jakarta.faces.component.SelectUtils Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jakarta.faces Show documentation
Show all versions of jakarta.faces Show documentation
EE4J Compatible Implementation for Jakarta Faces API
/*
* Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.faces.component;
import java.util.Iterator;
import java.util.NoSuchElementException;
import jakarta.el.ELException;
import jakarta.el.ExpressionFactory;
import jakarta.faces.context.FacesContext;
import jakarta.faces.convert.Converter;
import jakarta.faces.model.SelectItem;
import jakarta.faces.model.SelectItemGroup;
/**
* Contains common utility methods used by both {@link UISelectOne} and {@link UISelectMany}.
*/
class SelectUtils {
// ------------------------------------------------------------ Constructors
private SelectUtils() {
}
// ------------------------------------------------- Package Private Methods
/**
*
* Return true if the specified value matches one of the available options, performing a recursive search
* if if a {@link jakarta.faces.model.SelectItemGroup} instance is detected.
*
*
* @param ctx {@link FacesContext} for the current request
* @param value {@link UIComponent} value to be tested
* @param items Iterator over the {@link jakarta.faces.model.SelectItem}s to be checked
* @param converter the {@link Converter} associated with this component
*/
static boolean matchValue(FacesContext ctx, UIComponent component, Object value, Iterator items, Converter converter) {
while (items.hasNext()) {
SelectItem item = items.next();
if (item instanceof SelectItemGroup) {
SelectItem subitems[] = ((SelectItemGroup) item).getSelectItems();
if (subitems != null && subitems.length > 0) {
if (matchValue(ctx, component, value, new ArrayIterator(subitems), converter)) {
return true;
}
}
} else {
Object compareValue = null;
try {
compareValue = doConversion(ctx, component, item, value, converter);
} catch (IllegalStateException ise) {
continue;
}
if (null == compareValue && null == value) {
return true;
}
if (value.equals(compareValue)) {
return true;
}
}
}
return false;
}
/**
* Returns true iff component has a {@link UISelectItem} child whose itemValue exactly matches the argument value
*
* @param ctx
* @param component
* @param value
* @param items
* @return
*/
static boolean valueIsNoSelectionOption(FacesContext ctx, UIComponent component, Object value, Iterator items, Converter converter) {
boolean result = false;
while (items.hasNext()) {
SelectItem item = items.next();
if (item instanceof SelectItemGroup) {
SelectItem subitems[] = ((SelectItemGroup) item).getSelectItems();
if (subitems != null && subitems.length > 0) {
if (valueIsNoSelectionOption(ctx, component, value, new ArrayIterator(subitems), converter)) {
result = true;
break;
}
}
} else {
Object compareValue = null;
try {
compareValue = doConversion(ctx, component, item, value, converter);
} catch (IllegalStateException ise) {
continue;
}
if (null == compareValue && null == value && item.isNoSelectionOption()) {
result = true;
break;
} else if (value.equals(compareValue) && item.isNoSelectionOption()) {
result = true;
break;
}
}
}
return result;
}
private static Object doConversion(FacesContext ctx, UIComponent component, SelectItem item, Object value, Converter converter)
throws IllegalStateException {
Object itemValue = item.getValue();
if (itemValue == null && value == null) {
return null;
}
if (value == null ^ itemValue == null) {
throw new IllegalStateException("Either value was null, or itemValue was null, but not both.");
}
Object compareValue;
if (converter == null) {
compareValue = coerceToModelType(ctx, itemValue, value.getClass());
} else {
compareValue = itemValue;
if (compareValue instanceof String && !(value instanceof String)) {
// type mismatch between the time and the value we're
// comparing. Invoke the Converter.
compareValue = converter.getAsObject(ctx, component, (String) compareValue);
}
}
return compareValue;
}
/**
* Coerce the provided value to the specified type using Jakarta Expression Language coercion.
*
* @param ctx the {@link FacesContext} for the current request
* @param value the value to coerce
* @param toType the type value should be coerced to
*
* @return the result of the Jakarta Expression Language coersion
*
* @see ExpressionFactory#coerceToType(Object, Class)
*/
private static Object coerceToModelType(FacesContext ctx, Object value, Class toType) {
Object newValue;
try {
ExpressionFactory ef = ctx.getApplication().getExpressionFactory();
newValue = ef.coerceToType(value, toType);
} catch (ELException | IllegalArgumentException ele) {
// If coerceToType fails, per the docs it should throw
// an ELException, however, GF 9.0 and 9.0u1 will throw
// an IllegalArgumentException instead (see GF issue 1527).
newValue = value;
}
return newValue;
}
// ---------------------------------------------------------- Nested Classes
/**
* Exposes an Array via an Iterator
*/
static class ArrayIterator implements Iterator {
public ArrayIterator(Object items[]) {
this.items = items;
}
private Object items[];
private int index = 0;
@Override
public boolean hasNext() {
return index < items.length;
}
@Override
public Object next() {
try {
return items[index++];
} catch (IndexOutOfBoundsException e) {
throw new NoSuchElementException();
}
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
} // END ArrayIterator
}