/*
* $Id: AbstractRenderer.java 471754 2006-11-06 14:55:09Z husted $
*
* 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 org.apache.struts.faces.renderer;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import javax.faces.application.FacesMessage;
import javax.faces.component.EditableValueHolder;
import javax.faces.component.UIComponent;
import javax.faces.component.ValueHolder;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.convert.Converter;
import javax.faces.convert.ConverterException;
import javax.faces.el.ValueBinding;
import javax.faces.render.Renderer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* <p>Abstract base class for concrete implementations of
* <code>javax.faces.render.Renderer</code> for the
* <em>Struts-Faces Integration Library</em>.</p>
*
* @version $Rev: 471754 $ $Date: 2006-11-06 15:55:09 +0100 (Lun, 06 nov 2006) $
*/
public abstract class AbstractRenderer extends Renderer {
// -------------------------------------------------------- Static Variables
private static final Log log =
LogFactory.getLog(AbstractRenderer.class);
// -------------------------------------------------------- Renderer Methods
/**
* <p>Decode any new state of the specified <code>UIComponent</code>
* from the request contained in the specified <code>FacesContext</code>,
* and store that state on the <code>UIComponent</code>.</p>
*
* <p>The default implementation calls <code>setSubmittedValue()</code>
* unless this component has a boolean <code>disabled</code> or
* <code>readonly</code> attribute that is set to <code>true</code>.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>UIComponent</code> to be decoded
*
* @exception NullPointerException if <code>context</code> or
* <code>component</code> is <code>null</code>
*/
public void decode(FacesContext context, UIComponent component) {
// Enforce NPE requirements in the Javadocs
if ((context == null) || (component == null)) {
throw new NullPointerException();
}
// Disabled or readonly components are not decoded
if (isDisabled(component) || isReadOnly(component)) {
return;
}
// Save submitted value on EditableValueHolder components
if (component instanceof EditableValueHolder) {
setSubmittedValue(context, component);
}
}
/**
* <p>Render the beginning of the specified <code>UIComponent</code>
* to the output stream or writer associated with the response we are
* creating.</p>
*
* <p>The default implementation calls <code>renderStart()</code> and
* <code>renderAttributes()</code>.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>UIComponent</code> to be decoded
*
* @exception NullPointerException if <code>context</code> or
* <code>component</code> is <code>null</code>
*
* @exception IOException if an input/output error occurs
*/
public void encodeBegin(FacesContext context, UIComponent component)
throws IOException {
// Enforce NPE requirements in the Javadocs
if ((context == null) || (component == null)) {
throw new NullPointerException();
}
if (log.isTraceEnabled()) {
log.trace("encodeBegin(id=" + component.getId() +
", family=" + component.getFamily() +
", rendererType=" + component.getRendererType() + ")");
}
// Render the element and attributes for this component
ResponseWriter writer = context.getResponseWriter();
renderStart(context, component, writer);
renderAttributes(context, component, writer);
}
/**
* <p>Render the children of the specified <code>UIComponent</code>
* to the output stream or writer associated with the response we are
* creating.</p>
*
* <p>The default implementation iterates through the children of
* this component and renders them.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>UIComponent</code> to be decoded
*
* @exception NullPointerException if <code>context</code> or
* <code>component</code> is <code>null</code>
*
* @exception IOException if an input/output error occurs
*/
public void encodeChildren(FacesContext context, UIComponent component)
throws IOException {
if (context == null || component == null) {
throw new NullPointerException();
}
if (log.isTraceEnabled()) {
log.trace("encodeChildren(id=" + component.getId() +
", family=" + component.getFamily() +
", rendererType=" + component.getRendererType() + ")");
}
Iterator kids = component.getChildren().iterator();
while (kids.hasNext()) {
UIComponent kid = (UIComponent) kids.next();
kid.encodeBegin(context);
if (kid.getRendersChildren()) {
kid.encodeChildren(context);
}
kid.encodeEnd(context);
}
if (log.isTraceEnabled()) {
log.trace("encodeChildren(id=" + component.getId() + ") end");
}
}
/**
* <p>Render the ending of the specified <code>UIComponent</code>
* to the output stream or writer associated with the response we are
* creating.</p>
*
* <p>The default implementation calls <code>renderEnd()</code>.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>UIComponent</code> to be decoded
*
* @exception NullPointerException if <code>context</code> or
* <code>component</code> is <code>null</code>
*
* @exception IOException if an input/output error occurs
*/
public void encodeEnd(FacesContext context, UIComponent component)
throws IOException {
// Enforce NPE requirements in the Javadocs
if ((context == null) || (component == null)) {
throw new NullPointerException();
}
if (log.isTraceEnabled()) {
log.trace("encodeEnd(id=" + component.getId() +
", family=" + component.getFamily() +
", rendererType=" + component.getRendererType() + ")");
}
// Render the element closing for this component
ResponseWriter writer = context.getResponseWriter();
renderEnd(context, component, writer);
}
// --------------------------------------------------------- Package Methods
// ------------------------------------------------------- Protected Methods
/**
* <p>Render nested child components by invoking the encode methods
* on those components, but only when the <code>rendered</code>
* property is <code>true</code>.</p>
*/
protected void encodeRecursive(FacesContext context, UIComponent component)
throws IOException {
// suppress rendering if "rendered" property on the component is
// false.
if (!component.isRendered()) {
return;
}
// Render this component and its children recursively
if (log.isTraceEnabled()) {
log.trace("encodeRecursive(id=" + component.getId() +
", family=" + component.getFamily() +
", rendererType=" + component.getRendererType() +
") encodeBegin");
}
component.encodeBegin(context);
if (component.getRendersChildren()) {
if (log.isTraceEnabled()) {
log.trace("encodeRecursive(id=" + component.getId() +
") delegating");
}
component.encodeChildren(context);
} else {
if (log.isTraceEnabled()) {
log.trace("encodeRecursive(id=" + component.getId() +
") recursing");
}
Iterator kids = component.getChildren().iterator();
while (kids.hasNext()) {
UIComponent kid = (UIComponent) kids.next();
encodeRecursive(context, kid);
}
}
if (log.isTraceEnabled()) {
log.trace("encodeRecursive(id=" + component.getId() + ") encodeEnd");
}
component.encodeEnd(context);
}
/**
* <p>Return <code>true</code> if the specified component is disabled.</p>
*
* @param component <code>UIComponent</code> to be checked
*/
protected boolean isDisabled(UIComponent component) {
Object disabled = component.getAttributes().get("disabled");
if (disabled == null) {
return (false);
}
if (disabled instanceof String) {
return (Boolean.valueOf((String) disabled).booleanValue());
} else {
return (disabled.equals(Boolean.TRUE));
}
}
/**
* <p>Return <code>true</code> if the specified component is read only.</p>
*
* @param component <code>UIComponent</code> to be checked
*/
protected boolean isReadOnly(UIComponent component) {
Object readonly = component.getAttributes().get("readonly");
if (readonly == null) {
return (false);
}
if (readonly instanceof String) {
return (Boolean.valueOf((String) readonly).booleanValue());
} else {
return (readonly.equals(Boolean.TRUE));
}
}
/**
* <p>Render the element attributes for the generated markup related to this
* component. Simple renderers that create a single markup element
* for this component should override this method and include calls to
* to <code>writeAttribute()</code> and <code>writeURIAttribute</code>
* on the specified <code>ResponseWriter</code>.</p>
*
* <p>The default implementation does nothing.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>EditableValueHolder</code> component whose
* submitted value is to be stored
* @param writer <code>ResponseWriter</code> to which the element
* start should be rendered
*
* @exception IOException if an input/output error occurs
*/
protected void renderAttributes(FacesContext context, UIComponent component,
ResponseWriter writer) throws IOException {
}
/**
* <p>Render the element end for the generated markup related to this
* component. Simple renderers that create a single markup element
* for this component should override this method and include a call
* to <code>endElement()</code> on the specified
* <code>ResponseWriter</code>.</p>
*
* <p>The default implementation does nothing.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>EditableValueHolder</code> component whose
* submitted value is to be stored
* @param writer <code>ResponseWriter</code> to which the element
* start should be rendered
*
* @exception IOException if an input/output error occurs
*/
protected void renderEnd(FacesContext context, UIComponent component,
ResponseWriter writer) throws IOException {
}
/**
* <p>Render any boolean attributes on the specified list that have
* <code>true</code> values on the corresponding attribute of the
* specified <code>UIComponent</code>.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>EditableValueHolder</code> component whose
* submitted value is to be stored
* @param writer <code>ResponseWriter</code> to which the element
* start should be rendered
* @param names List of attribute names to be passed through
*
* @exception IOException if an input/output error occurs
*/
protected void renderBoolean(FacesContext context,
UIComponent component,
ResponseWriter writer,
String names[]) throws IOException {
if (names == null) {
return;
}
Map attributes = component.getAttributes();
boolean flag;
Object value;
for (int i = 0; i < names.length; i++) {
value = attributes.get(names[i]);
if (value != null) {
if (value instanceof String) {
flag = Boolean.valueOf((String) value).booleanValue();
} else {
flag = Boolean.valueOf(value.toString()).booleanValue();
}
if (flag) {
writer.writeAttribute(names[i], names[i], names[i]);
flag = false;
}
}
}
}
/**
* <p>Render any attributes on the specified list directly to the
* specified <code>ResponseWriter</code> for which the specified
* <code>UIComponent</code> has a non-<code>null</code> attribute value.
* This method may be used to "pass through" commonly used attribute
* name/value pairs with a minimum of code.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>EditableValueHolder</code> component whose
* submitted value is to be stored
* @param writer <code>ResponseWriter</code> to which the element
* start should be rendered
* @param names List of attribute names to be passed through
*
* @exception IOException if an input/output error occurs
*/
protected void renderPassThrough(FacesContext context,
UIComponent component,
ResponseWriter writer,
String names[]) throws IOException {
if (names == null) {
return;
}
Map attributes = component.getAttributes();
Object value;
for (int i = 0; i < names.length; i++) {
value = attributes.get(names[i]);
if (value != null) {
if (value instanceof String) {
writer.writeAttribute(names[i], value, names[i]);
} else {
writer.writeAttribute(names[i], value.toString(), names[i]);
}
}
}
}
/**
* <p>Render the element start for the generated markup related to this
* component. Simple renderers that create a single markup element
* for this component should override this method and include a call
* to <code>startElement()</code> on the specified
* <code>ResponseWriter</code>.</p>
*
* <p>The default implementation does nothing.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>EditableValueHolder</code> component whose
* submitted value is to be stored
* @param writer <code>ResponseWriter</code> to which the element
* start should be rendered
*
* @exception IOException if an input/output error occurs
*/
protected void renderStart(FacesContext context, UIComponent component,
ResponseWriter writer) throws IOException {
}
/**
* <p>If a submitted value was included on this request, store it in the
* component as appropriate.</p>
*
* <p>The default implementation determines whether this component
* implements <code>EditableValueHolder</code>. If so, it checks for a
* request parameter with the same name as the <code>clientId</code>
* of this <code>UIComponent</code>. If there is such a parameter, its
* value is passed (as a String) to the <code>setSubmittedValue()</code>
* method on the <code>EditableValueHolder</code> component.</p>
*
* @param context <code>FacesContext</code> for the current request
* @param component <code>EditableValueHolder</code> component whose
* submitted value is to be stored
*/
protected void setSubmittedValue
(FacesContext context, UIComponent component) {
if (!(component instanceof EditableValueHolder)) {
return;
}
String clientId = component.getClientId(context);
Map parameters = context.getExternalContext().getRequestParameterMap();
if (parameters.containsKey(clientId)) {
if (log.isTraceEnabled()) {
log.trace("setSubmittedValue(" + clientId + "," +
(String) parameters.get(clientId));
}
component.getAttributes().put("submittedValue",
parameters.get(clientId));
}
}
// --------------------------------------------------------- Private Methods
/**
* <p>Decode the current state of the specified UIComponent from the
* request contained in the specified <code>FacesContext</code>, and
* attempt to convert this state information into an object of the
* type equired for this component.</p>
*
* @param context FacesContext for the request we are processing
* @param component UIComponent to be decoded
*
* @exception NullPointerException if context or component is null
*/
/*
public void decode(FacesContext context, UIComponent component) {
// Enforce NPE requirements in the Javadocs
if ((context == null) || (component == null)) {
throw new NullPointerException();
}
// Only input components need to be decoded
if (!(component instanceof UIInput)) {
return;
}
UIInput input = (UIInput) component;
// Save the old value for use in generating ValueChangedEvents
Object oldValue = input.getValue();
if (oldValue instanceof String) {
try {
oldValue = getAsObject(context, component, (String) oldValue);
} catch (ConverterException e) {
;
}
}
input.setPrevious(oldValue);
// Decode and convert (if needed) the new value
String clientId = component.getClientId(context);
Map map = context.getExternalContext().getRequestParameterMap();
String newString = (String) map.get(clientId);
Object newValue = null;
try {
newValue = getAsObject(context, component, newString);
input.setValue(newValue);
input.setValid(true);
} catch (ConverterException e) {
input.setValue(newValue);
input.setValid(false);
addConverterMessage(context, component, e.getMessage());
}
}
*/
// --------------------------------------------------------- Package Methods
// ------------------------------------------------------- Protected Methods
/**
* <p>Add an error message denoting a conversion failure.</p>
*
* @param context The <code>FacesContext</code> for this request
* @param component The <code>UIComponent</code> that experienced
* the conversion failure
* @param text The text of the error message
*/
/*
protected void addConverterMessage(FacesContext context,
UIComponent component,
String text) {
String clientId = component.getClientId(context);
FacesMessage message = new FacesMessage
(text,
"Conversion error on component '" + clientId + "'");
context.addMessage(clientId, message);
}
*/
/**
* <p>Convert the String representation of this component's value
* to the corresponding Object representation. The default
* implementation utilizes the <code>getAsObject()</code> method of any
* associated <code>Converter</code>.</p>
*
* @param context The <code>FacesContext</code> for this request
* @param component The <code>UIComponent</code> whose value is
* being converted
* @param value The String representation to be converted
*
* @exception ConverterException if conversion fails
*/
/*
protected Object getAsObject(FacesContext context, UIComponent component,
String value) throws ConverterException {
// Identify any Converter associated with this component value
ValueBinding vb = component.getValueBinding("value");
Converter converter = null;
if (component instanceof ValueHolder) {
// Acquire explicitly assigned Converter (if any)
converter = ((ValueHolder) component).getConverter();
}
if ((converter == null) && (vb != null)) {
Class type = vb.getType(context);
if ((type == null) || (type == String.class)) {
return (value); // No conversion required for Strings
}
// Acquire implicit by-type Converter (if any)
converter = context.getApplication().createConverter(type);
}
// Convert the result if we identified a Converter
if (converter != null) {
return (converter.getAsObject(context, component, value));
} else {
return (value);
}
}
*/
/**
* <p>Convert the Object representation of this component's value
* to the corresponding String representation. The default implementation
* utilizes the <code>getAsString()</code> method of any associated
* <code>Converter</code>.</p>
*
* @param context The <code>FacesContext</code> for this request
* @param component The <code>UIComponent</code> whose value is
* being converted
* @param value The Object representation to be converted
*
* @exception ConverterException if conversion fails
*/
protected String getAsString(FacesContext context, UIComponent component,
Object value) throws ConverterException {
// Identify any Converter associated with this component value
ValueBinding vb = component.getValueBinding("value");
Converter converter = null;
if (component instanceof ValueHolder) {
// Acquire explicitly assigned Converter (if any)
converter = ((ValueHolder) component).getConverter();
}
if ((converter == null) && (vb != null)) {
// Acquire implicit by-type Converter (if any)
Class type = vb.getType(context);
if (type != null) {
converter = context.getApplication().createConverter(type);
}
}
// Convert the result if we identified a Converter
if (converter != null) {
return (converter.getAsString(context, component, value));
} else if (value == null) {
return ("");
} else if (value instanceof String) {
return ((String) value);
} else {
return (value.toString());
}
}
}