// 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.tapestry5.internal.transform;
import org.apache.tapestry5.EventConstants;
import org.apache.tapestry5.Link;
import org.apache.tapestry5.ValueEncoder;
import org.apache.tapestry5.annotations.ActivationRequestParameter;
import org.apache.tapestry5.internal.services.ComponentClassCache;
import org.apache.tapestry5.ioc.internal.util.TapestryException;
import org.apache.tapestry5.ioc.util.IdAllocator;
import org.apache.tapestry5.model.MutableComponentModel;
import org.apache.tapestry5.plastic.FieldHandle;
import org.apache.tapestry5.plastic.PlasticClass;
import org.apache.tapestry5.plastic.PlasticField;
import org.apache.tapestry5.runtime.Component;
import org.apache.tapestry5.runtime.ComponentEvent;
import org.apache.tapestry5.services.ComponentEventHandler;
import org.apache.tapestry5.services.Request;
import org.apache.tapestry5.services.URLEncoder;
import org.apache.tapestry5.services.ValueEncoderSource;
import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
import org.apache.tapestry5.services.transform.TransformationSupport;
/**
* Hooks the activate event handler on the component (presumably, a page) to
* extract query parameters, and hooks the link decoration events to extract values
* and add them to the {@link Link}.
*
* @see ActivationRequestParameter
* @since 5.2.0
*/
@SuppressWarnings("all")
public class ActivationRequestParameterWorker implements ComponentClassTransformWorker2
{
private final Request request;
private final ComponentClassCache classCache;
private final ValueEncoderSource valueEncoderSource;
private final URLEncoder urlEncoder;
public ActivationRequestParameterWorker(Request request, ComponentClassCache classCache,
ValueEncoderSource valueEncoderSource, URLEncoder urlEncoder)
{
this.request = request;
this.classCache = classCache;
this.valueEncoderSource = valueEncoderSource;
this.urlEncoder = urlEncoder;
}
public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
{
for (PlasticField field : plasticClass.getFieldsWithAnnotation(ActivationRequestParameter.class))
{
mapFieldToQueryParameter(field, support);
}
}
private void mapFieldToQueryParameter(PlasticField field, TransformationSupport support)
{
ActivationRequestParameter annotation = field.getAnnotation(ActivationRequestParameter.class);
String parameterName = getParameterName(field, annotation);
// Assumption: the field type is not one that's loaded by the component class loader, so it's safe
// to convert to a hard type during class transformation.
Class fieldType = classCache.forName(field.getTypeName());
ValueEncoder encoder = valueEncoderSource.getValueEncoder(fieldType);
FieldHandle handle = field.getHandle();
String fieldName = String.format("%s.%s", field.getPlasticClass().getClassName(), field.getName());
setValueFromInitializeEventHandler(support, fieldName, annotation.required(), handle, parameterName, encoder, urlEncoder);
decorateLinks(support, fieldName, handle, parameterName, encoder, urlEncoder);
preallocateName(support, parameterName);
}
private static void preallocateName(TransformationSupport support, final String parameterName)
{
ComponentEventHandler handler = new ComponentEventHandler()
{
public void handleEvent(Component instance, ComponentEvent event)
{
IdAllocator idAllocator = event.getEventContext().get(IdAllocator.class, 0);
idAllocator.allocateId(parameterName);
}
};
support.addEventHandler(EventConstants.PREALLOCATE_FORM_CONTROL_NAMES, 1,
"ActivationRequestParameterWorker preallocate form control name '" + parameterName + "' event handler",
handler);
}
@SuppressWarnings("all")
private void setValueFromInitializeEventHandler(final TransformationSupport support, final String fieldName, final boolean required, final FieldHandle handle,
final String parameterName, final ValueEncoder encoder, final URLEncoder urlEncoder)
{
ComponentEventHandler handler = new ComponentEventHandler()
{
public void handleEvent(Component instance, ComponentEvent event)
{
String clientValue = request.getParameter(parameterName);
if (clientValue == null)
{
if (required)
{
throw new TapestryException(String.format("Activation request parameter field %s is marked as required, but query parameter '%s' is null.",
fieldName,
parameterName), null);
}
return;
}
// TAP5-1768: unescape encoded value
clientValue = urlEncoder.decode(clientValue);
Object value = encoder.toValue(clientValue);
handle.set(instance, value);
}
};
support.addEventHandler(EventConstants.ACTIVATE, 0,
String.format("Restoring field %s from query parameter '%s'", fieldName, parameterName), handler);
}
@SuppressWarnings("all")
private static void decorateLinks(TransformationSupport support, String fieldName, final FieldHandle handle,
final String parameterName, final ValueEncoder encoder, final URLEncoder urlEncoder)
{
ComponentEventHandler handler = new ComponentEventHandler()
{
public void handleEvent(Component instance, ComponentEvent event)
{
Object value = handle.get(instance);
if (value == null)
{
return;
}
Link link = event.getEventContext().get(Link.class, 0);
String clientValue = encoder.toClient(value);
// TAP5-1768: escape special characters
clientValue = urlEncoder.encode(clientValue);
link.addParameter(parameterName, clientValue);
}
};
support.addEventHandler(EventConstants.DECORATE_COMPONENT_EVENT_LINK, 0,
String.format("ActivationRequestParameterWorker decorate component event link event handler for field %s as query parameter '%s'", fieldName, parameterName), handler);
support.addEventHandler(EventConstants.DECORATE_PAGE_RENDER_LINK, 0, String.format(
"ActivationRequestParameterWorker decorate page render link event handler for field %s as query parameter '%s'", fieldName, parameterName), handler);
}
private String getParameterName(PlasticField field, ActivationRequestParameter annotation)
{
if (annotation.value().equals(""))
return field.getName();
return annotation.value();
}
}