org.apache.struts2.views.velocity.components.AbstractDirective Maven / Gradle / Ivy
/*
* 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.struts2.views.velocity.components;
import com.opensymphony.xwork2.inject.Container;
import com.opensymphony.xwork2.util.ValueStack;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.components.Component;
import org.apache.struts2.util.ValueStackProvider;
import org.apache.struts2.views.util.ContextUtil;
import org.apache.velocity.context.AbstractContext;
import org.apache.velocity.context.Context;
import org.apache.velocity.context.InternalContextAdapter;
import org.apache.velocity.context.InternalWrapperContext;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.directive.Directive;
import org.apache.velocity.runtime.parser.node.Node;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;
public abstract class AbstractDirective extends Directive {
public String getName() {
return "s" + getBeanName();
}
public abstract String getBeanName();
/**
* @return All components, unless otherwise stated, are LINE-level directives.
*
*/
public int getType() {
return LINE;
}
protected abstract Component getBean(ValueStack stack, HttpServletRequest req, HttpServletResponse res);
public boolean render(InternalContextAdapter ctx, Writer writer, Node node) throws IOException, ResourceNotFoundException, ParseErrorException, MethodInvocationException {
ValueStack stack = extractValueStack(ctx);
if (stack == null) {
// Fallback to assuming the ValueStack was put into the Velocity context (as is by default)
stack = (ValueStack) ctx.get(ContextUtil.STACK);
}
HttpServletRequest req = (HttpServletRequest) stack.getContext().get(ServletActionContext.HTTP_REQUEST);
HttpServletResponse res = (HttpServletResponse) stack.getContext().get(ServletActionContext.HTTP_RESPONSE);
Component bean = getBean(stack, req, res);
Container container = stack.getActionContext().getContainer();
container.inject(bean);
// get the parameters
Map params = createPropertyMap(ctx, node);
bean.copyParams(params);
//bean.addAllParameters(params);
bean.start(writer);
if (getType() == BLOCK) {
Node body = node.jjtGetChild(node.jjtGetNumChildren() - 1);
body.render(ctx, writer);
}
bean.end(writer, "");
return true;
}
private ValueStack extractValueStack(Context context) {
do {
if (context instanceof ValueStackProvider) {
return ((ValueStackProvider) context).getValueStack();
}
context = extractContext(context);
} while (context != null);
return null;
}
private Context extractContext(Context context) {
if (context instanceof InternalWrapperContext) {
return ((InternalWrapperContext) context).getInternalUserContext();
}
if (context instanceof AbstractContext) {
return ((AbstractContext) context).getChainedContext();
}
return null;
}
/**
*
* Create a Map of properties that the user has passed in. For example:
*
*
*
* #xxx("name=hello" "value=world" "template=foo")
*
*
*
* would yield a params that contains {["name", "hello"], ["value", "world"], ["template", "foo"]}
*
* @param contextAdapter the context adapter
* @param node the Node passed in to the render method
* @return a Map of the user specified properties
* @throws org.apache.velocity.exception.ParseErrorException
* if the was an error in the format of the property
*/
protected Map createPropertyMap(InternalContextAdapter contextAdapter, Node node) throws ParseErrorException, MethodInvocationException {
Map propertyMap;
int children = node.jjtGetNumChildren();
if (getType() == BLOCK) {
children--;
}
// Velocity supports an on-the-fly Map-definition syntax that leads
// to more readable and faster code:
//
// #url({'id':'url', 'action':'MyAction'})
//
// We support this syntax by checking for a single Map argument
// to any directive and using that as the property map instead
// of building one from individual name-value pair strings.
Node firstChild = null;
Object firstValue = null;
if(children == 1
&& null != (firstChild = node.jjtGetChild(0))
&& null != (firstValue = firstChild.value(contextAdapter))
&& firstValue instanceof Map) {
propertyMap = (Map)firstValue;
} else {
propertyMap = new HashMap();
for (int index = 0, length = children; index < length; index++) {
this.putProperty(propertyMap, contextAdapter, node.jjtGetChild(index));
}
}
return propertyMap;
}
/**
* adds a given Node's key/value pair to the propertyMap. For example, if this Node contained the value "rows=20",
* then the key, rows, would be added to the propertyMap with the String value, 20.
*
* @param propertyMap a params containing all the properties that we wish to set
* @param contextAdapter the context adapter
* @param node the parameter to set expressed in "name=value" format
*
* @throws ParseErrorException in case of parsing errors
* @throws MethodInvocationException in case of method invocation errors
*/
protected void putProperty(Map propertyMap, InternalContextAdapter contextAdapter, Node node) throws ParseErrorException, MethodInvocationException {
// node.value uses the StrutsValueStack to evaluate the directive's value parameter
String param = node.value(contextAdapter).toString();
int idx = param.indexOf('=');
if (idx != -1) {
String property = param.substring(0, idx);
String value = param.substring(idx + 1);
propertyMap.put(property, value);
} else {
throw new ParseErrorException("#" + this.getName() + " arguments must include an assignment operator! For example #tag( Component \"template=mytemplate\" ). #tag( TextField \"mytemplate\" ) is illegal!");
}
}
}