// 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.hivemind.ApplicationRuntimeException;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.PageRenderSupport;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.TapestryUtils;
/**
* Implements a component that submits its enclosing form via a JavaScript link. [ <a
* href="../../../../../ComponentReference/LinkSubmit.html">Component Reference </a>]
*
* @author Richard Lewis-Shell
*/
public abstract class LinkSubmit extends AbstractSubmit
{
/**
* The name of an {@link org.apache.tapestry.IRequestCycle}attribute in which the current
* submit link is stored. LinkSubmits do not nest.
*/
public static final String ATTRIBUTE_NAME = "org.apache.tapestry.form.LinkSubmit";
/**
* The name of an {@link org.apache.tapestry.IRequestCycle}attribute in which the link submit
* component that generates the javascript function is stored. The function is only required
* once per page (containing a form with a non-disabled LinkSubmit)
*/
public static final String ATTRIBUTE_FUNCTION_NAME = "org.apache.tapestry.form.LinkSubmit_function";
protected boolean isClicked(IRequestCycle cycle, String name)
{
// How to know which Submit link was actually
// clicked? When submitted, it sets its elementId into a hidden field
String value = cycle.getParameter("_linkSubmit");
// If the value isn't the elementId of this component, then this link wasn't
// selected.
return value != null && value.equals(name);
}
protected void writeTag(IMarkupWriter writer, IRequestCycle cycle, String name)
{
boolean disabled = isDisabled();
IMarkupWriter wrappedWriter;
if (!disabled)
{
PageRenderSupport pageRenderSupport = TapestryUtils.getPageRenderSupport(
cycle,
this);
// make sure the submit function is on the page (once)
if (cycle.getAttribute(ATTRIBUTE_FUNCTION_NAME) == null)
{
pageRenderSupport
.addBodyScript("function submitLink(form, elementId) { form._linkSubmit.value = elementId; if (form.onsubmit == null || form.onsubmit()) form.submit(); }");
cycle.setAttribute(ATTRIBUTE_FUNCTION_NAME, this);
}
IForm form = getForm(cycle);
String formName = form.getName();
// one hidden field per form:
String formHiddenFieldAttributeName = ATTRIBUTE_FUNCTION_NAME + formName;
if (cycle.getAttribute(formHiddenFieldAttributeName) == null)
{
writer.beginEmpty("input");
writer.attribute("type", "hidden");
writer.attribute("name", "_linkSubmit");
cycle.setAttribute(formHiddenFieldAttributeName, this);
}
writer.begin("a");
writer.attribute("href", "javascript:submitLink(document." + formName + ",\"" + name
+ "\");");
// Allow the wrapped components a chance to render.
// Along the way, they may interact with this component
// and cause the name variable to get set.
wrappedWriter = writer.getNestedWriter();
}
else
wrappedWriter = writer;
renderBody(wrappedWriter, cycle);
if (!disabled)
{
// Generate additional attributes from informal parameters.
renderInformalParameters(writer, cycle);
// Dump in HTML provided by wrapped components
wrappedWriter.close();
// Close the <a> tag
writer.end();
}
}
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
if (cycle.getAttribute(ATTRIBUTE_NAME) != null)
throw new ApplicationRuntimeException(Tapestry.getMessage("LinkSubmit.may-not-nest"),
this, null, null);
cycle.setAttribute(ATTRIBUTE_NAME, this);
try
{
super.renderComponent(writer, cycle);
}
finally
{
cycle.removeAttribute(ATTRIBUTE_NAME);
}
}
}