/*
* 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.tomcat.util.digester;
import org.xml.sax.Attributes;
/**
* <p>
* Rule implementation that saves a parameter for use by a surrounding <code>CallMethodRule</code>.
* </p>
* <p>
* This parameter may be:
* </p>
* <ul>
* <li>from an attribute of the current element See {@link #CallParamRule(int paramIndex, String attributeName)}
* <li>from current the element body See {@link #CallParamRule(int paramIndex)}
* </ul>
*/
public class CallParamRule extends Rule {
// ----------------------------------------------------------- Constructors
/**
* Construct a "call parameter" rule that will save the body text of this element as the parameter value.
*
* @param paramIndex The zero-relative parameter number
*/
public CallParamRule(int paramIndex) {
this(paramIndex, null);
}
/**
* Construct a "call parameter" rule that will save the value of the specified attribute as the parameter value.
*
* @param paramIndex The zero-relative parameter number
* @param attributeName The name of the attribute to save
*/
public CallParamRule(int paramIndex, String attributeName) {
this(attributeName, paramIndex, 0, false);
}
private CallParamRule(String attributeName, int paramIndex, int stackIndex, boolean fromStack) {
this.attributeName = attributeName;
this.paramIndex = paramIndex;
this.stackIndex = stackIndex;
this.fromStack = fromStack;
}
// ----------------------------------------------------- Instance Variables
/**
* The attribute from which to save the parameter value
*/
protected final String attributeName;
/**
* The zero-relative index of the parameter we are saving.
*/
protected final int paramIndex;
/**
* Is the parameter to be set from the stack?
*/
protected final boolean fromStack;
/**
* The position of the object from the top of the stack
*/
protected final int stackIndex;
/**
* Stack is used to allow nested body text to be processed. Lazy creation.
*/
protected ArrayStack<String> bodyTextStack;
// --------------------------------------------------------- Public Methods
/**
* Process the start of this element.
*
* @param namespace the namespace URI of the matching element, or an empty string if the parser is not namespace
* aware or the element has no namespace
* @param name the local name if the parser is namespace aware, or just the element name otherwise
* @param attributes The attribute list for this element
*/
@Override
public void begin(String namespace, String name, Attributes attributes) throws Exception {
Object param = null;
if (attributeName != null) {
param = attributes.getValue(attributeName);
} else if (fromStack) {
param = digester.peek(stackIndex);
if (digester.log.isTraceEnabled()) {
String sb = "[CallParamRule]{" + digester.match + "} Save from stack; from stack? " + true +
"; object=" + param;
digester.log.trace(sb);
}
}
// Have to save the param object to the param stack frame here.
// Can't wait until end(). Otherwise, the object will be lost.
// We can't save the object as instance variables, as
// the instance variables will be overwritten
// if this CallParamRule is reused in subsequent nesting.
if (param != null) {
Object[] parameters = (Object[]) digester.peekParams();
parameters[paramIndex] = param;
}
}
/**
* Process the body text of this element.
*
* @param namespace the namespace URI of the matching element, or an empty string if the parser is not namespace
* aware or the element has no namespace
* @param name the local name if the parser is namespace aware, or just the element name otherwise
* @param bodyText The body text of this element
*/
@Override
public void body(String namespace, String name, String bodyText) throws Exception {
if (attributeName == null && !fromStack) {
// We must wait to set the parameter until end
// so that we can make sure that the right set of parameters
// is at the top of the stack
if (bodyTextStack == null) {
bodyTextStack = new ArrayStack<>();
}
bodyTextStack.push(bodyText.trim());
}
}
/**
* Process any body texts now.
*/
@Override
public void end(String namespace, String name) {
if (bodyTextStack != null && !bodyTextStack.empty()) {
// what we do now is push one parameter onto the top set of parameters
Object[] parameters = (Object[]) digester.peekParams();
parameters[paramIndex] = bodyTextStack.pop();
}
}
/**
* Render a printable version of this Rule.
*/
@Override
public String toString() {
return "CallParamRule[" + "paramIndex=" + paramIndex + ", attributeName=" + attributeName + ", from stack=" +
fromStack + ']';
}
}