TagAttribute attribute, MetadataTarget meta) {
if (ColumnsAttributes.FILTER_ATTRIBUTES.indexOf(name) != -1) {
return new Metadata() {
@Override
public void applyMetadata(FaceletContext ctx,
Object instance) {
if (!attribute.isLiteral()) {
String expr = attribute.getValue();
IterationContext itContext = iterationContextLocal.get();
ValueExpression ve = ELBuilder.createValueExpression(expr, Object.class, ctx.getExpressionFactory(), ctx.getFacesContext().getELContext(),
itContext._itemId, itContext._indexId,
itContext.getVarReplacement(), itContext.getIndexReplacement());
((UIComponent)instance).setValueExpression(name, ve);
}else {
((UIComponent)instance).getAttributes().put(name, attribute.getValue());
}
}
};
}
return null;
}
});
return ruleset;
}
@Override
protected void applyNextHandler(FaceletContext ctx, UIComponent c)
throws IOException, FacesException, ELException {
c.getAttributes().put(DYNAMIC_COLUMN_MARKER, Boolean.TRUE);
super.applyNextHandler(ctx, c);
}
};
}
/**
* Extracts tags attributes values
*/
private void initVariables(FaceletContext ctx) {
initColumnsCount(ctx);
initIndex(ctx);
initVar(ctx);
initBegin(ctx);
initEnd(ctx);
}
/**
* Method prepares all we need for starting of tag rendering
*
* @throws JspTagException
*/
private void prepare(FaceletContext ctx) {
initVariables(ctx);
IterationContext itContext = getIterationContext();
try {
this.value = getAttribute("value");
itContext.valueExpr = ELBuilder.getVarReplacement(this.value.getValue());
// produce the right sort of ForEachIterator
if (value != null) {
// If this is a deferred expression, make a note and get
// the 'items' instance.
itContext.rawItems = value.getObject(ctx);
// extract an iterator over the 'items' we've got
itContext.items = SimpleForEachIterator
.supportedTypeForEachIterator(itContext.rawItems);
} else {
// no 'items', so use 'begin' and 'end'
itContext.items = SimpleForEachIterator
.beginEndForEachIterator(itContext._columns - 1);
}
} catch (Exception e) {
// TODO: handle exception
}
correctFirst(ctx);
}
/**
* Inits first iteration item
*/
private void correctFirst(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
if (itContext.items != null) {
if (itContext._begin > 0 && (itContext._index < itContext._begin)) {
while ((itContext._index < itContext._begin && hasNext())) {
next(ctx);
}
if (!hasNext()) {
itContext._index = 0;
}
}
}
}
/**
* Return true if we didn't complete column's count
*
* @return
* @throws JspTagException
*/
private boolean hasNext() {
IterationContext itContext = getIterationContext();
try {
if (itContext._end != 0) {
return (itContext._index < itContext._end) ? itContext.items.hasNext() : false;
} else {
return itContext.items.hasNext();
}
} catch (Exception e) {
return false;
}
}
/**
* Iterate to next column
*
* @return
* @throws JspTagException
*/
private Object next(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
try {
Object o = itContext.items.next();
itContext._index++;
return o;
} catch (Exception e) {
return null;
}
}
/**
* Extracts integer value from end attr
*/
private void initColumnsCount(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
this.columns = getAttribute("columns");
if (columns != null) {
try {
itContext._columns = Integer.parseInt((String) columns.getObject(ctx));
if (itContext._columns < 0) {
itContext._columns = 0; // If end is negative set up zero
}
} catch (Exception e) {
itContext._columns = 0;
}
} else {
itContext._columns = 0;
}
}
/**
* Extracts integer value from begin attr
*/
private void initBegin(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
this.begin = getAttribute("begin");
if (begin != null) {
try {
Object o = begin.getObject(ctx);
if (o instanceof Number) {
itContext._begin = ((Number)o).intValue();
}else if (o instanceof String) {
itContext._begin = Integer.parseInt((String) o);
}
itContext._begin--;
if (itContext._begin < 0) {
itContext._begin = 0; // If end is negative set up zero
}
} catch (Exception e) {
itContext._begin = 0;
}
} else {
itContext._begin = 0;
}
}
/**
* Extracts integer value from end attr
*/
private void initEnd(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
this.end = getAttribute("end");
if (end != null) {
try {
Object o = end.getObject(ctx);
if (o instanceof Number) {
itContext._end = ((Number)o).intValue();
}else if ( o instanceof String) {
itContext._end = Integer.parseInt((String) o);
}
if (itContext._end < 0) {
itContext._end = 0; // If end is negative set up zero
}
} catch (Exception e) {
itContext._end = 0;
}
} else {
itContext._end = 0;
}
}
/**
* Extracts string value from var attr
*/
private void initVar(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
this.var = getAttribute("var");
if (var != null) {
try {
itContext._itemId = (String) var.getObject(ctx);
} catch (ClassCastException e) {
itContext._itemId = null;
}
}
}
/**
* Extracts string value from index attr
*/
private void initIndex(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
this.index = getAttribute("index");
if (index != null) {
try {
itContext._indexId = (String) index.getObject(ctx);
} catch (ClassCastException e) {
itContext._indexId = null;
}
}
}
private void initRendered(FaceletContext ctx) {
TagAttribute renderedAttribute = getAttribute("rendered");
if (renderedAttribute != null) {
try {
this.rendered = (Boolean) renderedAttribute.getObject(ctx);
} catch (ClassCastException e) {
this.rendered = true;
}
}
}
/*
* (non-Javadoc)
*
* @see org.richfaces.taglib.ComponentHandler#apply(com.sun.facelets.FaceletContext,
* javax.faces.component.UIComponent)
*/
//@Override
public void apply(FaceletContext ctx, UIComponent parent)
throws IOException, FacesException, ELException {
initRendered(ctx);
if(!rendered){
return;
}
IterationContext iterationContext = new IterationContext();
iterationContextLocal.set(iterationContext);
clearOldColumns(parent);
prepare(ctx); // prepare data
try {
while (hasNext()) { // for each
exposeVariables(ctx);
handler.apply(ctx, parent);
next(ctx);
}
} catch (Exception e) {
// TODO: handle exception
} finally {
release();
unExposeVariables(ctx);
}
}
private void clearOldColumns (UIComponent parent) {
if (parent.getChildren() != null) {
Iterator<UIComponent> childrenIt = parent.getChildren().iterator();
List<UIComponent> forDelete = new ArrayList<UIComponent>();
while (childrenIt.hasNext()) {
UIComponent c = childrenIt.next();
if (c instanceof UIColumn && c.getAttributes().get(DYNAMIC_COLUMN_MARKER) != null
&& (Boolean)c.getAttributes().get(DYNAMIC_COLUMN_MARKER)) {
forDelete.add(c);
}
}
if (forDelete.size() > 0) {
Iterator<UIComponent> it = forDelete.iterator();
while (it.hasNext()) {
parent.getChildren().remove(it.next());
}
}
}
}
/**
* Sets page request variables
*
* @throws JspTagException
*/
private void exposeVariables(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
VariableMapper vm = ctx.getVariableMapper();
int k = itContext._index;
if (itContext._itemId != null) {
if (vm != null) {
if (value != null) {
ValueExpression srcVE = value.getValueExpression(ctx,
Object.class);
ValueExpression ve = getVarExpression(ctx, srcVE);
vm.setVariable(itContext._itemId, ve);
}
}
}
// Set up index variable
if (itContext._indexId != null) {
if (vm != null) {
ValueExpression ve = new IteratedIndexExpression(k);
vm.setVariable(itContext._indexId, ve);
}
}
}
/**
* Removes page attributes that we have exposed and, if applicable, restores
* them to their prior values (and scopes).
*/
private void unExposeVariables(FaceletContext ctx) {
IterationContext itContext = getIterationContext();
VariableMapper vm = ctx.getVariableMapper();
// "nested" variables are now simply removed
if (itContext._itemId != null) {
if (vm != null)
vm.setVariable(itContext._itemId, null);
}
if (itContext._indexId != null) {
if (vm != null)
vm.setVariable(itContext._indexId, null);
}
}
/**
* Return expression for page variables
*
* @param expr
* @return
*/
private ValueExpression getVarExpression(FaceletContext ctx,
ValueExpression expr/*, IterationContext itContext*/) {
IterationContext itContext = getIterationContext();
Object o = expr.getValue(ctx.getFacesContext().getELContext());
int k = itContext._index;
if (o.getClass().isArray() || o instanceof List) {
return new IndexedValueExpression(expr, k);
}
if (o instanceof Collection || o instanceof Iterator
|| o instanceof Enumeration || o instanceof Map
|| o instanceof String) {
if (itContext.iteratedExpression == null) {
itContext.iteratedExpression = new IteratedExpression(expr, ",");
}
return new IteratedValueExpression(itContext.iteratedExpression, k);
}
throw new ELException("FOREACH_BAD_ITEMS");
}
/**
* Release iteration variables
*/
private void release() {
IterationContext itContext = getIterationContext();
itContext.items = null;
itContext._index = 0;
}
}