ImportAttributeModel.java
/*
* 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.tiles.template;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.tiles.api.Attribute;
import org.apache.tiles.api.AttributeContext;
import org.apache.tiles.api.TilesContainer;
import org.apache.tiles.api.access.TilesAccess;
import org.apache.tiles.request.Request;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
/**
* <p>
* <strong>Import attribute(s) in specified context.</strong>
* </p>
* <p>
* Import attribute(s) to requested scope. Attribute name and scope are
* optional. If not specified, all attributes are imported in page scope. Once
* imported, an attribute can be used as any other beans from jsp contexts.
* </p>
*
* @since 2.2.0
*/
public class ImportAttributeModel {
/**
* The logging object.
*/
private static final Logger LOG = LogManager.getLogger(ImportAttributeModel.class);
/**
* Executes the model.
*
* @param name The name of the attribute to import. If it is
* <code>null</code>, all the attributes will be imported.
* @param scope The scope into which the attribute(s) will be imported. If
* <code>null</code>, the import will go in page scope.
* @param toName The name of the attribute into which the attribute will be
* imported. To be used in conjunction to <code>name</code>. If
* <code>null</code>, the value of <code>name</code> will be used.
* @param ignore If <code>true</code>, if the attribute is not present, the
* problem will be ignored.
* @param request The request.
*/
public void execute(
String name,
String scope,
String toName,
boolean ignore,
Request request
) {
Map<String, Object> attributes = getImportedAttributes(name, toName, ignore, request);
if (scope == null) {
scope = request.getAvailableScopes().get(0);
}
request.getContext(scope).putAll(attributes);
}
/**
* Retuns a Map that contains the attributes to be imported. The importing
* code must be done by the caller.
*
* @param name The attribute to import. If null, all the attributes will be
* imported.
* @param toName The destination name of the attribute to import. Valid only
* if <code>name</code> is specified.
* @param ignore If <code>true</code> and the attribute is not found, or an
* exception happens, the problem will be ignored.
* @param request The request.
* @return A Map of the attributes to be imported: the key is the name of an
* attribute, the value is the value of that attribute.
* @since 2.2.0
*/
private Map<String, Object> getImportedAttributes(String name, String toName, boolean ignore, Request request) {
TilesContainer container = TilesAccess.getCurrentContainer(request);
Map<String, Object> retValue = new HashMap<>();
AttributeContext attributeContext = container.getAttributeContext(request);
// Some tags allow for unspecified attributes. This
// implies that the tag should use all the attributes.
if (name != null) {
importSingleAttribute(container, attributeContext, name, toName, ignore, retValue, request);
} else {
importAttributes(attributeContext.getCascadedAttributeNames(), container, attributeContext, retValue, ignore, request);
importAttributes(attributeContext.getLocalAttributeNames(), container, attributeContext, retValue, ignore, request);
}
return retValue;
}
/**
* Imports a single attribute.
*
* @param container The Tiles container to use.
* @param attributeContext The context from which the attributes will be
* got.
* @param name The name of the attribute.
* @param toName The name of the destination attribute. If null,
* <code>name</code> will be used.
* @param ignore If <code>true</code> and the attribute is not found, or an
* exception happens, the problem will be ignored.
* @param attributes The map of the attributes to fill.
* @param request The request.
*/
private void importSingleAttribute(
TilesContainer container,
AttributeContext attributeContext,
String name, String toName,
boolean ignore,
Map<String, Object> attributes,
Request request
) {
Attribute attr = attributeContext.getAttribute(name);
if (attr != null) {
try {
Object attributeValue = container.evaluate(attr,
request);
if (attributeValue == null) {
if (!ignore) {
throw new NoSuchAttributeException("Error importing attributes. " + "Attribute '" + name + "' has a null value ");
}
} else {
if (toName != null) {
attributes.put(toName, attributeValue);
} else {
attributes.put(name, attributeValue);
}
}
} catch (RuntimeException e) {
if (!ignore) {
throw e;
} else if (LOG.isDebugEnabled()) {
LOG.debug("Ignoring Tiles Exception", e);
}
}
} else if (!ignore) {
throw new NoSuchAttributeException("Error importing attributes. " + "Attribute '" + name + "' is null");
}
}
/**
* Imports all the attributes.
*
* @param names The names of the attributes to be imported.
* @param container The Tiles container to use.
* @param attributeContext The context from which the attributes will be
* got.
* @param attributes The map of the attributes to fill.
* @param ignore If <code>true</code> and the attribute is not found, or an
* exception happens, the problem will be ignored.
* @param request The request.
*/
private void importAttributes(
Collection<String> names,
TilesContainer container,
AttributeContext attributeContext,
Map<String, Object> attributes,
boolean ignore,
Request request
) {
if (names == null || names.isEmpty()) {
return;
}
for (String name : names) {
if (name == null && !ignore) {
throw new NoSuchAttributeException("Error importing attributes. Attribute with null key found.");
} else if (name == null) {
continue;
}
importSingleAttribute(container, attributeContext, name, name, ignore, attributes, request);
}
}
}