// 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.form;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
/**
* Base class for implementing various types of text input fields. This includes {@link TextField}
* and {@link org.apache.tapestry.valid.ValidField}.
*
* @author Howard Lewis Ship
* @since 1.0.2
*/
public abstract class AbstractTextField extends AbstractFormComponent
{
/**
* Renders the form element, or responds when the form containing the element is submitted (by
* checking {@link Form#isRewinding()}.
*/
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
IForm form = getForm(cycle);
if (form.wasPrerendered(writer, this))
return;
// It isn't enough to know whether the cycle in general is rewinding, need to know
// specifically if the form which contains this component is rewinding.
boolean rewinding = form.isRewinding();
// If the cycle is rewinding, but the form containing this field is not,
// then there's no point in doing more work.
if (!rewinding && cycle.isRewinding())
return;
// Used whether rewinding or not.
String name = form.getElementId(this);
if (rewinding)
{
if (!isDisabled())
{
String value = cycle.getParameter(name);
updateValue(value);
}
return;
}
writer.beginEmpty("input");
writer.attribute("type", isHidden() ? "password" : "text");
if (isDisabled())
writer.attribute("disabled", "disabled");
writer.attribute("name", name);
String value = readValue();
if (value != null)
writer.attribute("value", value);
renderInformalParameters(writer, cycle);
beforeCloseTag(writer, cycle);
writer.closeTag();
}
/**
* Invoked from {@link #render(IMarkupWriter, IRequestCycle)}just before the tag is closed.
* This implementation does nothing, subclasses may override.
*/
protected void beforeCloseTag(IMarkupWriter writer, IRequestCycle cycle)
{
// Do nothing.
}
/**
* Invoked by {@link #render(IMarkupWriter writer, IRequestCycle cycle)}when a value is
* obtained from the {@link javax.servlet.http.HttpServletRequest}.
*/
abstract protected void updateValue(String value);
/**
* Invoked by {@link #render(IMarkupWriter writer, IRequestCycle cycle)}when rendering a
* response.
*
* @return the current value for the field, as a String, or null.
*/
abstract protected String readValue();
public abstract boolean isHidden();
public abstract boolean isDisabled();
}