// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed 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.tapestry.valid;
import org.apache.tapestry.AbstractComponent;
import org.apache.tapestry.BindingException;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.TapestryUtils;
import org.apache.tapestry.form.IFormComponent;
/**
* Used to label an {@link IFormComponent}. Because such fields know their
* displayName (user-presentable name), there's no reason to hard code the label
* in a page's HTML template (this also helps with localization). [ <a
* href="../../../../../ComponentReference/FieldLabel.html">Component Reference
* </a>]
*
* @author Howard Lewis Lewis Ship
*/
public abstract class FieldLabel extends AbstractComponent
{
// Parameter
public abstract boolean isPrerender();
/**
* Gets the {@link IForm} and {@link IValidationDelegate delegate},
* then renders the label obtained from the field. Does nothing when
* rewinding.
*/
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
IForm form = TapestryUtils.getForm(cycle, this);
IFormComponent field = getField();
if (field != null && isPrerender())
form.prerenderField(writer, field, getLocation());
if (cycle.isRewinding()) return;
String displayName = getDisplayName();
if (displayName == null)
{
if (field == null)
throw Tapestry.createRequiredParameterException(this, "field");
displayName = field.getDisplayName();
if (displayName == null)
throw new BindingException(ValidMessages.noDisplayName(this,
field), this, null, getBinding("field"), null);
}
IValidationDelegate delegate = form.getDelegate();
String id = field == null ? null : field.getClientId();
delegate.writeLabelPrefix(field, writer, cycle);
writer.begin("label");
if (id != null) writer.attribute("for", id);
delegate.writeLabelAttributes(writer, cycle, field);
renderInformalParameters(writer, cycle);
writer.print(displayName, getRaw());
writer.end();
delegate.writeLabelSuffix(field, writer, cycle);
}
/** displayName parameter. */
public abstract String getDisplayName();
/** field parameter. */
public abstract IFormComponent getField();
/** raw parameter. */
public abstract boolean getRaw();
}