/*
* 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.cocoon.acting;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.Iterator;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Redirector;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.SourceResolver;
/**
* This action simply checks to see if a given request parameter
* exists. It takes an arbitrary number of default parameters to check
* named 'parameter-name'. Non-default parameters need to be separated
* by spaces and passed as value of a sitemap parameter named
* 'parameters'. The action returns a map with all parameters if all
* of them exist and null otherwise. Parameter names can only be added
* to this list but no default parameters can be overridden by
* specific ones.
*
* <p>This action is very closely related to @link{RequestParamAction}
* and {@link FormValidatorAction}. However this action is considerably
* simpler in that it tests only for existence of a parameter and it
* doesn't need a descriptor. Besides it doesn't propagate all request
* parameters to the sitemap but only those that are marked as
* required.</p> <p> One special feature is, however, that parameters
* can contain <strong>one</strong> wildcard ("*"). It will be
* checked, whether all parameters with a wildcard have the same
* matches. E.g. "id_* name_*" enforces, that if "id_1" exists,
* "name_1" must also exist and vice versa.</p>
*
* @author <a href="mailto:haul@apache.org">Christian Haul</a>
* @version CVS $Id$
*/
public class RequestParameterExistsAction extends AbstractConfigurableAction
{
protected static class StringParts {
String prefix = null;
String pstfix = null;
int count = 0;
public StringParts (String pre, String post) {
prefix = pre;
pstfix = post;
}
}
public Map act( Redirector redirector,
SourceResolver resolver,
Map objectModel,
String source,
Parameters parameters
)
throws Exception {
Request request = ObjectModelHelper.getRequest(objectModel);
HashMap results = new HashMap();
HashMap items = new HashMap();
int wildcards = 0;
// check default parameters for existence
if (this.getLogger().isDebugEnabled()) {
getLogger().debug("checking default parameters");
}
Iterator reqParams = settings.values().iterator();
while (reqParams.hasNext()) {
String paramName = (String) reqParams.next();
StringParts sp = splitParameter(paramName);
if (sp != null) {
// wildcard: special care required (deferred until later)
items.put(new Integer(wildcards++), sp);
if (this.getLogger().isDebugEnabled()) {
getLogger().debug("(default) deferring " + paramName);
}
} else {
String paramValue = request.getParameter(paramName);
if (paramValue == null) {
return null;
}
results.put(paramName, paramValue);
}
}
// check parameters for existence
if (this.getLogger().isDebugEnabled()) {
getLogger().debug("checking sitemap parameters");
}
String params = parameters.getParameter("parameters", null);
if (params != null) {
StringTokenizer st = new StringTokenizer(params);
while (st.hasMoreTokens()) {
String paramName = st.nextToken();
StringParts sp = splitParameter(paramName);
if (sp != null) {
// wildcard: special care required (deferred until later)
items.put(new Integer(wildcards++), sp);
if (this.getLogger().isDebugEnabled()) {
getLogger().debug("deferring " + paramName);
}
} else {
String paramValue = request.getParameter(paramName);
if (paramValue == null) {
return null;
}
results.put(paramName, paramValue);
}
}
}
if (wildcards != 0) {
// special care for parameters with wildcard
//
if (this.getLogger().isDebugEnabled()) {
getLogger().debug("deferred checking for parameters: " + wildcards);
}
// first one
//
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(" checking first");
}
HashMap values = new HashMap();
StringParts sp1 = (StringParts) items.get(new Integer(0));
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
" Parameter is [" + sp1.prefix + " * " + sp1.pstfix + "] ");
}
Enumeration requestParams = request.getParameterNames();
Boolean dummy = Boolean.TRUE;
while (requestParams.hasMoreElements()) {
String paramName = (String) requestParams.nextElement();
String match = getMatch(paramName, sp1);
if (match != null) {
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
" value is >"
+ match
+ "< "
+ sp1.prefix.length()
+ " "
+ paramName.length()
+ " "
+ sp1.pstfix.length());
}
values.put(match, dummy);
sp1.count++;
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
" Parameter "
+ sp1.prefix
+ "*"
+ sp1.pstfix
+ " matches "
+ paramName
+ " ("
+ sp1.count
+ " so far)");
}
String paramValue = request.getParameter(paramName);
if (paramValue == null) {
return null;
}
results.put(paramName, paramValue);
}
}
if (sp1.count == 0) {
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
" Parameter "
+ sp1.prefix
+ "*"
+ sp1.pstfix
+ " matches "
+ sp1.count);
}
return null;
}
// all other ones
//
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(" checking others");
}
requestParams = request.getParameterNames();
while (requestParams.hasMoreElements()) {
String paramName = (String) requestParams.nextElement();
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(" checking request parameter " + paramName);
}
for (int i = wildcards - 1; i > 0; i--) {
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(" checking against " + i);
}
StringParts sp = (StringParts) items.get(new Integer(i));
String match = getMatch(paramName, sp);
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
" Parameter is ["
+ sp.prefix
+ " * "
+ sp.pstfix
+ "] ");
}
if (match != null) {
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
" Parameter "
+ sp.prefix
+ "*"
+ sp.pstfix
+ " matches "
+ paramName
+ " ("
+ sp.count
+ " so far)");
}
if (values.containsKey(match)) {
sp.count++;
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
" " + paramName + " (verified)");
}
String paramValue = request.getParameter(paramName);
if (paramValue == null) {
return null;
}
results.put(paramName, paramValue);
} else {
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
"Match "
+ match
+ "not found for "
+ sp1.prefix
+ "*"
+ sp1.pstfix
+ " but for "
+ sp.prefix
+ "*"
+ sp.pstfix);
}
return null;
}
}
}
}
// since we enforce that only matches are counted, that exist for
// the first parameter as well, check if every parameter has an
// equal number of matches.
//
if (this.getLogger().isDebugEnabled()) {
getLogger().debug("checking number of matches");
}
for (int i = wildcards - 1; i > 0; i--) {
StringParts sp = (StringParts) items.get(new Integer(i));
if (sp.count != sp1.count) {
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
"Found "
+ sp.count
+ " matches for "
+ sp.prefix
+ "*"
+ sp.pstfix
+ " but expected "
+ sp1.count);
}
return null;
} else {
if (this.getLogger().isDebugEnabled()) {
getLogger().debug(
"Found "
+ sp.count
+ " matches for "
+ sp.prefix
+ "*"
+ sp.pstfix
+ " as expected");
}
}
}
}
return Collections.unmodifiableMap(results);
}
/**
* Find first "*" in a String and split it into the substring
* before and after the "*". Returns null if no "*" is present.
*/
protected StringParts splitParameter( String paramName )
{
int idx = paramName.indexOf("*");
if ( idx != -1 ) {
return new StringParts(paramName.substring(0,idx), paramName.substring(idx+1));
} else {
return null;
}
}
/**
* If a String matches a StringPart spec, return the substring
* between the specified prefix and postfix. Returns null if it
* doesn't match.
*/
protected String getMatch( String paramName,
StringParts sp
)
{
if ( paramName.startsWith( sp.prefix ) && paramName.endsWith( sp.pstfix ) ) {
return paramName.substring( sp.prefix.length(), ( paramName.length() - sp.pstfix.length() ) );
} else {
return null;
}
}
}