/**
* Licensed under the Common Development and Distribution License,
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.sun.com/cddl/
*
* 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 com.sun.facelets.tag.jstl.core;
import java.io.IOException;
import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Iterator;
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 com.sun.facelets.FaceletContext;
import com.sun.facelets.FaceletException;
import com.sun.facelets.tag.TagAttribute;
import com.sun.facelets.tag.TagAttributeException;
import com.sun.facelets.tag.TagConfig;
import com.sun.facelets.tag.TagHandler;
/**
* @author Jacob Hookom
* @author Andrew Robinson
* @version $Id: ForEachHandler.java,v 1.8 2006/03/19 03:11:34 jhook Exp $
*/
public final class ForEachHandler extends TagHandler {
private static class ArrayIterator implements Iterator {
protected final Object array;
protected int i;
protected final int len;
public ArrayIterator(Object src) {
this.i = 0;
this.array = src;
this.len = Array.getLength(src);
}
public boolean hasNext() {
return this.i < this.len;
}
public Object next() {
return Array.get(this.array, this.i++);
}
public void remove() {
throw new UnsupportedOperationException();
}
}
private final TagAttribute begin;
private final TagAttribute end;
private final TagAttribute items;
private final TagAttribute step;
private final TagAttribute tranzient;
private final TagAttribute var;
private final TagAttribute varStatus;
/**
* @param config
*/
public ForEachHandler(TagConfig config) {
super(config);
this.items = this.getAttribute("items");
this.var = this.getAttribute("var");
this.begin = this.getAttribute("begin");
this.end = this.getAttribute("end");
this.step = this.getAttribute("step");
this.varStatus = this.getAttribute("varStatus");
this.tranzient = this.getAttribute("transient");
if (this.items == null && this.begin != null && this.end == null) {
throw new TagAttributeException(
this.tag,
this.begin,
"If the 'items' attribute is not specified, but the 'begin' attribute is, then the 'end' attribute is required");
}
}
public void apply(FaceletContext ctx, UIComponent parent)
throws IOException, FacesException, FaceletException, ELException {
int s = this.getBegin(ctx);
int e = this.getEnd(ctx);
int m = this.getStep(ctx);
Integer sO = this.begin != null ? new Integer(s) : null;
Integer eO = this.end != null ? new Integer(e) : null;
Integer mO = this.step != null ? new Integer(m) : null;
boolean t = this.getTransient(ctx);
Object src = null;
ValueExpression srcVE = null;
if (this.items != null) {
srcVE = this.items.getValueExpression(ctx, Object.class);
src = srcVE.getValue(ctx);
} else {
byte[] b = new byte[e + 1];
for (int i = 0; i < b.length; i++) {
b[i] = (byte) i;
}
src = b;
}
if (src != null) {
Iterator itr = this.toIterator(src);
if (itr != null) {
int i = 0;
// move to start
while (i < s && itr.hasNext()) {
itr.next();
i++;
}
String v = this.getVarName(ctx);
String vs = this.getVarStatusName(ctx);
VariableMapper vars = ctx.getVariableMapper();
ValueExpression ve = null;
ValueExpression vO = this.capture(v, vars);
ValueExpression vsO = this.capture(vs, vars);
int mi = 0;
Object value = null;
try {
boolean first = true;
while (i <= e && itr.hasNext()) {
value = itr.next();
// set the var
if (v != null) {
if (t || srcVE == null) {
ctx.setAttribute(v, value);
} else {
ve = this.getVarExpr(srcVE, src, value, i);
vars.setVariable(v, ve);
}
}
// set the varStatus
if (vs != null) {
IterationStatus itrS = new IterationStatus(first, !itr.hasNext(),i, sO, eO, mO);
if (t || srcVE == null) {
ctx.setAttribute(vs, itrS);
} else {
ve = new IterationStatusExpression(itrS);
vars.setVariable(vs, ve);
}
}
// execute body
this.nextHandler.apply(ctx, parent);
// increment steps
mi = 1;
while (mi < m && itr.hasNext()) {
itr.next();
mi++;
i++;
}
i++;
first = false;
}
} finally {
if (v != null) {
vars.setVariable(v, vO);
}
if (vs != null) {
vars.setVariable(vs, vsO);
}
}
}
}
}
private final ValueExpression capture(String name, VariableMapper vars) {
if (name != null) {
return vars.setVariable(name, null);
}
return null;
}
private final int getBegin(FaceletContext ctx) {
if (this.begin != null) {
return this.begin.getInt(ctx);
}
return 0;
}
private final int getEnd(FaceletContext ctx) {
if (this.end != null) {
return this.end.getInt(ctx);
}
return Integer.MAX_VALUE;
}
private final int getStep(FaceletContext ctx) {
if (this.step != null) {
return this.step.getInt(ctx);
}
return 1;
}
private final boolean getTransient(FaceletContext ctx) {
if (this.tranzient != null) {
return this.tranzient.getBoolean(ctx);
}
return false;
}
private final ValueExpression getVarExpr(ValueExpression ve, Object src,
Object value, int i) {
if (src instanceof Collection || src.getClass().isArray()) {
return new IndexedValueExpression(ve, i);
} else if (src instanceof Map && value instanceof Map.Entry) {
return new MappedValueExpression(ve, (Map.Entry) value);
}
throw new IllegalStateException("Cannot create VE for: " + src);
}
private final String getVarName(FaceletContext ctx) {
if (this.var != null) {
return this.var.getValue(ctx);
}
return null;
}
private final String getVarStatusName(FaceletContext ctx) {
if (this.varStatus != null) {
return this.varStatus.getValue(ctx);
}
return null;
}
private final Iterator toIterator(Object src) {
if (src == null) {
return null;
} else if (src instanceof Collection) {
return ((Collection) src).iterator();
} else if (src instanceof Map) {
return ((Map) src).entrySet().iterator();
} else if (src.getClass().isArray()) {
return new ArrayIterator(src);
} else {
throw new TagAttributeException(this.tag, this.items,
"Must evaluate to a Collection, Map, Array, or null.");
}
}
}